Author Topic: Tores mailbox VIIC and VIIC/41 operation and technical details  (Read 655192 times)

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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3600 on: 30 Mar , 2017, 03:34 »
Hello Mr. Tore,


When docking and during maintenance - if the fuel oil transfer pump was used to drain the fuel storage tanks, and no diesel engines are running so this source of water cooling compensating water is not available. How would they get the fuel oil from the storage tanks. The transfer pump is trying to draw fuel oil from the top of the tanks, I don't see what pushes the oil up??? unless they use the Auxiliary water cooling pump to force water through the diesel engines and then on to the header tank....

this issue was discussed on page 75 of Skizzenbuch.

Regards,
Don_
« Last Edit: 30 Mar , 2017, 03:42 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3601 on: 30 Mar , 2017, 05:29 »
Don.
In the unlike event of a major docking/repair with full fuelbunker tanks, the easiest way to empty the  fueltanks would be to use the aux, coolingwater pump to pressureize the compensating system as indicated on the image below, prior to entering the drydock. If this is not done while afloat, you might use a hose suctionconnection on the aux coolingwaterpump to a watersupply (yellow). The last oportunity would be to use the aux. luboil pump hose connection via the manholes.
Tore
« Last Edit: 30 Mar , 2017, 11:08 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3602 on: 31 Mar , 2017, 20:03 »
Hello Mr. Tore,


U-93 through U-97 had 2 e-compressors
U-98 and above had 1 e-compressor and 1-Junkers compressor


Did U-92 and below only have 1 e-compressor?


Regards,
Don_
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3603 on: 01 Apr , 2017, 00:16 »
Don.
As you know the VIIC was a further developement of the VIIB, the last VIIB submarine was commissioned in 1941 I guess.  You had an overlapping periode when the VIIC was introduced in 1940. I assume the first VIICs had two E compressors as the VIIBs and when the Junker freepiston compressors were introduced, they had quite some trouble related to the exhaust backpressure resulting in various exhaust outlet alternatives. In the transition periode the  VIIC boats U 93 through U 97 were equipped with two e-compressors. The highest pennant no. of the VIIB class was U-102, but it is no relation with the German pennant no. and commission year.
Tore
« Last Edit: 01 Apr , 2017, 01:00 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3604 on: 04 Apr , 2017, 15:43 »
Hello Mr. tore,


In 1943 the Germans moved the hand wheel for venting the bow buoyancy tank from the forward torpedo room to the forward control room pressure hull above the hatch on the starboard side.


This was a significant and intentional change... I assume that the Germans wanted to vent the bow buoyancy tank to decrease the diving time; especially on a U-boat with the wider Atlantic bow. They would not need to vent the bow buoyancy tank on a standard dive, but in an Alarm Dive it may be advantageous...


In order to keep the horizontal balance, then I assume they would vent the aft buoyancy tank as well. The bow buoyancy tank would not need to be blown when surfacing because of the bow angle and height and with the open slots at the bottom of the tank; it would naturally drain. The only issue would be blowing the aft/stern buoyancy tank in this scenario, and that should be a normal function for the aft torpedo room crewman who have to assure the aft buoyancy tank is blown before starting the Junkers air compressor...


Comments?

Where is the stern buoyancy tank blowing valve located it the aft torpedo room?

Regards,
Don_
« Last Edit: 04 Apr , 2017, 16:22 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3605 on: 05 Apr , 2017, 01:14 »
Don.
I guess the developement of the buoyancy tanks is a bit more complex and has to be seen in conjunction with the VIICs developement from the VIIBs. When the VIIC was designed they lengthened the pressurehull to be able to accommodate more equipment. At the same time they were able to introduce the Untertriebcelles (Q Tanks) in the saddletanks. At the time these changes were made a submarine was still a surfacevessel able to dive, rather than a true submarine, and as the radar was still not an instrument regulary in use surface cruising was done to and from the battlefield and an improved surface condition was neccesary. As a concequence of the improved surface behaviour, the buoyancy tanks were a problem as they increased the "surface resistance" when diving, which lead to filling the Q tanks while cruising on the surface to overcome the surface resistance in the event of crashdiving. In case of bad wheather, this would make life hard for the people on the bridge and empty buoyancy tank as well as a later introduced Atlantic bow  would improve the matter. It is important to emphasize that the buoyancy tanks are not ballast tanks but merely tanks for surface improvements and do not take part in the diving/ surfacing procedure thus the are to be considered as free flood areas when diving.
I agree with your conclusion on the blowing of the buoyancytanks as well as the aft buoyancytank blowing when operating the Junker compressor. As you know an interlock was installed in the Junker exhaustsystem preventing to open the exhaustvalve unless the vent for the aft buoyancy tank was shut.
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3606 on: 05 Apr , 2017, 21:41 »

Hello Mr. Tore,


I don't believe there is any need to blow the stern buoyancy tank if they vented the Atlantic Bow buoyancy tank because the buoyancy tank's effect on the longitudinal balance becomes insignificant with depth.


Bow Buoyancy Tank Vol (m3) - Versus Depth (m)       Stern/aft Buoyancy Tank Vol (m3) – Versus Depth (m)
                 8                                  sea level                                       4.28                               sea level
                 1.34                             50                                                 0.72                               50
                 0.73                             100                                               0.39                               100
 
At 100 meters depth, the volume of the air in the aft buoyancy tank is 0.39 m3 and this calculation has not considered the volume change due to cooler water temperature with depth (reduces the volume again)!


What do you think?


Regards,
Don_
« Last Edit: 05 Apr , 2017, 21:43 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3607 on: 06 Apr , 2017, 02:17 »
Don.
As I said before the buoyancy tanks are not ballasttanks and do not participate in the diving and surfacing procedure, when  diving and surfacing the vents are open and the tanks are to be considered as freeflood areas. Surfaced they are elements in reducing the pitching of the submarine by shutting the vents.
Tore
« Last Edit: 06 Apr , 2017, 02:19 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3608 on: 07 Apr , 2017, 03:03 »
Hello Mr. Tore,


Do you or Maciek know which valve in the aft torpedo room is used for blowing the aft buoyancy tank?


Also, what is this hand-wheel for in the attached photo in the red circle?


Regards,
Don_
« Last Edit: 07 Apr , 2017, 03:09 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3609 on: 07 Apr , 2017, 04:01 »
Hello Mr. Tore,


On page 420 in Skizzenbuch you are talking about a uhistoria.com image...  Where is this image?


"The linkage consists of a bell crank lever which snaps the cones in a locked in position. On the u-historia.com photo you see the worm rod and the piston rod fixed to a yoke having two guide rods. At the ends of the guide rods are some peculiar "nuts." These are spring loaded end stoppers; when the linkage snaps into position they push the actuating lever a fraction back to release the engagement at the shaft slide to prevent a possible hot running."


Regards,
Don_
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3610 on: 07 Apr , 2017, 07:11 »
Don.
The U historia images are found on the U historia homepage, look to Visita Guida then Sistema Embrague which is the mainengine clutch. Since I wrote my comments on the clutches I got hold of Falos photos which are at least as good if not better. A small correction could be nessecary with regards to the hand operation of the clutch. I introduced a key and a sliding slot, as Falos images are better I discovered a locking bolt which might be used to fix the travelleing nut to the yoke assembly in case of handwheel operation.
Tore
« Last Edit: 07 Apr , 2017, 13:03 by tore »

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3611 on: 07 Apr , 2017, 07:22 »
Don
Blowing of buoyancy tanks. I cannot find the LP air valve to the stern buoyancy tank. The buoyancytanks were not connected to the tankblowing system, but had a branch off from the ordinary LP system, like weedblowing and mainengine clutches, if you have images showing the LP pipes from the aft engine room it might be possible to trace the valve for the stern buoyancy tank. The handwheel in the red circle I cannot identify, may be Maciek has a clue.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3612 on: 07 Apr , 2017, 10:19 »
Tore, what means LP?

Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3613 on: 07 Apr , 2017, 10:54 »
Tore, what means LP?


I will answer this question: LP means low pressure air.


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Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3614 on: 07 Apr , 2017, 11:40 »
Thanks.

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3615 on: 07 Apr , 2017, 14:49 »
Hello Mr. Tore and Maciek,


The hand-wheel for operating the stern buoyancy tank vent valve; it's position (between 6th and 7th frame) corresponds with the drawing:



http://www.uboatarchive.net/U-570/U-570DTPlate28.jpg


That means that the level near the Junkers exhaust valve (and interlocked with it) is not for operating the buoyancy tank vent valve, but for something else. Moreover, this lever (as well as exhaust valve) is located between 7th and 8th frame) and it does not match with the plate:


http://www.uboatarchive.net/U-570/U-570DTPlate28.jpg


So it has to be for something else. It is definitely interlocked with exhaust hull valve. I guess maybe it is some external flap of the exhaust duct?


1. The hardware in U-995 indicates the stern buoyancy tank hand-wheel still exists and is operational.
2. Linkage between the lever actuator and the stern buoyancy tank hand-wheel looks doubtful.
3. What is the lever actuator/interlock function?
4. The interlock lever drive shaft goes external to the pressure hull to control something?


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3616 on: 08 Apr , 2017, 03:42 »
Hello Mr Tore,


I have taken what you previously provides and made some changes...



Drawing attached
 
1. 1st State - Junkers compressor not active - Exhaust flap valve shut and the grinding plate valve is shut (submerged)
2. 2nd State - transitional
3. 3rd State - Junkers compressor active - Exhaust flap valve open and the grinding plate valve is open and the diesel exhaust is directed to the external water cooled muffler

What do you think?


Regards,
Don_
« Last Edit: 08 Apr , 2017, 13:22 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3617 on: 12 Apr , 2017, 03:26 »
Hello Mr. Tore,


I have been working on the Junkers exhaust system and came up with what I believe may be the internal drive of the outer segment. This doesn't look to be a difficult gearing design since I had to work on NCR mechanical cash registers when I was 22 years old.


However, I have ran into a problem with the exhaust system.  It looks like the intermediate disk up near the upper pressure hull is out of time or sync...


I will attach a photo and the problem is marked.


Please advise...


Regards,
Don_
« Last Edit: 12 Apr , 2017, 03:51 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3618 on: 12 Apr , 2017, 14:52 »
Hello Mr. Tore,


I believe I know what happened to get the upper drive segment out of sync...  The hand-wheel provides a great mechanical advantage when applying force to its drive shaft. Then you can multiply that force times 10 with the final stage gear drive.


The final stage drive gear is taper pinned (heavy) to the drive shaft along with the lighter upper drive segment (smaller) taper pin. If for some reason the lever that locks the intermediate gear was not moved to the unlock position, and there was driving force applied to the hand-wheel, then you have a situation.  The force applied to turn the final stage gear, is applied to the segment meshed to the intermediate plate gear which can not be turner and will result in the small taper pin holding the segment to the drive shaft to shear.


Now, the relationship between the final stage drive gear and the upper drive segment no longer exists and there is no drive to the segment (it's broken)!!!


What do you think?


Regards,
Don__
A man's got to know his limitations...
Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3619 on: 12 Apr , 2017, 16:09 »
Hello Mr. Tore and All,


If you zoom on my image, then it looks like the intermediate wheel is missing some teeth.  If someone has a better resolution image, then this can be confirmed...


Regards,
Don_
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Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3620 on: 12 Apr , 2017, 16:24 »
Hello Karel,


I will provide you with a link to Skizzenbuch once I get the junkers exhaust issue settled.  However, this version of Skizzenbuch will be in a PDF format and is not copy protected.  Therefore, on the condition that you will not distribute this version, then you are welcome to it.  Eventually I will get a program called "CopyProtect" which will allow the distribution of a PDF, but under the writers control (it encrypts the PDF and comes with an embedded viewer)...


The next time I post a new version of Skizzenbuch to my dropbox folder, then I will send you a link.  Please send me an email so that  I may use it to send you the link.


My email address is:


donprince5207@comcast.net


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3621 on: 13 Apr , 2017, 00:24 »
Hello Mr. Tore,


I have worked on an Junkers exhaust system based on the outer photos that are available...  Please advias as to your opinion which is highly valued.


Regards,
Don_
« Last Edit: 13 Apr , 2017, 23:09 by Don Prince »
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Offline karel

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3622 on: 13 Apr , 2017, 01:32 »

Hello Don.This is wonderful news. I have sent you an email.


Thank you


Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3623 on: 14 Apr , 2017, 02:03 »
I posted the latest version of Skizzenbuch 11 - 17 - M + I.pdf in the dropbox folder.


I expect there may be some changes after Mr. Tore and Maciek review the latest version.


Regards
Don_
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Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3624 on: 14 Apr , 2017, 16:47 »
Hello Mr. Tore,


The GW diesel engine had an RPM counter that looks to turn over at 1,000,000 rpm...  If the diesel engine was running at an average of 390 rpm, then it would take about 42 and 3/4 hours for the counter to turn over.  Was there some sort of a maintenance scheduled at a turn over? If not, then what is the purpose for this counter?


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3625 on: 15 Apr , 2017, 08:22 »
Don,

to be strict, this is revolution counter, not RPM counter.
In my opinion, the turn-over value indicates that it was supposed to read off every 24 hour, and then the values were sum-up.
I cannot give you any schedule-periods, but engine revolutions as well as working ours were recorded in the KTB Maschine.
Some U-Boat KTBs had attaches: radio logs, maps, torpedo reports or engineering logs (KTB Maschine). In the engineering logs were recorded all information related with mechanical equipment of the U-Boat (among the others data related with diesel engines: fuel consumption, working time and so on). At the uboatarchive.net website are available some engineering logs.
For example:
http://www.uboatarchive.net/U-107/KTB107-6KTBMaschine.htm
PortMotorStbMotor
DaysHoursMinDaysHoursMin
Total operating time since commissioning:22018332211530
Total operating time during the last patrol:37737372215
Revolutions since commissioning:8314859684922374
Revolutions during the last patrol:1339818014144920

http://www.uboatarchive.net/U-518/KTB518-2KTBMaschine.htm
stb engine
operating time since commissioning: 2603 hours 4 min
operating time during last patrol: 943 hours 56 min
revolutions since commissioning: 33,349,060
revolutions during last patrol: 11,341,510

port engine
operating time since commissioning: 2598 hours 10 min
operating time during last patrol: 960 hours 28 min
revolutions since commissioning: 36,043,720
revolutions during last patrol: 11,412,440

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Regards
Maciek

Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3626 on: 15 Apr , 2017, 10:00 »
If you zoom on my image, then it looks like the intermediate wheel is missing some teeth.  If someone has a better resolution image, then this can be confirmed...

Maybe this photo is better.

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Regards
Maciek

Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3627 on: 15 Apr , 2017, 14:23 »
Hi Gentlemen,

while looking through the KTB Maschine, in this document I have found the following (the section regarding the issues with Junkers compressor):
Quote
After disassembly of the internal exhaust gas valve, it was found that the seat of the valve was burnt or ground out over half of its perimeter.  Repair was not possible by on board means.  The external valve is tight.

This fragment indicates that Junkers compressor exhaust hull valve consisted of internal and external part (what was not so obvious for me).
Maybe it looked as follows: in the early years of war, both valves were driven by two hand-wheels. This hand-wheels are visible at this photo taken on U 570:

Left hand-wheel drives the internal valve (water-cooled casing with thermalinsulation) while the right hand-wheel drives external valve (and that's why it does not have thermalinsulation, it is just a shaft going through the hull). Both valves are driven by hand-wheels and are fitted with valve state indicators. To close or open the valves, many turns are required, so one can recognize them as "slow-working" valves. That means that it took long time to open both valves fully, and before it was done, seawater breaks into the exhaust system.

