Tores mailbox VIIC and VIIC/41 operation and technical details

[Don Prince]

Hi Maciek,


I only see one shaft in the control room...


Regards,
Don_

[SnakeDoc]

Now I have a real problem...  In my Skizzernbuch page 335 I have images of the drive shafts for the Saddle tank Kingstons and there is only one drive shaft for each tank (photos) of U-995... Am I wrong?

See attached photos.


In the U-boat Information for U-boat Type VIIC you can read:

For Flood valves for main ballast and reserve fuel oil tank 4 stb. and port   4

--
Regards
Maciek

[SnakeDoc]

The second pair (first pair you have located correctly in petty officers room) of the shafts for FBT 2 flooding valves is located in galley. See attachments.
The third photo presents red linking shaft (at the right edge of photo) going through the WC cabin.


--
Regards
Maciek

[NZSnowman]

Maciek is 100% correct about the different thickness of sheet metal on the saddle tanks:
1. R1, R2, and Q Tank outter sheet metal is 11.5 mm thick
2. FBT 2 and FBT 4 outter sheet metal is 6 mm thick
3. The internal walls of Q Tank are 13 mm thick

PS - after looking at mt trusty steel ruler with inches on one side and mm on the other side; we're not talking about sheet metal. The 6 mm plate steel for FBT 2 and FBT 4 is a little under a 1/4 inch, and the 11.5 mm plate steel for R1, R2, and Q Tank is a little over 7/8 inch steel.  This plating would have to be rolled to fit the framing.  You are not going to bend that into place...
 

I not see this drawing before, but you know if you look at this drawing, you can see all four expansion tanks for the Fuel oil compensating system marked on it.

[NZSnowman]

If you download this picture of U-352, you can coun the framing very easy.

The damage look to me to start at No. 57

http://www.olympusdiving.com/wp-content/gallery/U352-Breakout-Gallery/U352_19border_copy.JPG

[NZSnowman]

Hi Don & Maciek

I am trying to model the top of the CT, do you guys have any good photo's?


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


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


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

[Don Prince]

Hello Mr. Tore and Maciek,


Wow! I had it completely wrong in Skizzenbuch about the design of the drive shaft mechanism for FBT 2 and FBT 4.  I just ran into this misunderstanding on my part yesterday when discussing the sunken U-Boat with Maciek.  That 2nd screw jack mechanism led me to believe that Q Tank was blown apart. I didn't know that there was two (2) screw jack mechanisms in each saddle tank blister (FBT 2 and FBT 4, Port and Starboard).  I sure hope I don't have anymore of these lightning strikes...


Simon,


I have photos in books showing the tower in detail at the factory when being built.  After I get Skizzenbuck straightened out, I will copy the photos and email them to you...


Regards,
Don_

[Don Prince]

Hello Mr. Tore and Maciek,


I have corrected Skizzenbuch to reflect the correct information about the number of drive mechanisms for FBT 2 and FBT 4.  Would you all please review pages 334 and 335 and let me know if anything needs corrected or changed in any way?


The new file Skizzenbuch 11 x 17 - M + Index.pdf in in my dropbox folder...


Regards,
Don_

[SnakeDoc]

Hi Don,

I have corrected Skizzenbuch to reflect the correct information about the number of drive mechanisms for FBT 2 and FBT 4.  Would you all please review pages 334 and 335 and let me know if anything needs corrected or changed in any way?

I would change the sentence in bold.

The Type VII C U-Boat schematic below has the port Kingston Flap valves highlighted to show their location within the lower section of the saddle tanks for FBT 2 and FBT 4. Of course, there will be similar Kingston flap valves on the starboard saddle tanks. The four (4) individual Kingston flap valves are controlled (open or shut) by two (2) removable hand crank that attach to the drive shaft which passes through the pressure hull and engages the screw jack mechanism for each of the four (4) tank (FBT 2 and FBT 4, port and starboard). The locations of the drive shafts are designated by numbers 1 through 8 in the schematic. The mechanical diagram to the left shows the hand crank attached to the Kingston drive shaft which turns the screw jack external to the pressure hull, but within the saddle tank structure. The saddle tank Kingston flap valves open inward and swing from the bottom of the flap. The image of U-995 shows two (2) of the Kingston flap valves highlighted in YELLOW, and the protective grill for the Q Tank mushroom valve to the right. It may be difficult to read the numbers, but the saddle tanks have two different metal cover plating thicknesses; FBT 2 and FBT 4 have 6 mm thick outer plating, while R1, R2, and Q Tank have 11.5 mm thick plating because they are pressurized.

Maybe something like this:

The four (4) individual Kingston flap valves are controlled (open or shut) by two (2) removable hand crank that are attached to two (2) drive shafts which passes through the pressure hull and engage two (2) screw jack mechanisms (one for mechanism for two (2) flaps, two mechanisms for four (4) flaps).


The label at the bottom of the drawing:

Drive Shafts for the Kingston Flood Valves (2 per shaft)

Drive Shafts for the Kingston Flood Valves (2 flood valves per shaft)

--
Regards
Maciek

[Don Prince]

Hi Maciek,


I will make the changes as suggested...


U-352 Q Tank grill is correct; only half was blown away...


Regards,
Don_

[Don Prince]

Hello Mr. Tore, Maciek and All,


I updated the the image of the saddle tank/expansion tank on page 83 after viewing the photos that Simon posted.  I believe the current version better reflects the actual design (drawing attached).


Thank you Simon...


Maciek, I made the text changes to page 334 and the image change.  I did a little re-wording and made the long sentence into two shorter ones and eliminated all the brackets.


Let me know if it's OK...

[SnakeDoc]

Hi Don,


now it looks good to me.


--
Regards
Maciek

[NZSnowman]

Simon,


I have photos in books showing the tower in detail at the factory when being built.  After I get Skizzenbuck straightened out, I will copy the photos and email them to you...


Regards,
Don_

Don, here the update top of the CT.