When German recognized this problem, in the later U-Boats (like U 995) they interlocked the external and internal valves in such way that external flap could only be opened when internal valve was opened previously. In this design, hand-wheel driven, "slow-working" internal valve would be opened fully, and only then, external flap could be opened by "fast-working" lever (this lever could be rotated by ~330 deg, so it has lower radio-gear, requiring a greater force, and that's why long lever was provided). In the same time when the external flap was opened quickly, the Junkers compressor was started, and exhaust pressure did prevent water intrusion.

Generally, this idea is concurrent with Don's idea presented in his post.

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Regards
Maciek

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3628 on: 16 Apr , 2017, 07:06 »

Don and Maiek.
Regret I had to leave my mailbox for a while due to some family matters. I am just home for a few days before I leave up to my summerfarm for the year on late tuesday. My problem is then I am not sure when I get access to the internet, hopefully in a few days, may be wednesday/ thursday  April 26/27, sorry about this. I have briefly read the various proposals on the Junker and as I remember some of the " designs" I made on the exhaust system was, as I mentioned at the time, pure guesswork in lack of documentation. In the meantime Maciek has come up with an interesting image which together with Dons  sketches might give a better understandings on the matter. I shall look into this again, just a preliminary remark Don, the hull exhaustvalve normally shuts having the seapressure behind the valvedisc which means, I guess, the valvedisc on you sketch should be in the top chamber on you image.
Tore
« Last Edit: 16 Apr , 2017, 07:08 by tore »

Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3629 on: 16 Apr , 2017, 12:32 »
Hi Tore,

it's great to hear from you again.

Gentlemen, if I recall correctly, some time ago we had discussed briefly (however I cannot find particular posts) about safety pins (or safety seals) securing the vent valves from being accidentally opened.

I have found few photos taken aboard of HMS Graph. They are showing the MBT 5 vent hand-wheel secured with locking pin, and MBT 3 port vent lever secured and unsecured.

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Maciek

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3630 on: 16 Apr , 2017, 13:34 »
Thank you Maciek.  Nice images of the vent locking pins.
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3631 on: 16 Apr , 2017, 18:03 »
Hello Mr. Tore,


 I hope all is well with you and your family... Happy Easter!


I thought about the location of the exhaust valve plate and the shutting direction.  There were three reasons for this particular proposed design:


1. I drew it with the shaft raising upward and shutting the valve because when you turn a valve clockwise the hand-wheel and valve stem would generally move into the valve housing to shut the valve (grind the valve plate and seat in this instance). Also, the valve was mounted upside-down in the exhaust system.


2. When the hand-wheel is turned counter clock-wise to fully open the plate valve, then the rotating hollow valve stem shaft moves downward into the housing, and is not exposed to the exhaust heat or a carbon buildup.


3. When the external flap valve is shut, then it has the external water pressure applied to it. Therefore, the exhaust plate valve should not experience these water pressures.


What do you think?


Kind regards,
Don_
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3632 on: 17 Apr , 2017, 00:11 »
Thank you Don.
If you look at the main engine exhaust hullvalves you see the principle, and I guess it is possible they followed the same system on the Junker exhaust. Allthough the outer Junker exhaust valve was not used as a damper, you would experience carbon deposite on the outer exhaustvalve causing leakages as the Junker was a two stroke diesel and more susceptible to carbonization. I agree with your philosophy of shutting valve by turning the handwheels clockwise. I guess we could overcome that by using anticlockwise threads operating the valvestem.
Tore 
« Last Edit: 17 Apr , 2017, 00:14 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3633 on: 17 Apr , 2017, 21:22 »

Hello Mr. Tore,


After reviewing Maciek's info from a U-Boat KBT log which states the following:


"After dis-assembly of the internal exhaust gas valve, it was found that the seat of the valve was burnt or ground out over half of its perimeter.  Repair was not possible by on board means.  The external valve is tight."


It would be virtually impossible to take apart the exhaust valve system and separate it from the outer exhaust casing if the exhaust valve plate extended up into the upper chamber; the valve plate would have to move through the valve seat.


When the valve seat was damaged, they could see that burned and worn out areas. The valve seat must have been face downward because I don't believe they would have disassemble the outer exhaust casing.


However, they could separate the lower exhaust valve system from the upper pressure hull and exterior exhaust casing to inspect the valve plate and the valve seat from inside the pressure hull.


What do you think...


Regards,
Don_

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Harry Callahan, SFPD

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3634 on: 18 Apr , 2017, 01:23 »

Hello Mr. Tore, Maciek, and All,


Mr. Tore - I have checked the Type VII C training manual and the word "Grease" is not there...  With the initial supplies was there some type of container of grease brought on-board?


Maciek - I made the changes suggested on pages 71, and 314, is this OK?


Mr. Tore - When ever you have the time (there is no real hurry for this because I have to do some yard work at home that I need to catch up on).


I hope I have my understanding of the Lubrication Oil problems resolved this time...


Page 72 - 73
Page 85
Page 97 - 99
Page 108 - 109
Page 125 - 126
Page 142 - 150
Page 176 - 177
Page 180
Page 429


I just uploaded the latest version of Skizzenbuch into my Dropbox folder...


Mark and Karel - I believe Skizzenbuch is very close to a finished product, and most likely there will be a correction version.  However, If you all see anything wrong, no matter how trivial, then please let me know. I would like Skizzenbuch to be accurate and easy to read and understand as possible.


Mr. Herrn Klaus Mattes will meet with Annemarie Bredow (Uboot-Museum) and with members of the German IMMH on April 22rd, and the day before that he attend a meeting and will present Skizzenbuch at the annual meeting of Uboat Wilhelm Bauer where he hopes to be re-elected to the board.


Skizzenbuch will most likely become a Website book and not a printed book because of the expense incurred with a printed edition.  However, my final version of Skizzenbuch will be encrypted with an embedded reader; it will not allow changes, but will permit printing the book...


Regards,
Don_
« Last Edit: 18 Apr , 2017, 01:31 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3635 on: 18 Apr , 2017, 01:40 »

Don.
The only reliable source we have for the old exhaustsystem of the U 570 execution, is plate 13 showing the coolingwater system. By comparing that with the U 570 images shown by Maciek I guess the KTB is refering to the inner exhaustvalve ( inside the pressurehull) which has its inner casing flange inside the pressurehull hence it is possible dismantle the valve disc into the compressor room. As shown on the plate a leaking outer exhaust valve shall fill the space before the inner valve, just as on the main engine system, hence a proper draining of that space as shown is nessecary. Contrary to the main engine system when we got the cylinders filled water, we turned the engines with open indicatorcocks, this is not possible with the Junker and as a last precausion a watersaparator was installed just before the compressor . A burned valvedisc as reported in the KTB might very well derive from a carbon deposit on the seating creating a local leaking jet acting as a burner on the seating. This is one of the reasons for grinding the deposits away as soon as possible. As I told before if you had such a difficult deposit on the seatings  we very often allowed the seapressure to act on the valve disc to increase the pressure against the seatings while grinding. This is one of the advantages to have the valves shutting with sea backpressure. On the image below I have tried to explain the system. I agree with Macieks theorie.
Tore
« Last Edit: 18 Apr , 2017, 01:43 by tore »

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3636 on: 18 Apr , 2017, 03:55 »
Hello Mr. Tore,


Did the old original Junkers exhaust system have the ability to grind the inner valve  and seat? 


http://uboatarchive.net/U-107/KTB107-6KTBMaschine.htm
War patrol from 21.4. to 11.7.1942 (6th War Patrol)


The KBT came from U-107 which was a Type IXB that was commissioned on 8.10.40. Would  U-107 have been upgraded with the new exhaust system?


U-107 was lost on 18.8.44 and no survivors...
A man's got to know his limitations...
Harry Callahan, SFPD

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3637 on: 18 Apr , 2017, 04:27 »
Hello Mr. Tore,


I just thought about something that is very obviously different about the GW Diesel engine exhaust system design and the proposed Junkers exhaust system design:


The GW diesel engine exhaust design uses a beveled gear to swing a large valve shut with not a great deal of force. Therefore, the valve grinding and external seawater pressure is needed to force shut a fairly large diameter valve.


The Junkers compressor valve (proposed design) would be a fairly small diameter plate valve and it is being driven positively shut by the hand-wheel at the bottom of the internal exhaust casing. This type of valve shutting would not need the seawater force to help shut the valve...


What do you think?


Good night it's 6:27 AM...


Kind regards,
Don_
« Last Edit: 18 Apr , 2017, 04:29 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3638 on: 18 Apr , 2017, 05:31 »
Don.
I don`t know much about the developement story of the Junker exhaust system. As they had a fairly long history of troubles before they came to the last construction, I assume there are several alternatives fitted on the various boats. I don`t know, but I would be astonished if they skipped the grinding possibility of the innervalve.  I guess a grindig connection could be as proposed on my image below.
It was never a problem to shut the main engine exhaust dampers by operating the handwheels and no need for any external force. However when a carbon deposit was formed on the seating, external force (seapressure) helped the grinding pressure as a possible strong shutting force exerted by the valveshutting mechanism would increase the pressure resistance on the valvedisc pivot. As told before at some 3-4 meters the sea backpressure prevented the operating of the pneumaic grinding motors without a pivoting shutting force.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3639 on: 18 Apr , 2017, 13:38 »
Don, Maciek.
I am moving to my summerfarm tomorrow morning, which mean I shall be without the net fo a few days reverting as soon as I can.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3640 on: 21 Apr , 2017, 23:37 »
Hello Mr. Tore, Maciek, and All,


I have been struggling with the Junkers Exhaust System...


The first issue was getting the gearing to match up with what is present locking segments in the upper pressure hull --- and the fix was to add another gear to my gear assembly and now I have a match when the internal exhaust grinding valve is shut and the segments on the upper hull. Nothing is out of time or sync!


The second issue was getting the segment to line-up with the external exhaust flap valve locking cam  on the upper pressure hull.


a) with a new grinding valve and seat - no problem
b) with a worn grinding valve and seat - big problem because everything moves too further.


I believe the resolution to that problem is to have a very heavy compression spring to close the grinding valve and allow the gear assembly to move to the point where the exhaust flap valve needs to lock the movement. I believe the use of the compression spring buffers the valve wear issue.


I searched the internet and there are die and clutch springs that are rated at 1200 - 1500 pounds. So these springs are good for a depth of 250 -300 meters and beyond...


I have attached the new images - what do you all think?


Kind regards,
Don_
 
« Last Edit: 21 Apr , 2017, 23:43 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3641 on: 22 Apr , 2017, 03:07 »
Hello Mr. Tore and Maciek,


I placed the latest version of Skizzenbuch in my Dropbox folder...  Maciek, I corrected pages 431 and 438, thanks again....


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3642 on: 22 Apr , 2017, 06:36 »

Hi Don,

I placed the latest version of Skizzenbuch in my Dropbox folder...  Maciek, I corrected pages 431 and 438, thanks again....


Page 431 looks good, but on page 438 you have mistakenly marked the valve for closing Schnorchel air intake duct as "Schnorchel Locking Pin Hand-wheel". I have marked (with green color) the position of this valve on the attached drawing. Without this valve, when the Schnorchel is lowered, while the boat is submerged, the diesel engine intake duct would be flooded.


BTW, on page 425, on the sketch of the 1st generation Schnorchel system, number 6 means "Schnorchel flooding valve", not "Schnorchel draining valve". This valve was needed to flood the part of air intake duct (between ventilation mast air intake and Schnorchel mast) prior to lowering the Schnorchel mast (to equalize pressure inside the duct with the outside sea water pressure).


--
Regards
Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3643 on: 22 Apr , 2017, 09:49 »

Hi Don,

I have been struggling with the Junkers Exhaust System...

[...]

I have attached the new images - what do you all think?


If I understand correctly, in your design you assume that external exhaust flap (driven by lever) is interlocked with grinding plate?


Personally I think (as I tried to explain in this post) that external exhaust flap is interlocked with internal exhaust valve. However I do not have any hard evidence to support this opinion.


Regarding the Skizzenbuch: page 97
Quote from: Sizzenbuch
In addition, I assume a second exhaust valve was introduced outside the pressure hull which has an air connection on the water side to blow the exhaust pipe between the valve and the muffler and operated from inside the pressure hull, with interlock to the aft buoyancy vent valve as previously discussed. As a final countermeasure a water-trap was fitted just before the Junker exhaust outlet as indicated on the system image Plan 13 for the GW engines (See partial plan below right).
In this fragment you are talking about interlocking the exhaust valve with aft buoyancy tank vent valve. I guess that part was not corrected during your latest updates.
Quote from: Sizzenbuch
However, for U-995, it looks like the external exhaust control lever next the Junkers compressor exhaust valve grinding mechanism works with the interlock which prevents shutting the grinding plate exhaust valve while the Junker compressor is operational and passing its exhaust gases to the water cooled muffler.
As I mentioned before, I have different opinion on this matter, however I cannot proof it.
One note: the design you propose prevents shutting the grinding plate while external exhaust flap is opened (which is not exactly equivalent to the Junkers compressor running).


And final note: we are still missing the proposal, how and where exhaust duct from Junkers compressor was connected to the housing of the valve.


--
Regards
Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3644 on: 22 Apr , 2017, 17:23 »
Hi Maciek,


How about this for a proposal of the entire system...


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3645 on: 23 Apr , 2017, 01:22 »

Hi Don,

How about this for a proposal of the entire system...


Where the compressor exhaust duct penetrates the pressure hull?


--
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Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3646 on: 23 Apr , 2017, 01:54 »
Hello Maciek,


Where does the exhaust pipe penetrate the pressure hull...  Hmmmm! I thought that you or Mr. Tore would be the better person to answer that question.  I would think it would be somewhere near the back side of the Junkers compressor close to the water trap.  I sure hope it wasn't at the location of what is now the entrance door. The short answer is "I Don't Know"... 


I just uploaded a corrected version of Skizzenbuch into my Dropbox folder...


Page 98 - Internal Exhaust Valve = Internal Exhaust Grinding Plate Valve
                External Exhaust Valve = External Exhaust Flap Valve


Page 438 corrected, My fault I circled the wrong valve...  Now I identified both valves.


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3647 on: 23 Apr , 2017, 02:13 »

Hi Don,

Where does the exhaust pipe penetrate the pressure hull...  Hmmmm! I thought that you or Mr. Tore would be the better person to answer that question.  I would think it would be somewhere near the back side of the Junkers compressor close to the water trap.  I sure hope it wasn't at the location of what is now the entrance door. The short answer is "I Don't Know"... 


It was a bit tricky question.  I'm pretty sure that exhaust duct was connected to the upper part of the inner valve casing (similarly as on attached photo from U 570 - marked with red dots).
There is no reason to make another opening in pressure hull (which of course also has to be protected with hull valve - most likely also water cooled).


--
Regards
Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3648 on: 23 Apr , 2017, 02:51 »
Hi Maciek,


The approach to the junkers exhaust exit looks to be much simpler in the Type IX C built 7.8.43,  They have a selector valve that dumps any water from the exhaust pipe to the bilge...  There is no water separator, and the internal exhaust goes to the internal exhaust valve casing, but nothing is shown at the exterion of the pressure hull...