[NZSnowman]

Port Side Main Exhaust Valve

For the last several weeks I’ve been working on the exhaust valve, and for the first time I feel like I’ve made some significant improvements on the section of the U-boat. The drawings below are based on U-352 and are as accurate as I can make them base on the imaging of this boat. There are still details that are missing that I will have to guess.

I have also modelled all the internal structure, or was much as I can

Detail that I’m missing or cannot find are:

• The inbound cooling water flange (I believe it must be near the top of the main valve).
• The pressure release valve.
• How the box (which houses gearing that opening and closing of the valve inside) is attached to the side of the main exhaust valve.
• How the grinding teeth seats when the main exhaust valve is closed (I imagine there must be a small internal flange?).
• The hinge mechanism for them main exhaust valve.

Fig. 1. Looking Inboard, to the stern.


Fig. 2. Looking Inboard, to the bow.


Fig. 3. Looking outboard, to the stern.


Fig. 4. Top.


Fig. 5. Looking to the stern.


Fig. 6. Looking outborad.


Fig. 7. Looking inborad.

[NZSnowman]

Cross-section Views







As always all can be resized, by clicking on the original image.

[NZSnowman]

Don, Tore & Maciek.

• Any idea how the grinding teeth are seated when the main exhaust valve is closed?
• Are there any example of this type grinding hinge mechanism? I search the internet but can't found anything

[Don Prince]

Hi Simon,


This is what I have in Skizzenbuch from Mr. Tore...


Regards,
Don_

[maillemaker]

Hi Tores,

Do you have any knowledge about how to obtain/compute firing solution information?  I am trying to use the RAOBF (range and angle on bow finder) and other tools playing the Silent Hunter 5 simulator on 100% realism.  I'm am finding the finding of target speed, range, and AoB tricky.

Generally I opt for 90-degree approaches so that range is irrelevant.  I use a "fixed wire" method to compute speed by adjusting my heading to match target bearing (0 degree bearing) and then use the stopwatch to measure how long it takes the target to traverse the vertical reticle in seconds.  If I know the ship length from the recognition manual I can then calculate target speed.

How did you guys come up with the target information?

Steve

[SnakeDoc]

Hi Steve,


for historical methods of determining target data check this site:
http://tvre.org/en/acquiring-torpedo-firing-data


--
Regards
Maciek

[Don Prince]

Hello Mr. Tore and All,


Tuesday morning my Post Leather Bound First issue of Skizzenbuch was delivered to my doorstep via UPS. There was a litter inside the box taped to the binder stating that Schiffer Publishing LLC has decided not to publish the book. After a year and a half, now 2 months before the release date they canceled the book! They say the niche market is too small at this time.


To say the least; I'm a little %$*&T#, and I'll have to think about the situation...


Don_   

[dougie47]

Hello Don,

Really sorry to hear this news, Don, this must be intensely frustrating for you. I'm hoping another publisher picks it up at some point. Keep your chin up if you can.

Best regards,

Dougie

[Don Prince]

Hi Dougie,


Thanks for the encouragement...  I tried several other publishers and I get the same old line; too much cost to publish the book with the current readership base.  It looks like the book publishing market is shrinking each year because of printing costs and the availability of e-books.


However, the e-book readers have limitations to the document's format. I looked into Skizzenbuch in a e-book format, but none have that capability. Besides, every e-book device is dependent upon the sponsor and have a different format. I am thinking seriously about applying for a publishing company LLC here in the state of Georgia. I could then create a named publishing company and distribute a CD/DVD with a PDF book format and sell them on Amazon.


I am looking into PDF protection software where the file can not be copied from the CD/DVD, but I am considering the option of allowing the customer to print the file. I have a second Skizzenbuch book on the Type IX C & C/40 in the pipeline with over 100 pages completed. 


AS you can see, I have a lot of options to consider.  I could chuck it all and have my Skizzenbuch: U-Boat Type VII C Project with its leather post binder in my personal library, and create the 2nd book for my library as well...  Either way; I am very content!


Kind regards,
Don_

[karel]

 


Oh no. So sorry to hear about that. I was really looking forward for the release of Skizzenbuch since it contains valuable information for my game development efforts.
Hang tight Don Prince. I am sure that you will find an acceptable solution for your publishing problems. This unique historical knowledge needs to exists. I have wasted hundreds of dollars on various u-boat books that all contain the same generic information.

[tore]

My PC crashed three weeks ago leaving me out of touch with my mailbox which has been very frustrating and I am truly sorry not having been able to participate in the discussions and able to answer the questions put forward. However I got my PC back this week and used a few hours to  get updated. Don, I regret very much that your Skizzenbuch has been rejected, so many hours of your enthusiastic work not to be published. However a substantial part of the work is available on this thread, hopefully for some use of the many interested enthusisasts.
Again sorry for my absence.
Tore
 

[dougie47]

Hi Don,

There are some really average U-boat books out there, with some authors unable to tell the difference between a VIIC and an IX. So it gets really frustrating when properly researched material such as yours is prevented from book format simply due to financial reasons. I think I am going to have the same problem when I finish my U 47 book - the 200k+ word count and over a hundred images and drawings will not find favour with many publishers. So I guess I will be in the same boat as you.

The medium - whether printed book, E-book download or CD - is not as important as getting your research to be appreciated by enthusiasts. The CD via Amazon should accomplish this. It would also allow you to make updates as required and keep full control.  The only issue with the CD is that someone might try to rip it off and pass the files off as their own so the protection software for the pdfs sounds essential. 

Cheers,

Dougie

 

[Don Prince]

Hi Dougie,


If I decide to go ahead and publish Skizzenbuch, then I will do the following:



1. I plan to purchase the "CopySafe PDF Converter" application which is to prevent copying anything from the original PDF file and changing its contents. I plan on embedding the CopySafe Reader into the encrypted Skizzenbuch distributed document. You can copy the encrypted file, but that's it...


2. I will create "Kristall-Klare Publishing, LLC.  This will be done in the State of Georgia.  The LLC protects the single owner in legal matters. The only assets at stake are the publishing company assets.