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3649 on: 23 Apr , 2017, 04:15 »

Hi Don,

The approach to the junkers exhaust exit looks to be much simpler in the Type IX C built 7.8.43,  They have a selector valve that dumps any water from the exhaust pipe to the bilge...  There is no water separator, and the internal exhaust goes to the internal exhaust valve casing, but nothing is shown at the exterion of the pressure hull...


This diagram shows only that valve casing is water-cooled. The piping does not drain the exhaust valve. The f2 selector valve is primarily used for injecting anti-corrosion agent into compressor cooling system and secondarily for draining the cooling system.


--
Regards
Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3650 on: 23 Apr , 2017, 23:08 »
Hello Mr. Tore and Maciek,

The exhaust separator on U-995 looks a little more advanced than the one on U-570.  U-570's separator looks to be positioned higher, but it looks like U-995's separator had a pressurized drain system... I believe there are two drain pipes at the top of U-995's separator.


There may be a sight glass and a valve cut-off on the upper drains, or some type of a float valve inside the separator because they don't want exhaust fumes going to the bilge and then throughout the pressure hull...


What do you think?


Regards,
Don_
« Last Edit: 23 Apr , 2017, 23:17 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3651 on: 23 Apr , 2017, 23:33 »
After seeing this image from SUBSIM, It looks like the separators on U-570 and U-995 ate at the same height.


...and, Maciek notice there are two (2) tanks below the Junkers compressor.


Regards,
Don_
« Last Edit: 23 Apr , 2017, 23:36 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3652 on: 25 Apr , 2017, 22:23 »
Hello Mr. Tore,


I hope all has gone well with you and your wife moving to your country home.  I myself would not have the will or stamina to take care of two homes and maintain the grounds.  Do you have someone to stay in either home while you are in the other one? I would think that your country home in the winter may have water pipes freezing unless the hearing is maintained at a decent level in the home. Although, being in a country home during the Spring and Summer is a welcome way to relax and enjoy life. However, my wife Maureen is from the over crowed city of Jakarta, Indonesia, 10 million people and growing and she does not like to live in the country. Before moving to Georgia, we lived just outside of Lexington, South Carolina, with a population of about 20,000 people; she called it the village! Now, we live about 30 miles north of Atlanta, Georgia, where the congestion is creeping north ever so slowly...


I have updated Skizzenbuch with the latest info from Maciek, and added a colored cover and trailer page like many hardbound books. Sometimes it's not expansive to go first class...


Kind regards,
Don_
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Harry Callahan, SFPD

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3653 on: 27 Apr , 2017, 01:28 »
Hi Don,

The exhaust separator on U-995 looks a little more advanced than the one on U-570.  U-570's separator looks to be positioned higher, but it looks like U-995's separator had a pressurized drain system... I believe there are two drain pipes at the top of U-995's separator.


There may be a sight glass and a valve cut-off on the upper drains, or some type of a float valve inside the separator because they don't want exhaust fumes going to the bilge and then throughout the pressure hull...

On the photos from U 570 you are considering water separator of the Junkers exhaust system, while on the photos from U 995 there is another separator: at the output of the air compressors.

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Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3654 on: 27 Apr , 2017, 01:40 »
...and, Maciek notice there are two (2) tanks below the Junkers compressor.

You are right Don, there are two flasks under Junkers compressor. Maybe these are flasks with starting air?

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Regards
Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3655 on: 27 Apr , 2017, 03:31 »
Hi Maciek,


Perhaps one (1) is the oxygen tank in the aft torpedo room that we could not find?


Regards,
Don_

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3656 on: 01 May , 2017, 08:50 »

Hi Don, Maciek and all others.
I am finally back on the net after an eventful openening of my summerfarm. Putting an old  farm in the freezer for the winter require precautions and a lot of actions based on years experience.The trouble being an old man however is  your require some help to do the job and with helpful grandchildren, we thought we managed last year.Unforntunately not so, and we had a few frostbursted pipes, iceblockage of the water main supplypipe and quite a few other things as well, however now it seems everything is back to normal and we are on the net, touch wood! I see there are still a number of questions and I shall try attend as soon as possible. I guess the  starting air vessel for the Junker is as on my image below. The oxygenflask at the bottom stb boardside is found and as far as I know the Junker exhaustpipe and internal valve is removed due to the accessdoor made in the pressurehull of U 995. The further arrangement have to be guesswork and I shall revert with some proposals in a while.
Tore
« Last Edit: 01 May , 2017, 08:54 by tore »

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3657 on: 01 May , 2017, 14:15 »
Hello Mr. Tore,


Glad to see you're back online...  You answered a lot of my questions about the country farm home, and I guess all the preparations my men and mice can not foresee all the obstacles created by mother nature.  It's great to have help from your grandsons...


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3658 on: 02 May , 2017, 08:37 »
Don.
As far as I can see the Junker exhaustsystem has been of considerable consern and changes since it was introduced. The two stroke, opposed piston engine was susceptible to exhaustgas counter pressure and carbonisation due to the ballancing of the free pistons and I guess there are a number of executions as the developement occurred. Again we don`t have much drawings available thus we have to assume some of the solutions based on photografic images. Below is my proposal of the plain exhaustsystem were cooling piping and casing are omitted as well as the intricate interlocks and the grindingsystem. To prevent waterintrusion in the Junker through the scavenging ports which are open in the starting position is of course of paramount importance, hence the watertrap and drainage is placed at the lowest point just before the Junker. The starting procedure would be as follows: The opposed pistons are cranked in the outer starting position, the stern buoyancytank vent is shut, allowing the outer exhaustvalve to be opened, however prior to opening the valve, LP air is admitted to the space between the inner and outer shut exhaustvalves. When opening the outer exhaustvalve the airpressure is forcing the possible water into the silencer and overboard whereupon the inner exhaustvalve is opened, and possible residue water is drained at the waterseparator and the Junker can be started. I guess the extra exhaustvalve after the boardvalve on the old plan would not be nessecary with the assumed U 995 execution. Unfortunately both the boardvalve,drainage, watertrap and most of the exhaustpiping is removed on the U 995 presumeably to make visitors access through the door in the pressurehull .
Tore
« Last Edit: 02 May , 2017, 09:01 by tore »

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3659 on: 02 May , 2017, 22:56 »
Hello Mr. Tore,


Is the aft buoyancy tank venting hand-wheel located on the upper pressure hull (between the 6th and 7th frame port side) in back and above the e-compressor.  I don't see how the lever with the interlock segment connects to the aft buoyancy tank or the hand-wheel?


Maciek had provided an image that showed the aft buoyancy venting valve hand-wheel located between the 6th and 7th frame, and the hand-wheel for blowing the aft buoyancy tank with LP air located between the 7th and 8th frame.


I also noticed there is a step in back of the e-compressor for the crewman to reach these valve hand-wheels.


Regards,
Don_
« Last Edit: 02 May , 2017, 23:25 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3660 on: 05 May , 2017, 13:53 »
Don.
I have checked the pages in Your Skizzenbuch as requested and have following remarks.
Page 72.....Reason-to maintan the u boats correct buoyancy..... With such small amount of fueltransfer mentioned there is hardly any changes in the submarines buoyancy,or, the difference in weight between fuel and seawater is roughly 0.15 kg pr. kg water and if you only top up the day tank of say 175 kgs this means some 25-30 kgs weight difference. Apart from pressurerizing the internal fueltanks, one of the main advantages of the compensating water is to reduce the surface effect of a partly filled tank by keeping the tank full all the time.

Page 85..... normally it is the engineroom staff checking the compensatingwater when fuelling, not the depot personell.

Page 97-99  I Guess we should need a bit more Research on the Junker exhaustsystem as it is currently too many loose ends.

Page 108-109  I believe you have to vent the buoyancy tanks at any diving as otherwise shall introduce fairly large tanks with considerable variable buoyancy and free surface effect. I assume replacing the venthandle ( Wheel) from fore torpedoroom to the controlroom was a consequence of the alleys air superiority in 1943, increasing the need for crashdiving and a quick control of the bow down diving in the controlroom.
The Atlantic bow was introduced as you say in 1943 to improve the surface condition of the submarine by reducing the longitudenal pitching. I don`t think the wider beam bow is describing the Atlantic bow, rather a flare bow.

I guess the buoyancy tanks might influence the submerged condition if not vented. The air volume of the bow boyancy tank at 50 meter is compressed from appr. 8m3 at the surface to 1,33 m3. Which means theoretically a loss of 6,67 m3 displacement at the bow and 3,567 m3 at the stern. A total displacement loss of 10.237 which has to be compensated. Generally you want to avoid large displacement variations by having easy compressible gases (air) taking part in the descend. In this case of not venting the buoyancy tanks you would have to compensate for the loss of displacement by pumping out some 10.000 liters regulating waters whereas to compensate for the total pressurehull compression you need only 500 liters. Of course the temperature influence the calculation, but assuming the cooling effect of the lower temperatures at 50 meters would compensate for the compression temperatures. At 50 meters the compression of the airdisplacement in the bow and stern buoyancy tanks would upset the buoyancy and the trim of the submarine as well as introducing an undisireable surface effect.

Page 125-126. The aux coolingwater pump.... is located on the fore bulkhead port side... stb side.

Page 143 Using the other engines lubeoil pump is possible, but not the first choice. It is far easier and quicker to use the electrically driven aux. lubeoilpump by that you are able to use both systemtanks.

Page 144-145 As discussed earlier, the easiest way to transfer fuel from the submarines fueltanks is by submitting compensating water under pressure to the tanks. The aux.fuel tranfer pump is primarily used for draw fuel from another source (submarine?) to the fuel storage tanks.
Luboil hand pump. Normally the electric driven aux. pump was running before starting or turning the engines. The luboil handpump was as you say mainly used for maintenance jobs as well as for topping up the systemoil by fresh oil from the storagetanks.
Page 148. In the event of a failed luboilpump my first choice would be to use the electrically driven aux.lubeoil pump in stead of hooking up to the other engines luboil pump.
Page 429 Transfering fuel from inboard tanks to saddletanks. I am not familiar with not using the internal fueltanks and not cracking the while schnorcheling and not cracking the compensating water board valve. The reasoning that the engineroom gravety tank ( daytank) might be based on a misunderstanding as this tank is an open tank with 6 overflow pipes. May be you are refering to the interanal storagetanks?
The transfering of fuel from the inboard tanks to the saddletanks is a bit complicated to me as by pumping out fuel without watercompensating you introduce a fairly heavy surface effect in the large fueloil storage tanks during schnorcheling which you absolutely do not want. If you neverteheless should choose to pump fuel from th inboard fuel tank to the saddle tank you could just as well pump it to the gravety tank in the engine room.
« Last Edit: 05 May , 2017, 13:59 by tore »

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3661 on: 05 May , 2017, 22:23 »
Hello Mr. Tore,


Thank you for reviewing the many pages...


Page 72 - I was attempting to get across that compensating water always had to replace the fuel oil forced into the day tank.  Eventually, the internal tank would be half empty; in other words half fuel oil and half compensation water.  Possibly the U-Boat would not be able to dive if the internal tanks were half fuel oil and no compensating water.  Was my attempt too awkward?


Page 85 - I changed form "depot personnel" to "engine room personnel" in two places on that page...


Pages 97-99 - I agree...


Pages 108-109 - I changed the word "wide beam bow" to "flared bow"


Type VII C/41
surfaced displaces 759 tons
submerged displaces 865 tons
increased displacement when submerged 106 tons


This is the displacement (106 tons) from anything above the water line; pressure hull, tower/bridge, deck and casing, cannon, etc. I don't believe there is any weight gain by flooding the ballast tanks, just a loss in buoyancy because of venting the air volume in the ballast tanks.


Therefore, when the U-Boat dives and doesn't vent the buoyancy tanks, the air is compressed with depth to a greater extent and has little effect on buoyancy the deeper the U-Boat dives, but the water displacement gain in the buoyancy tanks does not need to be compensated for by pumping water from R1 or R2.


Where have I gone wrong again? I don't believe we need to counter the water weight in the flooded ballast tanks...


Pages 125 - 126 That was a dumb error, I had it correct on the drawing...


Page 143 - I added another line to the page with your sentence...


Page 148 - I think page 143 may be sufficient... What do you think?


Page 429 was taken from a U-Boat KBT from the uboararchive.net web site...

Note - the attached drawing seems to indicate there was the ability to hand pump the dirty oil tank contents overboard into the sea.  The current U-995 only has that short pipe with an end cap. That looks modified or wrong to me?

Kind regards,
Don_
« Last Edit: 05 May , 2017, 22:26 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3662 on: 06 May , 2017, 08:01 »
Don.
The displaced water of a surfaced submarine is equal to the total weight of the submarine including equipment and crew. This displacement creates a positive buoyancy which makes the submarine float at required draft adjusted by the regulating tanks.
As a submerged submarine displaces the superstructure with pressurecontainers, ducts etc., above the surface waterline in addition to the surface weight deplacement, the submerged displacement of a submarine is larger than the surface displacement. This submerged displacement consist of components with variable compressabilities of which the gases (air) has the highest and steel the lowest. For a VIIC the pressurehull compression would be about 100liter per. 10 m, steel and other solid practical nil and possible air in tanks connected to the sea according to Boyle Mariottes Law: P1V1/T1=P2V2/T2.
As the submarines ballast tanks are vented, the displacement air is substituted by seawater and the displacement caused by the air is removed. The buoyancy created by this displacement is gone causing he submarine to have a passive descent if the regulating tanks are adjusted to a weight slightly larger than that of the deplacement loss.
During the descent the ambient waterpressure increases and a  compression of the compressable components start. As a consequence the submerged displacement decreases. This has to be compensated by discharging an equal amount of regulatingwater .
The pressurehull compression at 50m depth has to be compensated by 50 l.and a possible non vented bow buoyancytank of 8m3 would get an air compression to some 1.33m3 which means 6,67m3 less than the sealevel volume, thus the displacement of that tank would result in a buoyancy loss of 6,76m3 which has to be compensated to maintain the required buoyancy at a given depth. The easiest way to avoid such correction would be to vent the bow and stern buoyancytanks when diving and let the tank act as a freeflood area.
Tore
« Last Edit: 06 May , 2017, 08:06 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3663 on: 06 May , 2017, 20:03 »
Hello Mr. Tore,


Thank you for the info about displacement when diving the type VII U-Boat...


"possible non vented bow buoyancy tank of 8m3 would get an air compression to some 1.33m3 which means 6,67m3 less than the sea level volume, thus the displacement of that tank would result in a buoyancy loss of 6,76m3 which has to be compensated to maintain the required buoyancy at a given depth."


The bow and aft buoyancy tanks are above or at the waterline when the U-Boat is running on the surface... Therefore, the weight of these empty tanks (except for air) is compensated for at the U-Boat's waterline.  In a non-emergency dive the non-vented buoyancy tanks only present an air pocket which will slightly inhibit the U-Boat's diving rate, but as depth increases the air pocket is compresses and the overall diving resistance becomes nil at greater depths.


I don't see a buoyancy loss where any compensation is required in this scenario for the buoyancy tanks...


In an emergency dive the buoyancy tanks may be vented to eliminate the air pocket resisting the diving rate.


I apologize for my constant doubts, but I would like to fully understand this diving process.