3. Each PDF book published will have a US eBook Copyright.


I am seriously thinking about making this happen...


Dougie - some advice on publishing your book about your U-47. 


1. Keep the book in a standard format - publishers don't like to work too hard!
2. Keep a limit on the number of font sizes (preferably 2).
3. The legal stuff will drive a sane person crazy! - publishers want the profits, but won't legally have your back!
4. Your royalties (a low percentage) will be on the wholesale set price, not the retail price.
5. A PDF file may not be accepted by your publisher depending on their staff size. I had to create a TEXT File that had embedded print commands; <Insert image ###, Size, Location> / <TEXT: size, bold> / etc. All your drawings and photos must be in a separate folder and numbered to match the text file, or it could be something completely different.


I guess I may come off as a bit jaded (I hope not).  Best of luck my friend...


Regards,
Don_

[SnakeDoc]

Hi Don,

I'm also really sorry to hear that your publisher cancelled publishing your book.
This book is one of the few that really introduces something new into the topic
of U-Boat technology. I hope that you find another way of publishing your work.

Tore, I'm happy to hear from you again.

--
Regards
Maciek

[dougie47]

Hi Don,

Thanks for your advice, I will have to make some adjustments as per your point 5.

When you are really to sell please let us know and we can put a link on the AMP website towards the CD.

Cheers,

Dougie

[NZSnowman]

Hi All,
 
I am looking that the internal framing of the saddle tanks, and it looks like that the Germans changed the design of the internal spars sometime during the war. The ‘late war’ design looks more simpler and stronger than that early drawings from 1940.

Has anybody come across this before or can confirm the change in the design for me?

Thanks, Simon.

[NZSnowman]

Hello Mr. Tore and All,


Tuesday morning my Post Leather Bound First issue of Skizzenbuch was delivered to my doorstep via UPS. There was a litter inside the box taped to the binder stating that Schiffer Publishing LLC has decided not to publish the book. After a year and a half, now 2 months before the release date they canceled the book! They say the niche market is too small at this time.


To say the least; I'm a little %$*&T#, and I'll have to think about the situation...


Don_

Don, sorry about the late reply, I have had my head down working on the saddle tanks (have already spent over 60 hours working on them already). Sorry to hear about your Skizzenbuch. I think it’s the way of the modern world that books etc. are becoming more digital.

Perhaps using a PDF could have some benefit as you could embed multimedia into the file, to better illustrate your point of view or what you are explaining (e.g. 3-D imaging, sounds, animations, overlays/ multi layered pictures, Spreadsheets).

I think I am going to have the same problem when I finish my U 47 book - the 200k+ word count and over a hundred images and drawings will not find favour with many publishers. So I guess I will be in the same boat as you. 

Dougie, a pdf could be great option for your book, as you could link pictures directly to the text and add animation (e.g. the path Prien took etc.).

[NZSnowman]

Tore, Don & Maciek.

What is the smaller tank within the Regulating Tank 2, is it part of the Fuel oil compensating system?

[tore]

Simon.
The rectangular drawn inside the regulating tank2 port and stb is a crossection of the venting duct from MBT 3 port and stb. passing through the regulatingtank 2 to the main vent boxes on top of the pressurehull as tried to show on my image below. The regulating tanks 2 port and stb have no connections to the fuel compensating system as they are only used as regulating tanks.
Tore

[NZSnowman]

Simon.
The rectangular drawn inside the regulating tank2 port and stb is a crossection of the venting duct from MBT 3 port and stb. passing through the regulatingtank 2 to the main vent boxes on top of the pressurehull as tried to show on my image below. The regulating tanks 2 port and stb have no connections to the fuel compensating system as they are only used as regulating tanks.
Tore

Thanks Tore.

I just got a email from a friend that translated for me 'Luftschacht'  = 'Ventilation shaft'   

Two questions:

• Why do they need a Ventilation shaft, why couldn't they vent straight from the top of the tank?
• I imagine the opening for the vent shaft would be at the bottom?

[NZSnowman]

I might be a little confused, so it vents from MBT 3 tank?

Tore, Don't worry about me just got a little confused, for some reason I was thinking it was venting the saddle tank not from MBT 3 

[NZSnowman]

Tore, Don & Maciek,

Anybody has any idea about the size of the emergency shut-off valves for MBT 3?

Thanks.

[tore]

Simon.
My guestimate would be 600mm x 450mm.
Tore

[NZSnowman]

Simon.
My guestimate would be 600mm x 450mm.
Tore

Thanks, Tore.

This could be very close was there only about 555 mm between the frames.

Is could be the opening (forward Pressure Hull section)

[NZSnowman]

Interior framing for the MBT 3


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


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

[karel]

@Simon.Your work is amazing, i understand that this takes years to be finished but storing this historically accurate information in this way is super amazing. The educational value of this will be tremendous. Also noted your feedback about my game periscope. Luckily in our case we are not building an exact historical replica since people will be playing this while wearing VR goggles. We have to make many modifications to accommodate their comfort levels and interactions.

Also i hope that it is ok to post it here. Our submarine game got featured in UploadVR. There is also a little video there. What makes me especially happy that it has even gained attention from people who were not previously interested in submarines. http://uploadvr.com/atlantic-ghost-submarine/

@Don Prince
I was thinking about your Skizzenbuch situation. It is not much but i can offer to recreate a virtual prop version of your book and place it inside the sub. It would fit into game narrative since our main protagonist is not part of uboat crew and has a valid reason for owning that book. I know that it is far from having it out in real life but who knows, maybe in future it will prove as an useful item for "marketing purposes" if you do find a solution to your publishing problem.

Karel

[tore]

Simon.
I guess you got the idea
Tore

[NZSnowman]

@Simon.Your work is amazing, i understand that this takes years to be finished but storing this historically accurate information in this way is super amazing. The educational value of this will be tremendous. Also noted your feedback about my game periscope. Luckily in our case we are not building an exact historical replica since people will be playing this while wearing VR goggles. We have to make many modifications to accommodate their comfort levels and interactions.

Karel, how many poly can you push through the VR gear?

My model is now around 8 million poly

[NZSnowman]

The bulkhead between Reg tank 2 and Neg Buoy tank. How did they curve the bulkhead?

[tore]

Simon.
I don`t think it is only the bulkhead between regulating tanks 2 and the neg. buoyancy (Q)tank which is curved. In fact regulating/ fuel tank 1, regulating tanks 2 and the Q tank have all curved bulkheads as they are pressureproof. As the differential pressures between these tanks might vary considerably depending on their independent operation, the separation bulkheads have to be curved to resist the pressuredifferential. In spite of that, the regulating tanks have differential manometers indicating the differential pressure enabling a monitoring that the max differential pressures are not exceeding the max. allowable values.
Tore

[NZSnowman]

Simon.
I don`t think it is only the bulkhead between regulating tanks 2 and the neg. buoyancy (Q)tank which is curved. In fact regulating/ fuel tank 1, regulating tanks 2 and the Q tank have all curved bulkheads as they are pressureproof. As the differential pressures between these tanks might vary considerably depending on their independent operation, the separation bulkheads have to be curved to resist the pressuredifferential. In spite of that, the tanks have differential manometers indicating the differential pressure enabling a monitoring that the max differential pressures are not exceeding the max. allowable values.
Tore

Thanks, Tore.

Just finish the other side of the Q tank, next the regulating/ fuel tank bulkhead 1    It take me a while to model each frame within the saddle tank as each one is totaly different

One thing that is worrying, on the plan you used there are three (4 four in total) additional supports that run horizontally that look ‘C’ shape from above. However on the more detailed plans there is only one of these horizontal spar

You might find it interesting, the thickness of the steel for each bulkhead is 13 mm.

[Don Prince]

Hi Simon,


Only one "C" shaped support seems to make sense... The steel plate thickness of the exterior metal plating is 11.5 mm for R1, R2, and Q Tank (.45 inch). If the internal longitudinal supports, and the internal bulkheads were the same thickness as the outer plating, then all would have to be formed at a steel pressing plant and be assembles/welded together on site.


The saddle tanks FTB2 and FTB4 were 6 mm thick (.23 inch) for the outer shell. 


Regards,
Don_

[tore]

Simon.
A possible better image of the extra strengthening of the regulating/fueltank 1 and regulating tank 2 bulkheads belows shows there are only one bulkhead strengthening on each of the reguator/ fuel tank 1 and regulatore tank 2, hence in total of only three bulkheads. I guess these bulkheads were susceptible to damages hence extra strengthening. As far as I remember (vaguely) U 926 ( Our KNM Kya) had some signs of damage in this area.
Tore

[Don Prince]

Hi Simon,


One image shows the air shaft and the other image shows a different cutout of the ribs ((I guess for RFO 4).


Don_

[Don Prince]

Hello Mr. Tore,


I have a question about the Lubricating oil flow for either the GW or MANN engines?


On each side valve e1 selects the oil return tank port or Starboard, but the port diesel engine's oil pump only draws oil from the port side and it's the same for the starboard pump and diesel engine on the starboard side. I don't understand the reasoning behind this setup.  You could drain one tank and overflow the other tank with a non selective source and a selective return???

Also, I see no means to get the dirty oil into the dirty oil tank?

Regards,
Don_

[tore]

Don.
The return of the lubeoil can be selected to either of the luboil system tanks (port or starboard). In the case of contamination, mostly seawater, you are able to isolate and clean the contaminated oil. This system is based on a lubeoil sentrifuge cleaning system which was removed on the later VIICs. However you are  able to draw lubeoil from either of the system tanks by using the fueltransfer pump as a spare lubeoilpump as indicated on my image below.
The original sentrifuge system  had two pumps, one for dirty lubeoil from the  system tanks to the sentrifuge and one for supply of clean oil from the sentrifuge to the systemtanks. On the later arrangement the sentrifuge installation was removed and a larger filter installed in the system eleminating the sentrifuges and pumps, I don`t have a systemsketch of the latter system. On the aft engineroom bulkhead is  a handpump which enables emptying the contaminated oil from either of the systemtanks including dirty oiltank to overboard.
Tore

[NZSnowman]

Tore, Don, & Maciek.

Q. Would there be a wire mesh over the opening for the MB3 valve? (I just noted there a dotted line above the opening of the MB & RTO Tank, which has a wire mesh over the opening. There no dotted line above the opening MB3 valve ) http://www.uboatarchive.net/U-570/U-570Plate28.htm

Q. Was there a gasket on the venting valves, or just metal on metal?

[Don Prince]

Hi Simon,


I don't have anything to prove there is a wire mesh above the vent for the Type VII, but I believe there was.  Your, 2D drawings show the mesh.  I do have a quad-vent valve set for the Type IX that has the mesh.  I got that from Maciek...


Regards,
Don_

[Don Prince]

Hello Mr. Tore,


I change the Oil and filter on my car every 3,000 miles...  Do you remember how often they changed the 2 lube oil filters on the Type VII C diesel engines?


Regards,
Don_ 

[Don Prince]

Hello Mr. Tore,


Your opinion about the text and diagrams...


Regards,
Don_


"Lower Left - The return of the lube oil from the diesel engine can be switched to either of the lube oil system tanks (port or starboard). In the case of contamination (possibly seawater) you are able to isolate and clean the contaminated oil. This system is based on a lube oil centrifuge cleaning system which was removed on the later VIICs. However, you are  able to draw lube oil from either of the system tanks by using the fuel transfer pump as a spare lube oil pump as indicated on the image below.


Lower Right - The original centrifuge system had two pumps, one for dirty lube oil from the system tanks to the centrifuge and one for supply of clean oil from the centrifuge to the system tanks. On the later lubricating oil two (2) larger oil filters eliminated the need for the centrifuge purifier and the pumps. I don`t have a system sketch of the later system showing the exact location of the filters. However, the photo shows the two (2) filters in close proximity of the engine control panel. The hand pump mounted on the aft engine room bulkhead is used to dump contaminated oil overboard from either of the system tanks or the dirty oil tank.