Regards,
Don_


PS - This post of mine is numbered 666 - I guess the Devil is in the details... Ha ha!
« Last Edit: 06 May , 2017, 20:07 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3664 on: 06 May , 2017, 23:44 »


Don.
I guess we  talk about Archimedes in this case and variable displacements and buoyancy: a body immersed in a fluid partly or wholly is boyed up by a force equal the weight of the fluid displaced by the body.  Just below the surface the volume of a not vented bow buoyancy tank displaces 8m3,  hence the submarine is buoyed up by a force equal to the weight of 8m3 seawater. As the air trapped in the tank is substantially compressed at 50 m depth to some 1.33 m3, the buoyancy force is still equal to the weight of the displaced seawater, however the displaced sea water, practically not compressible, is now decreased to 6.67m3 hence the buoyancyforce of the tank is 8-1,33= 6.67m3 less. The same happens to the pressurehull which is far less compressible than the trapped air in the buoyancy tanks. You can`t use Boyle Mariottes Law on the pressurehull, but an experience figure says the pressurehull is compressed by 100 l. per 10 meter diving depth corresponding to 500 l at 50m depth. As for the increased displacement due to the superstructure, the displacement changes are practically nil because it is not compressible as long as you don`t have airpocket trapped somewhere.
The basic for a submarines passive changing of diving depth  is changing the buoyancy force, diving by reducing the displacement (buoyancyforce) by venting the ballast tanks and surfacing by increasing the  displacement(buoyancy force) emptying the ballasttanks.  The buoyancy tanks are not listed as ballast tanks and do not participate in such diving procedure thus should be vented at the surface prior to diving and considered as a  freeflood area when submerged. to overcome the surface "resistance" you should use the Q tanks (Untertriebzelles).

Tore
« Last Edit: 07 May , 2017, 08:53 by tore »

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3665 on: 07 May , 2017, 01:37 »
Being practically fully installed in my summerfarm, I have been able to pickup my painting hobby and brushed up my old painting of KNM Kaura ex U 995 on an immaginary crossing of the westfiord in Northern Norway around 1953. The old steamer in the background is the "expressship" S/s Finmarken southward bound wheraes the KNM Kaura is going north to the Barentz sea.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3666 on: 07 May , 2017, 20:23 »
Hello Mr. Tore,



"Just below the surface the volume of a not vented bow buoyancy tank displaces 8m3,  hence the submarine is buoyed up by a force equal to the weight of 8m3 seawater."


Yes! I understand that statement...


"As the air trapped in the tank is substantially compressed at 50 m depth to some 1.33 m3, the buoyancy force is still equal to the weight of the displaced seawater, however the displaced sea water, practically not compressible, is now decreased to 6.67m3 hence the buoyancy force of the tank is 8-1,33= 6.67m3 less."


The 2nd sentence seems to emphasis the negative...
So the U-Boat at 50 m is buoyed up by the force equal to the weight of 1.33 m3 seawater (The effective buoyance displacement was reduced with depth). The 8m3 bow buoyancy tank was never part of the displacement balancing equation (Not Part of the Ballast System). When the U-Boat is on the surface; there is no positive buoyancy created by the bow buoyancy tank because it is above the waterline. Hence no compensation was required especially for air...


I think we both agree with that statement (Yes/No)?


The weight of the U-Boat prior to the dive is the same at 50 meters, or at 200 meters... However, the displacement (Volume) may be less because of hull compression and some water may be pumped from the regulation tanks to compensate and balance the U-Boat.


THE BOTTOM LINE____


I could see the U-Boat taking in 1,330 liters of water at a depth of 50 meters to compensate for the air contents in the bow buoyancy tank. However, if the U-Boat went down to 200 meters depth, the they would need to pump out about 1,000 liters of water to balance. That would not be desirable in an emergency situation and required to use the batteries to pump out the excess weight.


From our previous discussions, the buoyancy tanks were not considered as part of the ballast system. Mr. Tore - do you know if your Karua crewmen utilized the buoyancy tanks during a dive? I would think (Given with my lack of expertise) that the buoyancy tanks were only vented during an emergency dive situation...


What do you think?


************ Your Latest painting *******************


Excellent work, the airbrushing really makes thing pop out from the canvas.  My wife's (Maureen) father (Johannes) took painting lessons after he retired and did water color paintings before they moved to the US. He passed away about 3 years ago at the age of 89, her mom just turned 90 and is in good health. Did you take any painting lessons? Again Excellent work my friend!!!


Do you mind if I just use your latest painting in Skizzenbuch?


Kind regards,
Don_
A man's got to know his limitations...
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Offline SG

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3667 on: 07 May , 2017, 21:58 »
Tore, the painting is great. Waves and sea are masterfully rendered. Congrats!

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3668 on: 08 May , 2017, 11:58 »

Don.
I guess a graphic could explain my ideas better that the poor wording, see below. I think we are in agreement with your first paragraph.

The weight of the submarine prior to the dive is the same at 50m or at 200m. I agree if you dont`t pump out any liquid or discard any objects from the submarine.
However the volume, displacement may be less because of hullcompression and some water may be pumped out of the regulating tanks to compensate. The water pumped out of the regulating tanks has no influence upon the volume/displacement but on the weight of the submarine, however if you blow out some water from the buoyancytanks it shall increase the submarines volume and thus the buoyancy of the submarine.
I could see the Uboat taking in 1.330 liters at a depth of 50 meters to compensate.
I assume you are referring to buoyancy tanks not vented. I guess you are missing a 0 here as at 50 m you have a total loss of buoyancy of 12,22m3- 1,33m3= 10,89m3  pluss the pressurehull compression 0,5m3 alltogether 11,39m3 water equal to 11.390 liters, a considerable amount of water to be pumped out against 50m.
At 200m the total regulating water which is required to be pumped out of the two regulating tanks would be some 15.200 liters to compensate for the aircompression in the buoyancy tanks if not vented. In case they are vented, nil. This is one of the main reason that the buoyancytanks should be vented prior to diving
The ballast tanks are normally not used for ballancing and trimcontrol. We use the regulatingtanks and the trimtanks as they are easier to control for such purposes. Again, a partly filled ballastank/ buoyancy tank create a fairly large free surface effect momentum. The regulating tanks are centrally placed and small length which minimize these unfavorable elements.
On the surface the buoyancy tanks have the vents shut, this is increasing the bow and stern buoyancy when the submarine is pitching, sometimes immersing the buoyancy tanks, hence together with the flared bow reducing the pitching which is the purpose for the tanks. At calm sea they have no function.


Re Graphic below.
If you don`t vent the buoyancy tanks submerged, the light blue area e.g. displacement becomes smaller as the seawater intrusion (dark blue) get larger( representing loss of buoyancy). A VIIC having a displacement variation between 6 and 11m3 not compensated would get trouble with the dynamic control of the submarine. Thus you have to compensate this decrease in buoyancy force by reducing the submarines weight, this is normally done by discharging regulatingwater by less extreme volumes..
On Kaura we kept normally the buoyancy tankvents shut at the surface and open as a routine in the divingpreparation.
In the event of a crash dive all the tankvents were opened including the Qs starting with the bow tanks.
 Both Q tanks corresponds to a buoyancy of 4m3. If the buoyancy tankvents were shut they would represent a buoyancy force of 12,22 -4= 8,22m3 displacement, a hopeless figure for crashdiving and destroying the normal exellent short divingtime of 30 seconds for a VIIC.
the buoyancy tanks were not only vented in emergency cases, but always when diving .
Tore
« Last Edit: 08 May , 2017, 12:05 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3669 on: 08 May , 2017, 16:14 »
Hello Mr. Tore,


I searched through the entire "German Diving Regulation Manual," and not once are the Aft or Bow Buoyancy tanks discussed. However, they do cover the Negative Buoyancy Tank...


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3670 on: 09 May , 2017, 01:28 »

Don.
The Germans did not use the wording tank or buoyancy for these tanks, they simply called it for what is was, watertight bow and watertight stern. Wasserdichte  bug and heck.
In the hand book for the uboatcommander you shall find the watertight bow and stern mentioned as per my enclosure. The English translation is a bit wierd trying to make german words english, but anyhow I guess it would explain that the germans did as we, leaving the buoyancy tank vents open submerged.
By the way I forgot to answer you question on my recent painting, of course you are free to used it in your Skizzenbuch. Allthough I am as old as your father in law was, going on 89, I never took any painting lessons.
Tore
« Last Edit: 09 May , 2017, 02:24 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3671 on: 09 May , 2017, 14:05 »
Hello Mr. Tore,


OK... So, If I understand the functionality of the bow ans stern buoyancy tanks, then the following statements are true.


1. Technically the bow and stern buoyancy tanks are not part of the ballast system because they are normally above the waterline and not affecting the U-Boat's overall displacement.


2. The bow buoyancy tank's primary function is to counter under cutting.


3. The stern buoyancy tank's primary functions are to assure the bow is in a down angle during a dive, and it's above the waterline for the Junker's air compressor operation.


4. Both the bow and stern buoyancy tanks are vented after a dive is initiated to eliminate the air pocket which will impact the decent rate slightly.


Comments?


Regards,
Don_
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Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3672 on: 10 May , 2017, 01:13 »
Don.
Buoyancy tanks. In reply to your last post.
1. Yes, in bad weather surfaced having vents shut they increase the bow displacement when pitching, submerged vented, they are neutral as any non compressible material.
2. Yes, and reduce pitching movements.
3 No, the primary function of the aft buoyancy tank is to reduce pitching and increase displacement( buoyancy) , surfaced in bad weather, to counter act flooding of the Junker exhaust pipe.
The bow down angle assistance at passive diving is executed by main ballast tank 1 which is vented a bit later than the other main ballast tanks. The total bow down angle is achieved by speed and hydroplanes, dynamic, and the main ballast tanks ,passive. Both buoyancy tanks do not participate as they are vented prior to the diving order.
4. Normally both buoyancy tanks do not have any airpockets submerged as they are vented. The vents are shut after they are drained on the surface. If the weather  is bad you might speed up the surface drainage by shutting the vents and blow the tanks by LP air.
Tore
« Last Edit: 10 May , 2017, 01:22 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3673 on: 10 May , 2017, 14:49 »
Hello Mr. Tore,
Hello Mr. Tore

I believe I read somewhere that the Junkers air compressor could be operational up to Sea State 5 - Wave height 2.5 to 4 meters, and swells moderate/long. I don't know if sea state 5 was the cut-off limit or was included in the operational zone?

Diesel Engine Starting

The second thing that became apparent to me was when you are starting either the GW or the MAN diesel engine with compressed air. According to the Diving Reg. Manual, the tail clutch should be dis-engaged and the clutch engaged between the diesel engine and the e-motor, so the e-motor can acts as a flywheel... Is this always the case when starting the diesel engine?

When running on starting air, at what rpm was fuel injected?
At what RPM do you engage the tail clutch to the prop?

How is the change over done when diving the U-Boat?

1. Do you shutdown the diesel, disengage the clutch between the diesel engine and the e-motor (both not running) and then start the e-motor to drive the prop?

OR -

2. Do you start the e-motor, then dis-engage the clutch (both running) to the diesel engine and then shutdown the diesel engine?

Conclusion - It looks like option #2 could be done in parallel with both diesel engines. While option #1 needs to be done serially because you don't want a sudden drop is speed.

When surfacing from a dive, what would be the diesel engine starting procedure?

3. Would you stop one e-motor, engage the Deisel/e-motor clutch and dis-engage the tail clutch to start the diesel engine, and then engage the tail clutch?

OR -

4. How???

Regards,
Don_
« Last Edit: 11 May , 2017, 00:10 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3674 on: 10 May , 2017, 23:25 »
Don.
I don`t believe you can put up accurately a sea state where you could not operate the Junker, it all depends on different circumstances like the trim, how you place the submarine in relation to the waves, the speed and course of the submarine etc.
The main engines were started both with the mainclutch engaged or disengaged as well as  with propeller engaged and disengaged. Of course when you were charging the batteries alongside  at the quay, you disconnected the propeller clutch. Before they removed the reversing of the diesels, the engines were started and stopped many times during maneuvring ahead and astern with propeller engaged.
The injection of the fuel during start was a matter of the engineers feeling and experience. I should think some 30-50 revs. depending how much massforces were engaged on the propellershaft.
You engaged the clutches preferably at stop, otherwise at the lowest possible revs. Again, it was depending on the massforces connected on the shaft. The higher the speed and massforces, the more wear and tear on the double cone clutches. If you engaged the mainclutch even at moderate revs, the friction forces created smoke from the friction layors.
Tore
« Last Edit: 11 May , 2017, 02:06 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3675 on: 11 May , 2017, 02:32 »
Hello Mr. Tore,


Thank you for the info...


One question


If during a dive and while on the surface, could you bring the diesel engines rpm down to 290, and at the same time fire up the e-motor to the maximum at 290 rpm, then could the main clutch be disengaged with out any friction or burning issues, or would there be a problem with mechanically disengaging a clutch while running (centrifugal force issues)? Perhaps the diesel engine would have a problem with suddenly no load? I guess that may kill that idea...


Just a thought...


Regards,
Don_
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Harry Callahan, SFPD

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3676 on: 11 May , 2017, 03:15 »
Don.
Disengaging the engine clutch did not create a problem with regard to the heating of the friction lining of the double cone mainclutch, but a sudden loss of load could be hard on the governor of the dieselengine and would probably need an engineer at the fuelhandle. I Guess such crash diving action was taken when attacked by plane during diesel surfacecruising. The real problem with switching in and out rotating masses on the shafting is the torsional vibrations creating very large stresses in the shaftings which might break crankshaft as well as propellershaft. The primary part of the mainclutch ( attached to the dieselengine) act as a flywheel running disconnected at normal load, but when you switch in the e-motor/generators and  disengaging the propeller, you introduce a different torsional vibration scenario, which again is changed  switcing in the propeller shaft ( propeller) and for a GW engine connecting the Roots blower at high outputs.
In the earliy stage before you calculated the torsinal vibration stresses in the shafting quite a few broken propellershfts and crankshaft occurred. This resulted in a thorough calulation and an installation of a torsional vibration damper on the front of the crankshaft " chopping " up the worst vibrations.
Tore
« Last Edit: 11 May , 2017, 03:26 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3677 on: 11 May , 2017, 23:47 »
Hello Mr. Tore,


Thank you for the last posting...


I have updated the following pages:


Prologue - pages XVI and XVIII - concerning the diving and surfacing sequence
Pages 108 - 109 - concerning the buoyancy tanks
Page - 414 - concerning an emergency/crash dive sequence


When you have time, would you please review and correct any problems?


At this point, I believe Skizzenbuch is in the final stage of being complete; unless, something comes up that is wrong and needs to be corrected. Everything I have added has been by making page lay-out changes and I haven't been adding any pages for several months because I don't want to have to re-index the entire book again. However, If something needs to be corrected, then I will do what ever is necessary.


I have uploaded the latest version of Skizzenbuch into my Dropbox account folder...


Regards,
Don_

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Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3678 on: 12 May , 2017, 00:31 »
Don.
I have scanned your new skizzenbuch only and shall revert if any remarks. I think your Skizzenbuch is a never ending project as you go into more and more details, hopefully it would be more interesting for the reader. I am busy with the Junker exhaust and I have a few new inputs coming up in a few days I hope. I don`t like our present "solution" very much, so I assume your text has to be revised.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3679 on: 12 May , 2017, 01:53 »
Hello Mr. Tore,


OK...  The only thing that must be considered with the Junkers internal exhaust valve mounted on the upper pressure hull is that it has to rotate the bottom external shaft segment and drive shaft extends to the upper segment which drives and intermediate segment (the interlock).  Also, it close/open the the grinding valve plate and position the intermediate segment so the lever may be enabled to lock or is disabled.  All of which must be accomplished by turning one hand-wheel...