Blown Head Gasket


Engine misfire with a gasket head-to-head leak causes lowered compression which results in a rough idling engine. Damage of this type may not cause overheating, coolant in the oil or any other outward sign. Overheating from a blown gasket when a head gasket fails between a combustion chamber and the cooling system, a loss of coolant and overheating are often the result. Oil in the coolant and coolant in the oil; head gaskets may also fail between the coolant passages and the lubrication system. This type failure may show up as oil in the coolant or coolant in the oil. Unfortunately, this failure will destroy the ability of the oil to lubricate and change the viscosity of the oil. The results could be a ceased up diesel engine."

[tore]

Tore, Don, & Maciek.

Q. Would there be a wire mesh over the opening for the MB3 valve? (I just noted there a dotted line above the opening of the MB & RTO Tank, which has a wire mesh over the opening. There no dotted line above the opening MB3 valve ) http://www.uboatarchive.net/U-570/U-570Plate28.htm

Q. Was there a gasket on the venting valves, or just metal on metal?

Simon.
I believe the MBT3 vents had a protecting wiremesh on top. I  think the vent seatings were metal to metal.
Tore

[tore]

Hello Mr. Tore,


I change the Oil and filter on my car every 3,000 miles...  Do you remember how often they changed the 2 lube oil filters on the Type VII C diesel engines?


Regards,
Don_ 

Don.
I don`t think you can compare a disposable car luboil filter with a complex large marine diesel luboil filter. Normally a marine luboil cleaninginstallation have sentrifuges. Such installation add weigth and require space which make it difficult to accommodate in a submarine. When the VIIC/41 was introduced weight become a problem as the increased diving depth required a heavier steel plating and every possible excessive weight had to be removed. The lubeoil sentrifuge and the reversing of the diesel engines were sacrificed and a large sofisticated lubeoilfilter was installed. Such a filter do not have a disposable insert as on the car engines, but are of a "selfcleaning" type, either by means of a reversible oilflow,back wash type, flushing the contaminations to the dirty oil tank or  a "knife filter" which has a long rotary steel knife ( brush) along steel steel filter insert which skims off the contamination dropping it to the bottom of the filter where it is drained to the dirty oil tank. I guess the VIIC had the first type for the lubeoil- and for the fuel the "knife" type filter after the fuelfilters. In your text showing the filters on the front of the engines it seems to me you are mixing up the double fuelfilters with the lubeoil filters. The VIIC lubeoil filters are single,  much larger, some 400 mm diameter and 600mm long,  and not generally visible, placed under the floorplating forward engineroom in the area where the  sentrifuges used to be.
As to the fuelfilters attached on the front , you have a port and starboard fuel knifefilter placed behind the hp fuelinjection pumps as shown on the image below. 
The drawback with lubeoilfilters is watercontamination, quite common on a submarine. You had to rely on a certain settling in the systemtank, however if the lubeoil emulsified you are lost, it happened once in three year with me.
Otherwise I believe the text is OK.
Tore

[tore]

Simon.
I am not sure of you text under blown head gasket and watercontamination. A leakage of water into the lubeoil system is not possible by a "blown gasket" between the cylinder liner and coolingwater system. As you`ll see from my image below, the upper part of the cylinderliner is raised uncooled in the way of the cyliderhead joint with the liner. Yet we had quite often the cylinders filled with seawater which in some rare cases caused emulsificaton of the lubeoil. The main reason for the waterintrusion was a leaking main hull exhaustvalve. These valves although equipped with a pneumatic grinding machine had a tendency to leak, some times filling the exhaust manifold and the cylinders with seawater submerged. As previously told, our starting routine was always to blow through the engine with the indicatorcocks open to blow out the water prior to starting, to prevent waterstroke. We even did that after diving to prevent water accumulating just after the dive, however as this increased the internal pressure in the boat we had to restrict such procedure. Yet seawater contaminations happened by leakages through the pistonrings down to the luboil systemtanks.
Tore

[Don Prince]

Hello Mr. Tore,


The 'Blown Head Gasket" was my post...


Regards,
Don_

[NZSnowman]

Vent valve for MB & RFO 2 Tank (Stb)


Fig. 1. Vent valve for MB & RFO 2 Tank.


Fig. 2. Vent valve for MB & RFO 2 Tank.


Fig. 3. Under deck view of the vent valve for MB & RFO 2 Tank.


Fig. 4. Deck view of the collection for the valve for MB & RFO 2 Tank.
This images has been resized. Click to view original image.

[tore]

Simon.
I guess the gatevalves are ok, but may be you should make som strengthening ribs on the valve casing and a bit heavier stuffing Box, see my image below.
Tore

[tore]

Simon.
As far as I remember the gatevalves did not have valve spindle extensions to the casingdeck. Wooden  deckhatches would be more appropriate. Particularerly for the isolating gatevalves, as at sea the casingdeck was awashed  all the time, operating the valves was difficult.  Hence a conversion to the fuel storage mode was usually done alongside in harbour.
Tore

[karel]

@Simon.


To answer your previous question. We currently have a command room in our build and it's triangle count is at 1.6 million. But it will quickly add up since in VR you need to render for both eyes. So 3.2 million for command room. Adding to some custom texture compression techniques that needs an extra geometry pass and the triangle count goes around 5 million. We are baking all our lighting but if we used realtime lights with realtime shadows then the triangle count for one room would easily reach over 10 million. But we are not going to use realtime lights. Also added minimal visual effects like bloom and slight color correction (https://www.dropbox.com/s/03y2dw06ry6hn8j/Screenshot%202016-12-30%2018.27.54.png?dl=0  <-- here is me trying to achieve Das Boot film LUT) and the pixel fill gets more expensive.


Then there are PBR materials, every material has a separate texture for albedo, specular, roughness, normal, ao, metallness and they all need to be as high as possible since you don't want visuals break down when inspecting object up close. Final touch is using 4xMSAA to get rid of all the pesky geometry alias and rendering this all becomes quite challenging. We need to keep it at 90 frames per second.  Luckily current generation GPU-s can chew trough triangle count pretty easily but trying to add this other stuff and the bottle neck will be quick to come.


That's the biggest challenge, how to balance this all that it would still look and run good.

[tore]

Karel.
I have of course no idea about creating a submarine game,but could`t resist to compare the Das boat scene, which I assume indicates das boot is under attack, with a journalists photo of me on KNM Kaura ex. U 995 demonstrating a submerged dummy attack. I guess the photo is pretty close to the area shown in the moviescene. Note the periscope on my photo is of the original type not the type fitted on present days U 995.
Tore

[NZSnowman]

Simon.
As far as I remember the gatevalves did not have valve spindle extensions to the casingdeck. Wooden  deckhatches would be more appropriate. Particularerly for the isolating gatevalves, as at sea the casingdeck was awashed  all the time, operating the valves was difficult.  Hence a conversion to the fuel storage mode was usually done alongside in harbour.
Tore

Tore, you are correct.
 
While researching the deck of the late war Type VIIC’s. I did noted that the German's had replaced these two small metal hatches, with wooden hatches on the late war Type VIIC’s.

[NZSnowman]

Simon.
As far as I remember the gatevalves did not have valve spindle extensions to the casingdeck. Wooden  deckhatches would be more appropriate. Particularerly for the isolating gatevalves, as at sea the casingdeck was awashed  all the time, operating the valves was difficult.  Hence a conversion to the fuel storage mode was usually done alongside in harbour.
Tore

Tore, you are correct.
 
While researching the deck of the late war Type VIIC’s. I did noted that the German's had replaced these two small metal hatches, with wooden hatches on the late war Type VIIC’s.

Tore, I was thinking about this hatch last night.
 
I am starting to think that they used this metal hatch throughout the whole war. We must remember that this section of the deck on KNM Kaur was rebuild, and I found this metal hatch on U-826 that was launched March 1944. It thinks I can see this metal hatch also on very late war U-boat like U-1305 & 1306, but the photo are very poor and impossible to be 100% sure.

[Don Prince]

Hello Mr. Tore and Maciek,


While reviewing the German Diving Regulation Manual I found the following in Section I, Page 5:


"When orders concerning the operation of shut off valves are given only the words "open" and "close" are to be used.  In feedback about the position of the valve only the words "on" and "off" are to be used.  Words such as "shut, tight and opened", are prohibited"


Is this a translation issue, or is this a German Navy Vs Other World Navies?


Regards,
Don_

[tore]

Don.
Orders, particulary on a submarine have to be clear and not to be misunderstood, the various navies have a standard vocabulary  to be used in their own language in order to prevent misunderstandings. It is a challenge to translate a submarine manual into a correct naval wording, as you got to have substantial naval submarine experience in both relevant navies to use the right wordings. In our navy we experienced this difficulty during WW2. Before the war our submarines were designed based on German technology and a substantial part of our submarine wordings derive from the german language. During the German occupation of our country, the Norwegian navy continued to fight the war out from UK, eventually getting British submarines and training. Our submarine language was thus very much "anglofied" and adapted to the Roayl Navys (RN) technology. After 5 years of exile our navy returned to Norway and eventually took over some VIICs, again the manuals were translated based on German naval language into Norwegian UK navy language.  A typical difficult translation is the order for the use of "Untertriebzelle" which is a bit different from the UK submarines "Q" ( quick diving tank).  A german submarine, operating in hostile waters very often have the "Untertriebzelle" filled and used  to overcome the "surface resistance" during a quick diving.
The "Untertriebzelle" was blown at some 10-14 meters to save air. At that depth the order "Aussgleichen" was given and the "Untertriebzelle"s kingston was shut and an inboard venting relieved the pressure in the "Untertriebzelle".  Such procedure was not used in the RN and thus no relevant RN english word exist for the "ausgleichen",  some English translator have made a word for "ausgleichen" calling the order "Express" which for me is a strange word for the procedure. We used " vent Q", meaning shutting the Kingston and open the vent, relieving the air through the silencer into the control room. Sorry for the long story, hopefully it might describe the problem of finding adequate naval words for translating. I guess the similar problems exist between the US and RN english, the worst would be to mix the two languages, to my opinion any manual or technical book on submarines should mention which naval language is used.
In a RN submarine training course it is emphasised, no use of the word close, only shut is to be used.
Tore

[NZSnowman]

Has anyone see a photo(s), or know the pipe diameter of the Exhaust Gas Blowing Manifold? http://www.uboatarchive.net/U-570/U-570Plate16.htm
 
It was tight the first time I added the Manifold, but now after adding the Vent valve for MB & RFO 4 Tank (Stb), I would not say not tight no more, I almost look imposable

[NZSnowman]

Tore, I imagine the drain valves for the piping of the MB & RFO tanks 2 and 4 will be at the lowest point? http://www.uboatarchive.net/U-570/U-570Plate16.htm (valve 'm')

Plus, any idea that it may look like?

[tore]

Simon.
I guess placing the ventduct draining valves close to the gatevalves would be OK. I don`t have any images of same but I think the look would be pretty much like the drainvalves on the outboard exhaust cooling system (silencer) which I presume you have drawn previously.

Tore

[Don Prince]

Hello Mr. Tore,


Are the dual fuel oil filters mounted on the maneuvering panel on the GW Diesel engine the last filters before the fuel oil injection pumps.  I would think so, but I guess I need to consult the expert...


Regards,
Don_

[tore]

Don.
I am afraid not, after the dual fuelfilters you have a knifefilter placed between cyl 1 and 2  just behind the HP fuelpumps. From this filter you have a drain to the dirty fueloil container placed next to the crankcase cover 1. See image below.
Tore

[Don Prince]

Hello Mr. Tore,


Do you know how often the duel fuel oil filters were replaced?  They seem to be a pre-filter for the knife canister fuel filter which can drain its contaminant...