That gearing ratio system was the only thing that I could come up with that would fit within the constraints of the outer casing.  Also, what does that 90 degree lever actually control when rotated or locked-out?


Kind Regards,
Don_
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Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3680 on: 12 May , 2017, 12:02 »
Hello Mr. Tore,


Is the Skizzenbuch 12-5-2017 PDF File that you uploaded to dropbox the file that you were going to modify?


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3681 on: 13 May , 2017, 00:21 »
Don.
I am sorry not being able to give you a quick answer on the Junker exhaustsystem, the reason being I am utterly confused as I can not remember the stern buoyancy venting system with interlocks  launched as a possible system for the venting of the stern buoyancy tank and exhaust valve of the Junker. I am afraid I have to switch to another assumption. In Bremerhaven is a  museum submarine of type XXI laying alonside afloat I have in fact seen it several times but not being onboard. This submarine was commissioned just at the end of the war and was never on war patrol. She was scuttled at the surrender but raised and recommissioned by the Bundesmarine in 1960 when Germany became a member of NATO and became the mother of the future modern submarines of the german navy as well as the Norwegian navy. Willem Bauer ex U 2540 was serving in the German Bundesnavy till 1980. Long story short, I stumbled over a photo of what looked exactly like our "Junker exhaustvalve and buoyancy ventingvalve" fitted aft in this XXI boat. To my astonishment the test stamping on the housing was in English and checking further I registered  this was an English design of a Bold ejector. My therory is that Nato has a standard type of decoy cannister used by Nato long after my time and the ejector was installed in U 995 after my time as a NATO standarization. Sorry I guess it is back to the drawingboard.
Tore
« Last Edit: 13 May , 2017, 00:40 by tore »

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3682 on: 13 May , 2017, 02:13 »
Hello Mr. Tore,


I don't believe that device is not a Bold device... It is an exhaust valve for the Junkers compressor.  I believe you can clearly see the exhaust pipe in the upper right corner. I have a Type XXI schematic print that shows 2 junkers compressors located in the aft area of section 3 where the 2 - 6 cylinder diesel engines are located. I will post copies of the Type XXI schematics later. Also, I see dates stamped in the one area that look to be 11 8 43, and tested to 1000 lbs???  I believe the current Type XXI has only 1 junkers and 1 battery powered compressor.


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3683 on: 13 May , 2017, 11:13 »
Hi Gentlemen,


Tore, great spotting. I like your theory very much.


Don, according to US Navy Report on type XXI U-Boat, this vessel was equipped with:
two Junkers compressors located in the aft part of the diesel engine room;
one electric compressor located in the pump room under the control room.


The "exhaust valve" visible on the photos provided by Tore is located in the aft room, on stb side:
https://www.flickr.com/photos/clemensv/9447842743/


I don't think that Germans led the exhaust duct from diesel engine room, through electric motor room, to the aft room.


I have attached photo of the original bold ejector installed in aft room (at stb side) of U 2518.
I think that post-war version of the ejector (as Tore suggested, of NATO standards) was installed in place of it.
It could be used as bold ejector as well as signaling flares ejector.


The question is, why Norwegians did not remove the Junkers compressor, when they decided to put the bold/flares ejector in place of the exhaust valve?


Generally, such post-war ejectors were called (at least in RN) Submerged Signal Ejectors.
Here you can find description of three types of ejectors: MK 2, MK 4 and MK 7:
https://maritime.org/doc/oberon/weapons/part2.htm
In my opinion, S.S.E. MK 4 is slightly similar to the arrangement found in aft room of U995 and U 2540.


At the bottom of the page, you will find some drawings of the "items" ejected from this device.


--
Regards
Maciek


Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3684 on: 13 May , 2017, 20:18 »
Hi Maciek,

Nice photo of the Type XXI's original "BOLD Device"...

OK.. I assumed wrong when I seen a photo of the e-compressor in the Type XXI. Now, I believe the current Wilhelm Bauer should have 3 air compressors; 2 Junkers and 1 electric. (see attached image 3372a)

I also don't believe the Germans ran the Junkers exhaust from the diesel room to the aft room because that makes no sense.

However, the photo c4834_o (attached) from the Wilhelm Bauer shows a Junkers exhaust valve in the aft section, in place of the original Bold ejector (your photo).  That looks to be dead wrong!


I believe that I understand everything you posted except the following:

"The question is, why Norwegians did not remove the Junkers compressor, when they decided to put the bold/flares ejector in place of the exhaust valve?"

At the beginning of your post you state that Tore's photo is of the exhaust valve (I think so).

1. The current bold ejector on U-995 above the Junkers compressor looks to be correct, and it matches up with the outer hull casing. Is this correct?

2. The current exhaust valve in the upper pressure hull looks to be original in U-995, but the junkers exhaust pipe was cut off. So we don't see the exhaust pipe to the water separator or the exhaust pipe from the separator Which should go to an exhaust hull valve (I think). Is this correct?


Regards,
Don_
« Last Edit: 13 May , 2017, 23:36 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3685 on: 13 May , 2017, 21:04 »
Type XXI Image


Don_
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Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3686 on: 13 May , 2017, 23:54 »

Hi Don,

However, the photo c4834_o (attached) from the Wilhelm Bauer shows a Junkers exhaust valve in the aft section, in place of the original Bold ejector (your photo).  That looks to be dead wrong!


No, I think (the same as Tore) that it is not a exhaust valve. In my opinion this is post-war ejector of bold/flares, installed in place of the war-time bold ejector.

What would be the reason to install the exhaust valve in the aft compartment, with no exhaust duct (from Junkers compressors in Diesel engine room) connected?

I believe that I understand everything you posted except the following:

"The question is, why Norwegians did not remove the Junkers compressor, when they decided to put the bold/flares ejector in place of the exhaust valve?"

At the beginning of your post you state that Tore's photo is of the exhaust valve (I think so).


In my post I put the exhaust valve in quotation marks, to indicate that this item (supposed to be a exhaust valve before) should be explained in different way.
I'm sorry, if it was not clear enough.


1. The current bold ejector on U-995 above the Junkers compressor looks to be correct, and it matches up with the outer hull casing. Is this correct?

Right. The question if this is original, war-time ejector or was it altered after war too.

2. The current exhaust valve in the upper pressure hull looks to be original in U-995, but the junkers exhaust pipe was cut off. So we don't see the exhaust pipe to the water separator or the exhaust pipe from the separator Which should go to an exhaust hull valve (I think). Is this correct?


I state, that in U 955, in the upper pressure hull is post-war bold/signal ejector (submerged signal ejector). It was installed in place of the Junkers compressor exhaust valve. So the exhaust pipe from the compressor had to be removed (as well as water separator).
My question was, why they did not removed Junkers compressor also. Without exhaust valve, exhaust pipe and water separator, the compressor was useless.


--
Regards
Maciek
« Last Edit: 13 May , 2017, 23:57 by SnakeDoc »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3687 on: 14 May , 2017, 00:55 »
Hello Maciek,


Let's tackle this issue one item at a time...


First - the original German Bold ejector is mounter on the pressure hull above the Junkers compressor, and it aligns with the external slot in the external hull casing. There is a hinge on the Bold so that when the ejector is opened internally an new cartridge may be inserted.


In back of the junkers compressor is the water separator which is the exact same separator that you Identified in the U-570 photo.


See image


Regards,
Don_

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Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3688 on: 14 May , 2017, 01:10 »

Hi Don,

First - the original German Bold ejector is mounter on the pressure hull above the Junkers compressor, and it aligns with the external slot in the external hull casing. There is a hinge on the Bold so that when the ejector is opened internally an new cartridge may be inserted.

Right, however I'm not 100% if it is original German design, or was it altered by Norwegians after war (the design is quite different than ejector from U 2518).

In back of the junkers compressor is the water separator which is the exact same separator that you Identified in the U-570 photo.


No, the marked item is not the same separator as on U 570 photo. This is water separator of the hp air system, see the drawing.


You can trace the line going to Junkers compressor (the last fragment missing) as well the line going to the electric compressor). It is also possible to trace the connection to the hp line (with strainer attached).


--
Regards
Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3689 on: 14 May , 2017, 01:32 »
Hi Maciek,


We do have a water separator on the exhaust...


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3690 on: 14 May , 2017, 01:43 »
We do have a water separator on the exhaust...


Of course, but the exhaust separator is NOT present on U 995. The connections of the separator on U 995 clearly show that this is water separator on output of the air compressors.


In other words, there should be two different water separators originally, but now, only one is present.

--
Regards
Maciek
« Last Edit: 14 May , 2017, 01:45 by SnakeDoc »

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3691 on: 14 May , 2017, 01:52 »
Hi Maciek,


Don't these photos look the same?


Regards,
Don_

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Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3692 on: 14 May , 2017, 01:59 »
Don't these photos look the same?
In my opinion, the exhaust separator on U 570 photo is closer to the boat's centerline, while the HP air separator on U 570 is just at the hull.
I think that there is some space visible between the hull and exhaust separator on U 570.


--
Regards
Maciek

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3693 on: 14 May , 2017, 02:05 »
Does this photo help with the space issue?
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Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3694 on: 14 May , 2017, 02:14 »
Does this photo help with the space issue?


Yes, this photo presents a little different angle view.
However, as I said before, the line connections suggest clearly that is HP compressed air separator.


--
Regards
Maciek

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3695 on: 14 May , 2017, 02:21 »
Hi Maciek,


The only thing that bothers me is that the Wilhelm Bauer Type XXI has that device in place of the original Bold. It does not in any way look like the SSE Mark 2 or the SSE Mark 4.


The device in U-995 does not look to have the ability to swing open like the Mark 2, nor does it have the ability to hinge open like the Mark 4 because of the pipe and the segment shaft to the interlock.


Mr. Tore cold resolve the question about the junkers compressor...
*********************************************************************
Mr. Tore - do you remember if the Junkers air compressor was ever used on U-995?
*********************************************************************


If the Junkers compressor was used by the Norwegians, then changes were made during the Museum renovation; But what changes?


See the 3 images for a comparison...


Regards,
Don_
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Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3696 on: 14 May , 2017, 08:44 »

Hi Don,

The only thing that bothers me is that the Wilhelm Bauer Type XXI has that device in place of the original Bold. It does not in any way look like the SSE Mark 2 or the SSE Mark 4.


In my opinion, in case of Wilhelm Bauer the matter is clear: the war-time bold ejector was replaced with post-war SSE. Where could they put the new ejector? In the place of the old one.


I didn't say that it looks like SSE MK 2 or MK 4, I said it looks slightly similar to the MK 4.


At first, in my opinion, the ejector on Wilhelm Bauer is the same type (or maybe not of the same type but the same design) as ejector installed in place of the Junkers exhaust valve on U 995.
Here is the comparison:





1. shaft (for opening the external flap)
2. gear for driving interlock (to prevent opening the internal flap when external flap is opened and vice-versa)
3. shaft for driving interlock
4. blanked connection
5. line connection for flooding/draining the ejector
6. the hinge
7. the shaft for opening internal flap




I'm not sure if you agree that these are the same devices or not?

The device in U-995 does not look to have the ability to swing open like the Mark 2, nor does it have the ability to hinge open like the Mark 4 because of the pipe and the segment shaft to the interlock.

OK, this is how it supposed to work (according to me, at least):
The shaft (1) driven by hand-lever is for opening the external flap. The flap is opening against the sea pressure.
The flap is interlocked (by means of the gear 2 and shaft 3) with internal flap, to prevent opening both flaps at the same time (similarly as in case of the torpedo tubes).
To open the external flap (with charge loaded into the ejector), the pressure inside the ejector has to be equalized with external sea pressure. Otherwise, the sea pressure forces the external flap (opening outwards) to be closed. The equalization is done by means of the line (5), which makes possible to flood the ejector with external sea water (similarly as in case of torpedo tubes).
When charge was ejected, the external flap is closed and the ejector can be drained by the same line (5).
The piping on U 995 is missing, however on Wilhelm Bauer the piping seems to be complete: there is visible line branching to small hull valve and the branch to drain/vent the ejector.

And the most important thing: how the internal flap was opened (to load anything into ejector)?


I think that internal flap (or breech) was opened similar to the S.S.E. MK 2, the breech was moved/slid aside horizontal (unlike the MK 4, where the breech is opening downward).





The hand-wheel can drive some kind of dog-catches (as in case of the normal hatches).

Mr. Tore cold resolve the question about the junkers compressor...
*********************************************************************
Mr. Tore - do you remember if the Junkers air compressor was ever used on U-995?
*********************************************************************


If the Junkers compressor was used by the Norwegians, then changes were made during the Museum renovation; But what changes?


The brief history of KMN Kaura:
01.12.1952 - commissioning in Royal Norwegian Navy
1957 - overhauling and modernization
12.1962 - putting into reserve


Removing of the Junkers exhaust could be done by Norwegians in 1957. They could use it before 1957 and could abandon using it after 1957. During the renovation/restoration to the state from May 1945 (in 1971) there would be no sense to install new ejector in place of the Junkers compressor exhaust valve.


In the book U 995 by Eckard Wetzel, on page 144 there is a small photo of the aft torpedo room, taken on 1965, when U 995 was moved to Kiel, before any restoration work. I think that on the photo the present arrangement is visible. I mean that the device in place of Junkers exhaust valve (I assume that it is S.S.E) was present there in 1965.
It supports the assumption that it was installed there during overhaul in 1957.


--
Regards
Maciek

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3697 on: 14 May , 2017, 17:33 »
Hi Maciek,


I am wrong...  It looks like you and Mr. Tore are correct!  When one has so much time invested in a theory, then it's hard to let go.


Please go to this web site and review the posts because it looks like the bold device in U-995 and Wilhelm Bauer is from a Klass 205 U-Boat.


http://www.forum-marinearchiv.de/smf/index.php?topic=13257.15


See the photos...
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3698 on: 14 May , 2017, 19:44 »
Hello Mr. Tore and Maciek,


The Bold in U-995 and the Wilhelm Bauer Type XXI may be a Dutch or German design because the original Bold cartridges were very short "like a can of beans" but the newer Bold devices ran a distance and did a burst of bubbles or an explosion (Bang). so they were most likely longer.


They replaced the original bold in the Type XXI (after the war), I don't understand why they didn't replace the Bold in U-995 (unless the older cartridges wouldn't fit or launch in the newer Bold, so they kept both).


FYI (Maciek) - according to documentation I read; they replaced the 2 junkers compressors with e-compressors post war on the Wilhelm Bauer.


Rergards,
Don_
« Last Edit: 14 May , 2017, 19:46 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3699 on: 15 May , 2017, 00:37 »
Don and Maciek.
Sorry on my place in the world remote in the Norwegian forrests I lost my internet connection for some 24 hours. I am back and can answer the easiest question first, we used the Junker in my time, but it was very nosiy and needed frequent overhauls like cleaning of carbon deposites from the diesel pistons to prevent unballance. We definitely preferred the E-compressor. After I left the Kaura she had a major overhaul and I guess they the installed quite a few gadgets like the balkongeraet, a few US electronic devices which I assume was related to submarine traffic detection/registration etc. I have only seen these devices by photos and can not comment further on that. It could very well be they removed the Junker. My point is, I fully support Macieks theory, after my time a lot has been changed on ex.U 995 since my time onboard was terminated in 1954.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3700 on: 15 May , 2017, 14:11 »

Hi Don,

I am wrong...  It looks like you and Mr. Tore are correct!  When one has so much time invested in a theory, then it's hard to let go.