The fuel oil cleaning stages are as follows:


1. the gravity tank (contaminant separation and drainage)
2. the dual filters (replaceable cartridges)
3. the knife canister filter (contaminant drainage)


and finally to the 6 fuel oil injection pumps.


Regards,
Don_

[tore]

Don.
I don`t think the fuelfilters were replaced like disposable paper inserts, only cleaned. The double filter allowed one filter to be in operation while the other filter was cleaned. I cannot remember the exact frequency of cleaning.
Tore   

[tore]

Don.
May be more complete fuelcleaning stages would be as indicated on plate 9 where the filters in the supply lines to fuel bunkertank and the day- (setling)tanks are indicated.
The system plan 9 might be a bit confusing as they have not used a GW arrangement but the fuelpipe arrangement of a MAN engine having the engineattached fuel supplypump and filters placed aft. The final knifefilter in the supply pipe to the HP fuelpumps is not shown.
Tore

[tore]

Fuel filters.
In order not to create confusion it might be good to mention that the first filters in the fuelling pipe were not really filters but mainly strainers having a coarse mesh basket. We used to call it the nuts and bolts filter. Sometimes you could really be astonished as to what some fuelling stations could "supply" and the nuts and bolts filter really caught nuts and bolts.
Tore

[Don Prince]

Hello Mr. Tore,


I believe the diesel engineer is facing the maneuvering panel and the stern of the U-Boat with either diesel engine; GW or MAN.



The last drawing has me slightly confused...  Plan 9 shows the cap and the fuel oil loading connection which is on the port side of the U-Boat.  Your Plan 9 photo inserts seem to indicate the loading strainer/filter is located on the forward starboard side of U-995 against the bulkhead, although close to the diesel engine room walk-way???


Regards,
Don_ 

[tore]

Don.
I agree with you it seems confusing, as you have two fillingpipes on each side of the engineroom door. May be we should not focus on the placing of the pipe on pipescheme. Below I have tried to indicate the system. The port hullvalve and strainer is for luboil bunkering. High up on the port side of the engineroom door you may see the plate on the strainercasing (difficult to read)  but seems to be mot. oelfilter (motoroelfilter) English "motoroilfilter". If the filter was a fuel filter the sign would read Trieboel, german for fueloil. Allthough the sign is doubtful I cannot make the nameplate read Trieboel. As the spare electric driven luboilpump can be used as a fueltransferpump, the fuel pipescheme shows a connection to the luboilsystem, however when fuelling, the shore fueldelivery usually had sufficent pressure to force out the compensatingwater and this pump was normally seldom used as fuel transfer pump when fuelling. I guess the fuel intake and strainer is on the starboard side having a short crossoverpipe from the strainer under the floorplating, going under the engineroom doorstep to the fuledistribution chest under the writing desk on port side.
I have tried to put up the idea on the sketch below.
Tore

[Don Prince]

Hello Mr. Tore,


If water got into the lube oil system/collection tank 1 or 2 through the piston rings...  Was there a drain cock that would allow you to drain the contaminating water from those tanks?

on second thought, after looking at Simon's drawing of those tanks, I don't believe there are any drain cocks for those 2 tanks...  if water got into one of those tanks, then how did you get the water out???


Possibly a access cap at the top to get access to the tank contents, and then use a hand pump with a flexible hose to evacuate the water???

Regards,
Don_

[tore]

Don.
When the Germans removed the luboil sentrifuges of the VIICs they installed under the floorplating large filters with water drain , I guess something like my image below. In addition they kept the handpump system shown on my 2. image below. As you can see when the lubeoil settled in the system tanks, water would be collected in the bottom of the tanks and could be pumped out by the handpump on the aft port engineroom bulkhead and discharged either to the dirty oiltank or overboard. The main problem was that in some rare cases the lubeoil emulsified and the water integrated in the oil, making a homogenius mixture with the oil and impossible to separate. In such cases you had to change the oil completely. It happened to me once.
Tore

[Don Prince]

Hello Mr. Tore,


Do you have this image without markings?  Also, I believe valve "C" is in the shadows below.  Do you have a photo without the dark shadow? Was the lube oil hand pump on the aft Stb side?


Question - When you had the lube oil to emulsify; did you have to shutdown the diesel engine on that side? Was the results damage to the bearing journals, and most other moving parts? Or was you able to dump the emulsified LO and pump uncontaminated LO in to recover the engine?


Regards,
Don_

[tore]

Don.
I don`t have the same photo, but almost a simular taken by falo as shown below. The handpump is on port side aft engineroombulkhead.
 In answer of your emsulsify question. Yes we had to shut down the engine immediately and did not have any dammages. We limped back to the base on one engine. And pumped the contaminated oil ashore.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you for all your help...  One more question - was the lube oil purifying centrifuge pump located near the forward diesel room bulkhead on the starboard side of the early U-Boats?


Regards,
Don_

[tore]

Don.
I never saw the luboil centrifuge, but I assume it was placed somewhere up front of the engines.  It was possibly an unit where the pumps and valves were intergrated in a fairly small module.
Tore

[Don Prince]

Hello Mr. Tore,

These two photos make me believe it was on the starboard side because if the white vertical tubes in back of the purifier...   What do you think?


Regards,
Don_

[SnakeDoc]

Hi Gentlemen,

Don, I believe that purifier was located in the port-forward corner of Diesel engine room.
At the attached photo you can see the British sailor operating stb engine (of HMS Graph).
As you can see, he stands rather freely.
On the other photo:


you can see the port engine. In the bottom-right corner of the photo you can see the rounded cover of some device
(which - I believe - is not present in the stb corner). It can be the top of the vertical cylinder, the part of purifier, also
visible on the photo of the device from U 505.

--
Regards
Maciek

[tore]

Don.
The white purfyer on your image seems to me to be an installation on a merchant vessel, definitely not on a VIIC, but could indicate how a centrifuge module would look like.
Tore

[SnakeDoc]

Tore,

The white purfyer on your image seems to me to be an installation on a merchant vessel, definitely not on a VIIC, but could indicate how a centrifuge module would look like.