Please go to this web site and review the posts because it looks like the bold device in U-995 and Wilhelm Bauer is from a Klass 205 U-Boat.

http://www.forum-marinearchiv.de/smf/index.php?topic=13257.15

See the photos...


Nice photos. Indeed, they were taken in the Klasse 205mod U-Boat. However, this ejector is a different type than the ejectors from Wilhelm Bauer and U 995. Generally, the shaft for opening the external flap is very close to the ejector tube (on Wilhelm Bauer and U 995 it is a little more distant from the tube, to accommodate the interlock gearing).
The interlock is realized in a different way: the handle of the shaft for opening the external flap is removable. It can be placed at the shaft (to open the flap) only when the breech doors are in close position.


By the way, I must correct myself:

1. shaft (for opening the external flap)
2. gear for driving interlock (to prevent opening the internal flap when external flap is opened and vice-versa)
3. shaft for driving interlock
4. blanked connection
5. line connection for flooding/draining the ejector
6. the hinge
7. the shaft for opening internal flap


Of course it should be:
2. gear interlock
3. shaft (driven by breech doors) for interlock


--
Regards
Maciek

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3701 on: 15 May , 2017, 19:31 »
Hello Mr. Tore and Maciek,


It looks like the aft torpedo room in U-995 is presently in a modified state where the Junkers compressor was not usable because of the removal of the junkers exhaust system. If the junkers compressor were usable, then the setup would be similar to the one as seen in U-570.


They installed a different version of the bold launcher in U-995. Do we know if there was an issue with the newer bold decoys and the older bold launcher. I don't believe there is an issue of horizontal launch Vs vertical because the Wilhelm Bauer does a horizontal launch.


I will search the internet to see if I can find a layout for the junkers compressor in a type VII...


Regards,
Don_
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3702 on: 19 May , 2017, 18:25 »
Hi Maciek,


Can you copy the photo form the U 995 book.. Or do you have another of the same era?
On the Bold device, I see how it gets flooded and drained, but how does the internal canister get launched?
On the Old Bold Launcher it looks like a piston on a guide/limit shaft was used and driven by compressed air?

Regards,
Don_.
« Last Edit: 19 May , 2017, 23:56 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3703 on: 22 May , 2017, 01:04 »
Hello Mr. Tore,


I believe that U-995 (Kaura) a Type VII C/41 had the same aft torpedo room Junkers exhaust configuration as U-570 a Type VII C. Then in 1957 the modernization disabled the Junkers compressor and they installed the second Bold Ejector.


I understand the functionality of the original side launch ejector with the piston and the attached long rod to create the end point for ejection.  This is the same design as the torpedo launch piston groves which only allow the piston to travel so far down the tube.


I don't quite fully understand the functionality of the vertical launch ejector because it does not have the original launchers piston with a capture rod which also prevented the launchers gases from escaping to the surface and giving up the U-Boat's location.


Since this device was installed in 1957 (Peacetime), could it be that they just use compressed air to launch a distress signal and they really don't care about the launch gases reaching the surface?


At this point, I really don't think it matters because the 1957 renovation and modernization was never part of the original German wartime U-Boat Type VII C, or the Type VII C/41!

Regards,
Don_
« Last Edit: 22 May , 2017, 22:06 by Don Prince »
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3704 on: 23 May , 2017, 00:28 »
Hello Mr. Tore, Maciek, and All,


I have updated Skizzenbuch and placed the latest version into my Dropbox folder...  I decided only to cover fully the Original German WWII version of the BOLD ejector, and not the version that was installed into U-995 (Kaura) in 1957. Besides, the air and drain lines have been cut-off so we can't see where they went and to what they are connected to, so it would only be guessing on our part. I don't want guesses in Skizzenbuch, only the facts and correct information...


Kind Regards,
Don
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Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3705 on: 23 May , 2017, 00:54 »
Hi Don,


regarding the post-war ejector: I think we should use term 'signal ejector' (as in the Oberon type sub manual) instead of 'bold ejector'. The signal ejector was used to indicate the position of submarine by means of flare (at parachute) or smoke. So ejecting the cartidge by means of compressed air was the simplest way, and the air bubbles appearing on surface were not a problem.


I think that in those times submariners did realize that Bold (being a active sonar counter-measure) was obsolete, because cold war was dominated by passive hydrophone arrays.


The Bold type counter-measures were later developed into torpedo decoys.


--
Regards
Maciek

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3706 on: 23 May , 2017, 02:19 »
Hi Maciek,


I agree...  It looks like they took the bold ejector like the one that was installed into the Wilhelm Bauer Type XXI and modified it for the use as an emergency signal ejector, and they don't bother to capture the launching compressed air.


Regards,
Don_


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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3707 on: 23 May , 2017, 02:56 »

Don
I guess Maciek got it right.  During my submarine training ( early 1953) the device was only briefly mentioned and named SSE (submarine signal ejector) and as far as I remember not installed in RN submarines before the new O class which in my time was on the drawing board and very hush,hush. We only learned about a "bubble decoy" which as far as I remember was like a small torpedo containing magnesia pellets generating air bubbles in contact with sea water. I guess it was launched like a torpedo. The pillenwerfer launched up to 4-5 cannisters of 10 cm diameter simultaneously resembling pills in a row hence, pillenwerfer. In my time (peacetime) we used the ejector for Veris flares to indicate torpedo firing during exercises and was handled by the torpedopeople. I think in the beginning (my time) the ejection was done by air not bothering by the bubbles. Today the SSE is developed to a complex device by the Nato navies which are totally different from the pillenwerfer. I don`t think the todays SSE has anything to do in a Skizzenbuch for the VIIC.


Tore
« Last Edit: 23 May , 2017, 03:24 by tore »

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3708 on: 23 May , 2017, 16:53 »
Hello Mr. Tore, Maciek, and All,


I updated Skizzenbuch with the info about our final discussions concerning the "Ejector" for emergency signals in U-995's aft torpedo room upper hull.


MY latest version of Skizzenbuch is in my Dropbox folder...


Regards,
Don_
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Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3709 on: 23 May , 2017, 23:20 »
Hi Don,
excuse me for the request: can you post the link to your Dropbox folder ? Is it available to anyone ? ( I never used Dropbox, and so I'm not very versed on it...).
Thanks in advance.
Filippo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3710 on: 24 May , 2017, 03:12 »
Hello Filippo,


"Skizzenbuch: U-Boat Type VII C Project" has not been finalized yet and I rely on Mr. Tore and Maciej to proof read the book and provide corrections and suggestions. However, I can state that it is very close to finalization...


Skizzenbuch: U-Boat Type VII C Project - 503 pages in an 11 x 17 inch format with an Appendix of 7 large pull-out document/schematic sheets


I had a contract with Schiffer Publishing to print the book, but they backed out in January of this year. If I end up with no publisher, or no internet sponsor, then I will purchase software to copy protect the Skizzenbuch PDF file from any unauthorized changes, and also an LLC to protect me. At that point, I may provide a copy protected file with an embedded reader to many of the U-Boat websites for distribution, including this one.


Maciej Florek has translated many U-Boat related manuals and documents for years, and we all have had the great fortune to see and download his excellent work.


Also, Dougie Martindale has provided U-Boat docmentation on the interned for years for us to enjoy, and I understand that Dougie is working on a book that he would like to see published. I believe his chances are excellent because of his knowledge on the subject, and it would be in a publisher's standard book size format.


Kind Regards,
Don
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3711 on: 24 May , 2017, 03:19 »
Hi Maciej,


I must apologize... Ever since you translated my U-Boat Type VII C manual for the uboatarchive.net, I have been typing your first name as Maciek like it was written above the manual credits. I have been wrong all these years and you didn't correct me?


I guess my first name would be Dumb and not Don?


I will need to make this correction is Skizzenbuch...


Kind regards,
Don_
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Harry Callahan, SFPD

Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3712 on: 24 May , 2017, 04:03 »
Thanks Don,
I did'nt knew anything of what you told, and I heard now the ( right ) intention of publishing all thing in a book.
Obviously, I'm really interested to buy that book, or the PDF files if it will not possible to print a book.
I'm looking forward to see any news about that...
Thanks.
Filippo

Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3713 on: 24 May , 2017, 08:32 »
Hi Don,


your first name is absolutely Don.


My first name officially is Maciej (used in documents and so on). However, the other form (maybe not diminutive, because it is not shorter) is Maciek, used by family and friends (because all you guys from this forum I consider as friends).


--
Regards
Maciek

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3714 on: 24 May , 2017, 13:28 »
Hi Maciek (My Friend),


I will not change the spelling of your first name in Skizzenbuck, unless you would prefer the Official Document spelling. It's not a big deal to make that change, I just a search and replace in 5 of the word documents and then join the 9 PDF files to create the Skizzenbuck 11 x 17 - M + I.PDF file.


Regards,
Don_



A man's got to know his limitations...
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3715 on: 31 May , 2017, 19:49 »
Hello Mr. Tore and All,


Maciek provided me with a photo of U-995 taken in 1965.  There is no Junkers air compressor in the aft torpedo room, and the emergency signal ejector is installed in the upper pressure hull...  Therefore, when the Germans restored U-995, they installed a Junkers air compressor, but I don't believe there is an exhaust or HP air connection.


Regards,
Don_
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Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3716 on: 01 Jun , 2017, 02:46 »
Don.
I guess this confirms our assumption. Somehow after 1955 the Junker was removed. In 1953- 1954 for sure the Junker was in place although not very frequently in use. As far as I remember we had to clean the dieselpistons every 75 hours due to carbonization causing unballance vibrations, no wonder they removed it.
Tore

Offline SnakeDoc

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3717 on: 01 Jun , 2017, 08:33 »
Hi Don,

maybe you will find this photo interesting. It presents loading torpedo to the aft torpedo tube of U 564.
The Junkers compressor, as well as part of exhaust duct and two exhaust valves are visible.

--
Regards
Maciek

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3718 on: 01 Jun , 2017, 09:19 »
Hi Maciek.
Interesting photos it looks as if they used the pressurehull opening for the Junker outer  exhaustvalve for the SSE.

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3719 on: 02 Jun , 2017, 15:43 »
Hi Mr. Tore and Maciek,


I added the images to Skizzenbuch page 98 and the latest in in Dropbox...


Regards,
Don_
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3720 on: 02 Jun , 2017, 23:59 »
Don.
I am afraid I have lost the general view of the pages I should check as it has been so many changes, is it possible for you to give a survey over which pages in your Skizzenbuch you want me to check?
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3721 on: 03 Jun , 2017, 01:21 »
Hello Mr Tore,


I believe we are current on pages to be verified...  Your post number seems to be stuck at 2,249??? and mine is stuck at 697???  I have just updated page 98, 99, 464, 465, and 466 and I am going to update Dropbox in about 10 minutes.


I do have one question...


Which spelling is correct?


Reinhard "Teddi" Suhren


- OR -


Reinhard "Teddy" Suhren


I see both spellings for Teddi - Teddy on the internet?


Regards,
Don_
« Last Edit: 03 Jun , 2017, 01:35 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3722 on: 03 Jun , 2017, 01:28 »
Hello Mr. Tore,


The latest version of Skizzenbuch is now uploaded into my Dropbox folder...


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline falo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3723 on: 04 Jun , 2017, 04:34 »
Hi Don,


the correct spelling is "Teddy".


I have read his autobiography "Nasses Eichenlaub", according to his own memories he was nicknamed "Teddy" because of the flabby kind he walks.


Regards
Falo

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3724 on: 09 Jun , 2017, 15:44 »
Hello Mr. Tore,


There is a Index.pdf file in the Dropbox folder... Is this some corrections?


Regards,
Don_
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Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3725 on: 10 Jun , 2017, 00:10 »
Don.
Sorry Don, I guess it was accidential put there by me in my effort to get to get a picture of which pages I need to check. Just a proof of that I am really not belonging to the IT generation. I am gradually starting to read the complete Skizzenbuch and I am afraid it shall take some time before I am through the book in this rural remote area of the world. I shall keep sending my comments as I read the book, but right now I got a message that my connection is reduced to 64 bits / sec.
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3726 on: 06 Jul , 2017, 19:02 »
Hello Mr. Tore, Maciek, and All,


I uploaded the latest version of Skizzenbuch into my Dropbox folder yesterday.  I corrected a spelling error in a graphic on page 390 "DESIGN"...  The word spell checker would not find that error in a graphic JPG!  I also changed any reference to myself as the author and replaced it with Managing Editor.


Two reasons:
1. You all provided the information in Skizzenbuch and I just rearranged the words and graphics to follow a readable format. You all contributed to my education and knowledge about the Type VII U-Boat and I am eternally grateful.
2. It may take me awhile before I distribute Skizzenbuch to all at no cost as an educational resource... I must establish an LLC for "Krystall Klare Publishing" and then Copyright "Skizzenbuch as a Multiple Source Book" and finally purchase "CopySafe Software" to protect Skizzenbuch from any unauthorized changes or modifications to the released form.


This will cost me a little over $500 USD; It's amazing that you must follow this procedure just to give away a book/document. I believe I may be able to get all this done later this year, or sometime early next year.


Therefore, we all still have time to make changes to Skizzenbuch until I get it copyrighted...


Kind regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3727 on: 07 Jul , 2017, 02:57 »

Don.
This answered my latest question which mean I can proofread your final Skizzenbuch. I shall start reading but I am afraid it shall take some time depending how many rainy days we get during the summerholydays of my children and grandchildren. I particulary liked you changed name on your publishing company and shall revert if I have some comments to your Skizzenbuch. Sorry you encountered so much trouble for you enthusiastic work.
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3728 on: 08 Jul , 2017, 19:35 »
Hello Mr. Tore,


I had to correct page 356 because the top photo and paragraph was wrong! This still had the old info about the signaling device being the Junkers exhaust valve and lever.


I uploaded a corrected version of Skizzenbuch in the Dropbox folder...


Regards,
Don_
« Last Edit: 11 Jul , 2017, 01:01 by Don Prince »
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Offline VIC20

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3729 on: 22 Jul , 2017, 16:51 »
… "Krystall Klare Publishing“ …


Do you mean kristallklar? Or is that a kind of play of words?

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3730 on: 22 Jul , 2017, 22:00 »
Hi Mark,


I didn't mean it to be a play on words... 
What should it be correct for Kxxxxxxx (German) Publishing (English)?


Krystall Klare
Kristall Klare
Kristallkar


I ran all 3 through my German Translator and they all come out the same; Crystal Clear???  I wanted Crystal Clear (to be in German) + Publishing..


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline VIC20

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3731 on: 23 Jul , 2017, 00:13 »
Kristallklar Publishing would be perfect. (It would be a good name too)

Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3732 on: 23 Jul , 2017, 12:25 »
Hi guys, when it's expected the publishing of your book ? I'm looking forward to buy it....

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3733 on: 23 Jul , 2017, 13:51 »
Hello All,


[The Bad News]
I had a committed publisher who cancelled about a month before the printing date.  Their reason for the cancellation was that they perceived the book was too expensive to print in a possible 11 x 17 format (about 500 pages) and the readership audience is too small and specialized to meet their required profit margin. Also, there are over 700 images (photos and drawings) which are mostly in color.


[The Good News]
Late this year, or early next year, I will get an LLC for "Kristallklar Publishing" and have the book Copyrighted, and purchase CopySafe software to encrypt "Skizzenbuch: U-Boat Type VII C Project" and the "Appendix Image Folder"... Once this is done, then the book may be downloaded as a viewable and printable file.


[The Best News]
I have spent the last 3 years learning about the Type VII C U-Boat from my great collaborators/friends on this web site. This is justifiably their book; I'm just the editor who assembled the information! We now have some time to review Skizzenbuch and assure to our best efforts that all the contents are 100% accurate.


Once all my milestones are met, then I will make the downloadable book file "Skizzenbuch: U-Boat Type VII C Project" available. I still have to work things out as far as distribution on several Websites, and I don't believe there will be any cost to the reader...  Free!!!


Kind regards,
Don_
« Last Edit: 23 Jul , 2017, 14:16 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3734 on: 23 Jul , 2017, 14:12 »
Hello Mr. Tore, Maciek, Simon, and Mark,


I corrected the publishing name to "Kristallklar Publishing, LLC USA" and that was the only change I made to the latest uploaded version of Skizzenbuch.


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3735 on: 24 Jul , 2017, 00:43 »
Hi Don,
excellent news....
I would like to have a classic paper book, but a free download printable file is maybe better, mostly in this economic crisis with few money circulating.....
Let us informed about the date of extimated availability of the file.
Respect to you and to all the book's authors....
Filippo

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3736 on: 29 Jul , 2017, 00:41 »
Hello Mr. Tore and All,

Dougie Martindale has provide me with some historical Info where I had incorrect info for several U-Boat photos.

I made corrections to the following pages:

127, 151, 170, 181, 210, 378, 440, and 446.

Also, Dougie has graciously said he would create replacement maps for pages 436 and 437. I may have a legal issue using Google Maps.

I still have an open issue on page 210 - The pitot tubes were underneath the bow torpedo tubes up through the U-Boat Type VII B. They were moved form underneath the bow torpedo tubes on the U-Boat Type VII C and beyond. The only issue I have is; where were the pitot tube/tubes located on the Type VII C U-Boat? Obviously, they must be below the waterline, and I can visualize - If a U-Boat Type VII B is sitting on the bottom, then the pitot tubes could get damaged, or plugged with debris (thus a good reason for the relocation).

Regards,
Don_
« Last Edit: 29 Jul , 2017, 00:54 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3737 on: 29 Jul , 2017, 02:10 »
Hello Mr. Tore and All,

I just uploaded the latest version of Skizzenbuch into my Dropbox folder...

Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3738 on: 30 Jul , 2017, 23:49 »
Hi Filippo,


Dougie Martindale has written the following:
http://amp.rokket.biz/docs/u-boat_colours_with_photos_5.pdf

U552 netcutters were removed between March and April 1941. For an accurate info to modellers about Type VII modifcations: [amp.rokket.biz] scroll down to "U-BOATS: Type VII Modifications" an awesome work by Dougie Martindale


Plus,
http://u-552.blogspot.com/2008/07/outside-of-ct.html


I hope this helps...  Skizzenbuck doesn't get into the details about specific U-Boats. I attempt to explain how everything works internally and externally.


Regards,
Don_



A man's got to know his limitations...
Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3739 on: 05 Aug , 2017, 20:08 »
Hello Mr. Tore and All,


It is my sad duty to inform you all that I have received an email this morning from Maciek Florek's wife, Olga Florek, that he had recently passed away. I will truly miss my very dear friend. However, a friendship is forever, so I look forward to seeing Maciek later!


Kind regards,
Don_




A man's got to know his limitations...
Harry Callahan, SFPD

Offline VIC20

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3740 on: 05 Aug , 2017, 20:12 »
I’m really shocked. He was such a great Uboat enthusiast with awesome projects. He was one of those I hoped to work with in the future.
« Last Edit: 05 Aug , 2017, 20:22 by VIC20 »

Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3741 on: 05 Aug , 2017, 23:12 »
Hi Don, if the file is available in your Dropbox folder, how can I have access to it ? Or it is still in preparation and not available for download ?

Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3742 on: 06 Aug , 2017, 01:29 »
Hi all, I realized now the content of the message about Maciek: I didn't know him, but I'm so sad for the lost of an U-Boat enthusiast.....

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3743 on: 06 Aug , 2017, 07:28 »
Hello Mr. Tore and All,


It is my sad duty to inform you all that I have received an email this morning from Maciek Florek's wife, Olga Florek, that he had recently passed away. I will truly miss my very dear friend. However, a friendship is forever, so I look forward to seeing Maciek later!


Kind regards,
Don_





Very sorry to learn the bad news, Maciek was a man of great VIIC knowledges, yet very modest in promoting his theories. It was a pleasure getting to know him and exchanging ideas as well as theories on the VIICs. Maciek, on my last post to you:  R.I.P.
Tore

Offline dougie47

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3744 on: 06 Aug , 2017, 15:00 »
Hello everyone,

Thank you, Don, for informing us of this dreadful news. Maciek was always very helpful and kind and I have been particularly appreciative of his help in my U 47 book. Without doubt he was a highly respected expert in his field. As a talented researcher, he was kind enough to share his comprehensive knowledge with us. He will be very sadly missed by us all.

If anyone is not aware, Maciek is the author of the Torpedo Vorhaltrechner Project, which can be viewed here -

http://www.tvre.org/en/home-page

He also wrote the following page -

http://www.ubootwaffe.pl/en/u-boats/equipment/torpedo-tubes-of-german-u-boats

Best regards to all,

Dougie


Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3745 on: 06 Aug , 2017, 17:02 »
Hello Mr. Tore and All,


I have uploaded my latest version of Skizzenbuch into my Dropbox folder... I only changed page II and made a few spelling corrections.


Regards,
Don_
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Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3746 on: 07 Aug , 2017, 01:51 »
Hi Don,
excuse me for my insistence, but I don't understand if you uploaded the file Skizzenbuck on your Dropbox folder just for the insiders, or if it's vailable for all interested on U-Boats....
Consider that I have not any experience of Dropbox....
Thanks in advance for answer.
Cheers.
Filippo

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3747 on: 07 Aug , 2017, 10:22 »
Hello Filippo,


I (The Managing Editor) had four (4) contributors to Skizzenbuch; Mr. Tore (The Main Expert), Maciek (Now Deceased Expert), Simon (Art Work), and Mark (Help with German Text Translation). Anytime I make a change to Skizzenbuch, I notify my contributors so they may review the content in my Dropbox folder and suggest any needed corrections or changes. This is the process that we have followed for over three (3) years while I have written/managed Skizzenbuch.


Skizzenbuch is not a released book as of yet... Currently, I sent a book proposal to the Naval Institute Press, but I am not naive about the prospects. So I have two (2) alternative plans as well; publish the book on my own or distribute the book as a encrypted PDF free over the internet. The most expensive option for me is the free PDF file over the internet because of the cost of the encryption software. I will not allow Skizzenbuch to be changed without my control of the content!


So, this is where I stand on the distribution of Skizzenbuch to date! I believe that "Skizzenbuck: U-Boat Type VII C Project" is about finished and very few changes will occur after today. I am in a situation where I am waiting on a Publisher's decision, or if that fails; I must come up with the cash needed for one of my other two (2) options.


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3748 on: 07 Aug , 2017, 21:28 »
Hello Mr. Tore,


I have a question for my own personal knowledge about resupplying fuel and lub oil to the U-Boat.
1. I assume they can use the resupplying port's pumping pressure, or use the U-Boats Aux lub oil pump to fill the lub oil tanks.
2. Do they press lub oil through the diesel engines, or do they fill the lub oil tanks by pressing clean lub oil through the diesel engine's normal supply lines?


Last question...  My U-570 Plate 9  (fuel oil) and Plate 14 (lub Oil) show the filling lines on the port side. However, the attached photos and Simon's drawings show the U-Boat accepting the resupply on the starboard side.  Are the plates wrong?


Regards,
Don_
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Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3749 on: 08 Aug , 2017, 01:21 »

Don.
I am right now up in the mountain for a couple of days under slight pressure of my wife to  attend som Plays, thus limited access to my papers.
However the lube oil of the VIIC GW engines without lubeoil centrifuges are based on a so called dry sump principle which means each mainengine has generally its own separate system with system tank. Normally you don`t fill up the systemtanks directly by shore supply, you top up or fill the lubeoil storage tanks I or II (port &stb) and take a possible luboil supply to the system tanks from the storagetanks.  In case of need you can indeed use the aux luboil/fueltransferpump to distribute the oil internally.
You never take fresh luboil from ashore directly through the engines, always to the storage tanks through the course filters.
As to the lubeoil filling pipe, I  guess the external hose filling cap is slightly to the starboard almost on the top of the presurehull. The downpipe inside the pressurehull follows the starboard side of the fore enginroom bulkhead door and the coursefilter ( nuts and bolts) underneath the floorplate starboard side having a crossover to the valvestchest on the port side. So use Simons drawings as far as I remember they are correct. I`ll revert as soon as I can find my images.
Tore

Offline SG

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3750 on: 08 Aug , 2017, 05:21 »
I just read about Maciek, and am shocked and deeply sad. The Forum has lost a precious source of information, a most fine researcher, one of its cornerstones in fact. He seemed to know every single part of a Uboat, and he was always available to provide information, even the apparently unanswerable information, for the ones in need. A major blow to the Uboat enthusiasts worldwide and to my morale. But, as Don said, we'll catch up with him sooner or later and will have the most pleasant technical conversations about uboats in those vast oceans up there somewhere, i have still a lot of unanswered questions to ask.
Farewell Maciek, you will be greatly missed!




« Last Edit: 10 Aug , 2017, 09:47 by SG »

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3751 on: 08 Aug , 2017, 08:29 »

Don.
I guess it would probably be easier to have a look at plate 14 and 9 simultaneously as plate 14 only indicate inlet and outlet of the fuelling and lubeoil supply. I have tried to combine the two on my image below. You`ll see that both  hose connections for fuelling inlet and lube oil supply are situated almost at the top of the pressurehull eg nearly at the center. Contrary to my memory the downpipe and strainer for the lubeoil supply is on the port side of the engine room front door whereas the fuelling pipe is on the starboard side going under the floorplates to the strainer before crossover to the distribution valvebox.
Hopefully the image is selfexplanatory.
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3752 on: 08 Aug , 2017, 20:41 »
Hello Mr. Tore and All,

Thank you for the quick response about re-supplying the lube oil and the fuel oil to a U-Boat Type VII C.

I have made changes to the following pages: 123, 151, 171, 178, and 243 (replaced a photo). I changed these pages with new 3D images from Simon who has done outstanding work! The latest version of Skizzenbuch has been uploaded to Dropbox...

Mr. Tore - Your wife has been with you for over 50 years, and she deserves your full attention! Keep focused on the most important relationship in your life, and the rest will fall into place...

Kind regards,
Don_ 
A man's got to know his limitations...
Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3753 on: 09 Aug , 2017, 00:53 »
Don, we are just on the way to the high mountain theater raining and temperatures hoovering around 8 centigrade, open air theater for 6 hours and 3 hours driving. Indeed my wife deserves the effort, we actually married in 1953 when I still was the chief of U 995 KNM Kaura and got a week off for marrying. Reverting in a small week.
Tore

Offline karel

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3754 on: 15 Aug , 2017, 04:42 »
Hello all. Just came back from my vacation and learned this terrible news :(   

I sitting here shocked, i had a few conversation bits with him and he was clearly a fantastic person. I have spent countless of hours on his websites and reading his input on this forum.
A really valuable, friendly and open community member.

R.I.P Maciek.
« Last Edit: 15 Aug , 2017, 04:44 by karel »

Offline David83

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3755 on: 16 Aug , 2017, 13:13 »
Rip Maciek      :'( :'( :'( :'( :'(

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3756 on: 17 Aug , 2017, 23:07 »
Hello Mr. Tore,


I have been reviewing the bow hydroplane clutch and drive mechanism; How does this drawing look to you?


Regards,
Don_
« Last Edit: 17 Aug , 2017, 23:55 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3757 on: 18 Aug , 2017, 03:11 »
Don
Exellent images. I guess it shows the arrangement of the old VIICs The latest executions did not have the atwartship shaft going right to the hydroplanguard and the shaft ended in a nut fixing halfway on the plane having an accesshatch right on the top where the nut was situated. As far as I remember the void space of the plane was filled with some sort of epoxy or recine. There was no contact between the hydroplane and the guard.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3758 on: 18 Aug , 2017, 22:50 »
Hello Mr. Tore,


Here is my 2nd attempt at the drawing...  What do you think? Also I found a photo that shows a hydroplane removed...


Regards,
Don_
« Last Edit: 18 Aug , 2017, 22:52 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3759 on: 19 Aug , 2017, 00:56 »
Don.
Again excellent images, the hydroplanes are fixed by a nut, not bolt. I remember once being submerged the fwd. hydroplane operator had trouble operating his hydroplane which according to him did not respond and the hydroplane seemed to be locked in a down position. When I crawled in to the narrow space i discovered that the mechanical connection from the motordrive to the transmitter for the resistive network was broken and the electric indicator in the controlroom showed full up whereas the plane was full down. Otherwise your images shows one of the drawbacks of mechanical operations, the numerous greasing points required.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3760 on: 19 Aug , 2017, 16:41 »
Hello Mr. Tore and all,


I updated pages 194 - 198 and uploaded Skizzenbuch 11 x 17 - M + I.PDF into my Dropbox folder...


Regards,
Don_
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3761 on: 19 Aug , 2017, 19:53 »
Hello Mr. Tore,


After doing a little more research...  It looks like David Westdood's book "Anatomy Of The Ship - The Type VII U-Boat" the forward and aft hydroplane drive motors are a hydraulic type motor.  I could see this type of motor because the hydroplane arm comes up against a metal stopper. Therefore, I would assume that the dual rudder motor is also an hydraulic motor as well...


However, there is nothing in the German Plans 1 thru 34 to indicate electric or hydraulic motors driving/controlling the hydroplanes or the dual rudders.


I checked the electrical plans for the Type VII and Plan 10 shows electric motors.


Could David Westwood's book be wrong?


What do you think?


Regards,
Don_
« Last Edit: 19 Aug , 2017, 20:50 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3762 on: 19 Aug , 2017, 22:30 »
Hello Mr. Tore,


I think definitely electric motors...  I was wondering if they had stall motors when the planes reached their limit - I found out there were 'Limit Switches" for all three planes and rudders.  I have attached the translated drawing...


Regards,
Don_
« Last Edit: 19 Aug , 2017, 23:24 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3763 on: 20 Aug , 2017, 00:26 »
Don.
Hydraulic operation of the hydroplanes ,and rudders, were the most common systems for submarines in my time, and I remember coming back from my submarine education in UK and onboard a VIIc, the most stricking exstensive differerence was the use of electric driven hydroplanes and rudders. You are right in your assumption both hydroplanes and rudders were electrically operated on the VIICs.
« Last Edit: 20 Aug , 2017, 00:36 by tore »

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3764 on: 09 Sep , 2017, 12:30 »
Hello Mr. Tore,


When will you be leaving your country home and heading back to the city? From your description, it looks like the fall and winter months at the country home location will get very cold and tons of snow...


Here in sunny Georgia, my summer project in 90 degrees plus weather was to re-do my back yard hillside. The builder placed burlap covering on the hillside which rotted away within 2 years and allowed the weeds to grow around the plants. So, I stapled down a heavy fiber covering to prevent erosion and to stop the weeds from growing. I built a 150 foot stone retaining wall, and had a contractor to place Railroad Ties on the upper part of the hillside, and red mulch covering the hillside area.


This project took about 2 months and I told my wife Maureen that my "Honey Does" were all used up for this year...


Regards,
Don_
« Last Edit: 09 Sep , 2017, 16:39 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3765 on: 09 Sep , 2017, 12:32 »
MY last photo...
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3766 on: 09 Sep , 2017, 13:38 »
Don.
Amazing garden, way out the wilderness where we are living. We are just in the final stage of harvesting, primarily, mushrooms and berries before shutting up the farm for the winter. The last item is very complex as i have to drain about a mile waterpipe, washing machine and dishwasher, internal waterpipes etc etc. Plus filling up the waterlocks with antifreeze and blow all the pipes by compressed air before eveything goes into winter freezer. Hope to be able to return to the civilization and proper broadband by end this month. In the meantime the moose hunting has started in our forest and it is safer to stay at the farm enjoying the autumn colours.
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3767 on: 18 Sep , 2017, 16:39 »
Hello Mr. Tore,


Can you tell me what these markings on the hull casing and on the saddle tanks are representing?


Regards,
Don_
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Offline VIC20

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3768 on: 18 Sep , 2017, 17:45 »
The roman numbers fit to the number of the MBTs at this position.
The marking V is where MBT 5 is and III is where MBT 3 is located at.


(but of course I have no idea what it really is  :) )


Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3769 on: 19 Sep , 2017, 01:08 »
Hello Mr. Tore,


Simon and I have been discussing the Kingston valves in the saddle tanks.  I have a very good photo of U-99 and the Kingstons look to be almost square. However, the Kingstons look quite different on U-995???


Did the Germans need to rebuild the saddle tanks during the restoration?  See the images below:


Regards,
Don_
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3770 on: 19 Sep , 2017, 01:11 »
Hi Mark,


You know, sometimes I believe my brain goes out on one of those senior tours.  It looks like you are correct.. Those would have been added when they restored U-995 for the museum.


Thanks,
Don_
« Last Edit: 19 Sep , 2017, 01:15 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3771 on: 19 Sep , 2017, 01:44 »
Hi Don and Mark.
As mention many times before, the museum U 995 do not show the real U 995 and I can not remember the markings in question. I checked with the limited documentation I currently have access to and I guess the markings are related to the alteration to the hull, making the museums version. The markings were not on the hull at the arrival Kiel from Norway, the first time I noticed the markings was when the hull was placed on its concrete bed at Laboe and having access doors for the visitors. As to the Kingstons for MBT3 they are indeed rectangular, but welded shut for security reasons, as the fore free flood gates in the casing. It is possible to crawl into MBT 3 through the Kingstons, I have done it myself, and to climb on the casing side using the free flood gates as step holes ( which I have not done). My image below shows the story.
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3772 on: 19 Sep , 2017, 03:38 »
Hello Mr. Tore and All,


I found the location of a plate for access to the MBT 3 air shaft.  This was pointed out (fold-out schematic in the back of the book) in the U-Boat Archive Series Volume 7 – REPORT ON U-570 – H.M.S. GRAPH…

Regards,
Don_
« Last Edit: 19 Sep , 2017, 03:48 by Don Prince »
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3773 on: 21 Sep , 2017, 00:04 »
Hello Mr. Tore,


I have been reviewing Skizzenbuch and I made what I believe is a correction to the lower right drawing on page 350.  I had the "Emergency Shut-Off Valves" swinging outward. I believe the valve truss structure was designed for the valves to swing inward. Do you agree?


Regards,
Don_
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3774 on: 21 Sep , 2017, 01:40 »
Hi Don.
I am in my car for a two days trip. My first impression is that your correction is OK. Reverting tomorrow. Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3775 on: 21 Sep , 2017, 23:43 »
Hello Mr. Tore,


Do you know if the MBT 3 Emergency Shut-Off valve heads are round or rectangular like the Kingstons valves for the Saddle Tanks? The uhistoria.com drawing sort of looks like they may be rectangular, but I'm not sure after talking with Simon...


Regards,
Don_
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3776 on: 22 Sep , 2017, 05:32 »
Don. I guess the emergency shut off vents for the MBT3 ventingducts are swinging inwards for open position. Further I would guess the venting valvediscs  are circular.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3777 on: 22 Sep , 2017, 23:13 »
Hello Mr. Tore,


I have been updating the uhistoria.com drawing by labeling all the frames.  I noticed that FBT 2 and FBT 4 do not extend to the full end of the taper.


FBT 2 starts at a taper and extends to frame A24 and then the tank extends to D34
FBT 4 starts at D46 and then the tank extends to D62 and then the tapered area continues for a few frames
See my attached drawing...


It looks like the tapered ends are not part of the Fuel/Water Ballast system. I have a photo of what looks to be a late Type VII C, or Type VII C/41 where there seems to be 3 vent holes in the tapered area of FBT 2 at the bottom side of the tank. I have not see this on other Type VII U-Boats; was this modification documented anywhere?


See my attached photo...


Regards,
Don_
« Last Edit: 22 Sep , 2017, 23:17 by Don Prince »
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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3778 on: 23 Sep , 2017, 12:14 »
Don. You are rigth the fairings of the MBT2 and 4are not a part of the sadletanks volume. They are only plates for streamlining the ends of the tanks. I cannot explain the floodgates on your image but having checked my files of VIICs and VIIC/41s there are no such floodgates. On the museum VIIC they have made a few slots at the bottom of the tanks with a dripnose, this was never on the original U 995 or KNM Kaura.
Tore

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3779 on: 23 Sep , 2017, 16:01 »
Hello Mr. Tore and All,


I corrected all the FBT 2 and FBT 4 drawings in Skizzenbuch to reflect the forward and aft fairings which are not part of the fuel/ballast tanks. The latest version of Skizzenbuch is in my Dropbox folder...


Regards,
Don_
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Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3780 on: 27 Sep , 2017, 16:37 »
Hello Mr. Tore,


I uploaded the latest version of "Skizzenbuch 11 x 17 - M + I.pdf" to my Dropbox account and I uploaded a new "Image File" folder with all the images 001 - 768, each image has the page number referenced.


Regards,
Don_
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Offline VIC20

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3781 on: 27 Sep , 2017, 20:27 »
Is page 46 new? I can’t remember seeing it before.

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3782 on: 28 Sep , 2017, 02:04 »
Hi Mark,


No page 46 is not new... Strange that you should ask?


I just made a correction to page 46 while doing a review...


The RED needle is pointing to the second gradicule on the RED scale on the differential manometer pressure gauge. This means the Q Tank has a positive differential pressure of 2 atü above the outboard pressure. The U-Boat Diving Regulations Manual No. 381 requires action to be taken because there is a possibility of a ruptured Q Tank if not vented immediately. Q Tank was designed with knee structures to resist external compression forces, but not internal expansion forces.


I changed the word from blowing to vented...


Regards,
Don_
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Offline VIC20

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3783 on: 28 Sep , 2017, 05:32 »
Just imagine if they had this wrong in the original manual  ;D

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3784 on: 28 Sep , 2017, 14:35 »
Hi Mark,


No, that was just my dumb error...  There was no manual showing the Differential Manometer, so I improvised. A few years ago, I confused the words blowing and venting! that's why I'm going back and reviewing Skizzenbuch again. I made lots of errors in the beginning...


Don_
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3785 on: 01 Oct , 2017, 13:04 »
Hello Mr. Tore,


Page 109 had the following sentence...


"Hence, the Junkers internal and external exhaust casing in the aft torpedo room has a shut and well seated grinding valve plate and a shut external flap valve located in the external Junkers exhaust casing which provides a double water barrier and preventing a water intrusion into the Junkers exhaust and cylinder chamber."


There is no grinding valve plate, so I changed it to...


"Hence, the Junkers internal and external exhaust casing in the aft torpedo room has a water trap located between the external/internal exhaust valves and the compressor’s air intake to impede sea water intrusion into the Junkers exhaust and cylinder chamber.


Does this change meet with your approval?


Regards,
Don_
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Harry Callahan, SFPD

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3786 on: 04 Oct , 2017, 00:17 »
Hello Mr. Tore and All,


I have uploaded the latest version of Skizzenbuch to my Dropbox folder.  I have corrected the Prologue (20 pages) and the first 175 pages thus far. It may take me a few weeks or so to complete my review.  If anyone sees a problem anywhere in Skizzenbuch, then please let me know and I will make the necessary corrections.


Regards,
Don_
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3787 on: 14 Oct , 2017, 21:43 »
Hello Mr. Tore,


I was wondering if you had any photos or drawings showing the gate valves on the common air venting trunk for FBT 2 and FBT 4? Was there enough room below the wooden deck and the fairly small metal deck door to have an attached hand wheel to open/shut the gate valves. or was the hand wheel just removed?


See attached photo...


I can see where there would be space for  the FBT 2 residual gate valve hand wheels could be present...


Regards,
Don_
« Last Edit: 14 Oct , 2017, 21:47 by Don Prince »
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Offline NZSnowman

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3788 on: 14 Oct , 2017, 23:34 »
Hello Mr. Tore,


I was wondering if you had any photos or drawings showing the gate valves on the common air venting trunk for FBT 2 and FBT 4? Was there enough room below the wooden deck and the fairly small metal deck door to have an attached hand wheel to open/shut the gate valves. or was the hand wheel just removed?


See attached photo...


I can see where there would be space for  the FBT 2 residual gate valve hand wheels could be present...


Regards,
Don_

Hi Don

The gate valves for FBT 2 and FBT 4, never had a hand wheel, this was an old mistake on my 2D drawing that Tore and I noted.

Also the hatches you have arrow are not the hatch cover for gate valves. The hatches you are talking about are the next ones forwards.

Offline NZSnowman

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3789 on: 14 Oct , 2017, 23:41 »
Hello Mr. Tore,


I was wondering if you had any photos or drawings showing the gate valves on the common air venting trunk for FBT 2 and FBT 4? Was there enough room below the wooden deck and the fairly small metal deck door to have an attached hand wheel to open/shut the gate valves. or was the hand wheel just removed?


See attached photo...


I can see where there would be space for  the FBT 2 residual gate valve hand wheels could be present...


Regards,
Don_

Below you are see the two hatches for the gate valves.

This images has been resized. Click to view original image.


Offline NZSnowman

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3790 on: 14 Oct , 2017, 23:48 »




You can see above that a handle slotted into the hex reset on top of the cover. The hatch cover is angled because there is not room under the decking for the gate valve.

Do sure what the handle look like, sorry  :'(
« Last Edit: 14 Oct , 2017, 23:55 by NZSnowman »

Offline NZSnowman

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3791 on: 14 Oct , 2017, 23:51 »

Here are the real hatches on U-826  :)

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3792 on: 15 Oct , 2017, 01:42 »
Hi Simon and Mr. Tore,


U-826 was commissioned on 11 May 1944 and probably one of the last Type VII C's  built.  It looks like the RFO /Water Ballast gate valves can be open/shut without opening any metal doors on the deck.


How about the earlier Type VII C's...  I have attached a plan for U-552 which was commissioned on 4 December 1940.  I have marked where I believe the gate valves are accessed for FBT 2, and I have also marked what I believe to be the access doors for the FBT 4 gate valves.


See attached drawing,
Regards,
Don_
« Last Edit: 15 Oct , 2017, 02:25 by Don Prince »
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Offline NZSnowman

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3793 on: 15 Oct , 2017, 02:31 »
Don, as seen in http://models.rokket.biz/index.php?topic=921.msg20817#msg20817 if they are the hatches for FBT 2 gate valves they would have the worng frame number.

I will try to post pictures of FBT 4 hatches tomorrow.

As for the earlier Type VIIC's, if you look hard enough you will see them on most boats. The only thing I have noted is that on the some late war Type VIIC/41 they sometime used a wooden hatch.

Early Type VII's with hatch.

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3794 on: 16 Oct , 2017, 02:09 »
Hello Mr. Tore and Simon,


I now know the FBT 2 and FBT 4 gate valves never had hand-wheels because there is no space below the wooden deck.  I think it was possible for the FBT 2 residual gate valves to have hand-wheels, but most likely they were removed to keep the change-over process as uncomplicated as possible.


I have attached one of Simon's drawings and a photo where it looks like there is a hole in the wooden deck to provide access to the gate valve towards the center of the deck.  What do you all think?


Regards,
Don_
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Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3795 on: 16 Oct , 2017, 02:41 »

Hello Mr. Tore,




Are you and the wife back from your farm and in the big city yet?  Here in hot southern Atlanta Georgia; If the weather forecast even suggest that there will be a snow dusting, then all the schools are closed. People make a mad rush to all the grocery stores and buy all the milk and bread they can find. I guess the fear of starvation makes people do crazy things.  I'm originally from northern West Virginia where I had to walk to school in 2 - 3 feet of snow, they never closed the schools because of the winter weather.  I assume it's the same way in Norway; you just tough it out!...


Regards,
Don_
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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3796 on: 16 Oct , 2017, 08:49 »
Hi Don. Yes we are back in the civilisation, only to discover we forgot a couple of important items which shall be picked up by our grandson this week. Although we have had our first frosty nights, no snow as yet don`t miss it in my age. It take a few days to get back to the daily life in the city, but we are almost there.
Tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3797 on: 16 Oct , 2017, 15:50 »
Don, the small hole in the deck is a access hole for a locking handle for this hatch (see below). I not sure how the locking system works, you either lift or push down on the handle.


This images has been resized. Click to view original image.

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3798 on: 16 Oct , 2017, 19:17 »
Hi Simon,


Great info...  I have attached a photo that shows the FBT 4 and FBT 2 vent holes in the saddle tanks.


I have marked with red dots on your drawing where I believe the FBT 2 residual gate valves are located under the wooden deck hatches. Do you think this is correct? Also, is there room to have hand-wheels attached to these gate valves under the deck, or were the hand-wheels always removed for this set as well? That photo I had of a crewman getting out in bad weather with a hand wrench (Claw) tool makes me believe the hand-wheel was once a possibility...


Regards,
Don_
A man's got to know his limitations...
Harry Callahan, SFPD

Offline NZSnowman

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3799 on: 16 Oct , 2017, 19:44 »
Hi Simon,


Great info...  I have attached a photo that shows the FBT 4 and FBT 2 vent holes in the saddle tanks.


I have marked with red dots on your drawing where I believe the FBT 2 residual gate valves are located under the wooden deck hatches. Do you think this is correct? Also, is there room to have hand-wheels attached to these gate valves under the deck, or were the hand-wheels always removed for this set as well? That photo I had of a crewman getting out in bad weather with a hand wrench (Claw) tool makes me believe the hand-wheel was once a possibility...


Regards,
Don_

Hi Don,

I have not research the FBT 2 residual gate valves http://www.uboatarchive.net/U-570/U-570Plate16.htm valves b1 or d1 so I not sure. Since I am working on the saddle tanks I was soon start working on the piping that are found around them.

Simon