The white purifier is installed in the U 505 engine room.

--
Regards
Maciek

[tore]

Maciek.
I guess you found it. The device encircled in red would probably be the luboil purifier. On the museum U 995 this equipment is not fitted. Instead you have a horizontal electric waterpump which I guess supply hot seawater to the galley and other sanitary seawater systems.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,


I don't believe I came up with the photo of the White Purifier that I posted.  However, after doing some searching through my photos scattered between two hard drives (I need to organize this mess!!!), I found a photo of U-505 which seems to indicate the White Purifier belongs to U-505.  I have posted the photo below...  What do you all think about my theory?


Is the gray item close to the bulkhead a electric pump, or the electric water heater that was part of the LO Purifying system.  If that is not the electric water, then where is it on this image of U-505?


Regards,
Don_

[SnakeDoc]

Don,


the purifier for sure belongs to U 505. Here is the link to virtual tour, where you can see it (you have to have QuickTime plugin installed):
http://archive.msichicago.org/exhibit/U505/virtualtour/vr_tour/movie_diesel.html


--
Regards
Maciek

[Don Prince]

Hello Mr. Tore and Maciek,


I just had to understand how the lube oil purifier worked and why we needed the hot water heater.  I understand the reason for the preheating of the lube oil is to assist in separating the water already in the lube oil besides the contaminants. The reason for the electric water heater is for cleaning the centrifuge bowel of sludge that has collected on the sides of the internal bowel.  I found a video that does an excellent job of explaining how the process works with a modern centrifuge. 


https://www.youtube.com/watch?v=00eVuhB7aTQ


However, the centrifuge in the U-Boats was designed in the 1930's and they didn't have the computerized control unit ti initiate the various cycles, but I bet there was some type of control switch or valve where this was done manually.


Comments?


Regards,
Don_

[tore]

Don.
The 1930 marine technology was not so automated as todays. The separators as we called it, had to be cleaned manually and I assume the VIIC separators was cleaned manually as well.
Tore

[Don Prince]

Hello Mr. Tore,


The separator was designed by "Ramesohl and Schmidt, Westfalia., Oelde


GEA Westfalia Separator Group GmbH with head office in Oelde, Westphalia is a German manufacturer of separators and decanters which is affiliated to the GEA Group. The company develops procedures and processes for the mechanical clarification and separation of liquids for the food industry, chemicals, pharmaceuticals, biotechnology, energy, shipping and environmental technology.



1931–1940


In 1931 the company presented the first self-cleaning separator. Co-founder Franz Schmidt died on 18. March 1937. In 1940 the turnover surpassed the 10 million Reichsmark limit for the first time.


Patent DE470723C Filing date Jun 7, 1925 - Publication date Jan 25, 1929

Standing fluid centrifugal drum with upper supply and removal of the material to be centrifuged by axial pipes

I found this on the internet,
 
Regards,
Don_

[Don Prince]

Hello Mr. Tore,


I updated pages 140 - 143 in Skizzenbuch and posted the latest version in dropbox.  When you have time would you please review those pages and let me know what you think...  This version of Skizzenbuch has had a lot of updates and superficial changes; like moving pages to make things more logical in sequence.


Kind regards,
Don_

[SnakeDoc]

Don,


according to British report on HMS Graph:

Lubricating Oil Separator, Type 2 LHD 2/20
Capacity:   300 litres lub. oil/hour at 1 atm. at a speed of 1350/1,750 r.p.m. (66 galls./hr. at 15 lb./sq. in.).
Makers: Ramesohl and Schmidt, Westfalia, Oelde.
Motor Makers: Werdohler Pumpenfabrik, Werdohl, I/W Paul Hillebrand G.M.B.H.

In the type VIIC manual there is a chapter that describes the purifier:
An electrically driven purifier with a capacity of 250 liters/hour is provided in the diesel engine room for purifying dirty lubricating oil.  The purifier is equipped with an electrical oil pre-heater and a hot water pre-heater.  Directly coupled with the drive shaft are the pure oil and dirty oil feed pumps.  These two geared pumps arranged one after the other.  The attached dirty oil pump sucks the contaminated oil from the lubricating oil collecting tanks and passes it over the oil pre-heater into the lubricating oil purifier.  The cleaned oil is then pumped by the pure oil pump.
The waste water from the oil purifying process drains into the bilge.  A hot water pre-heater is provided for better cleaning of engine lubricating oil.

The correct manufacture name is: Ramesohl & Schmidt A.G., Ölde i. Westfalen.


Regards
Maciek

[tore]

Don.
I just had a brief look at your latest Skizzenbuch new text starting from page 141. On page 142 you are showing the lube oil cooling system naming the coolers luboilcannister filters. On this drawing the filters are not shown. I guess I made a mistake when I commented on your mixing up the double  fuelfilters with the luboilfilter posting the wrong image of Simons luboil system. Down below is a right image from Simon and the traditional lubeoil scheme where I have tried to indicate the positions of the lubeoil filters. I guess you should reduce the dimension somewhat down to say 200 mm  diameter. The filters are usually placed before the coolers as you have less resistance when the oil is warm. To show all the systems on top of each other makes it difficult  to read and understand and might be confusing. Reverting hopefully tomorrow.
Tore

[Don Prince]

Hello Mr. Tore,


There are two electric piston pumps located on the right top and bottom of Simon's drawing (look like round circles). I believe these are the diesel engine water cooling pumps.  If one water cooling pump fails, then can 1 water cooling pump cool both diesel engines?  It looks like they could function in that way...


The basket type filter on the initial lube oil loading line serves to catch the nuts and bolts.  So, did they replace the 2 basket type filters with 2 knife type filters that were placed very close to the valve chest?

Does the labeling look correct on the attached photo?  What is the large red cap for at the bottom of the photo?

Regards,
Don_ 

[tore]

Don.
In order not to get confused I take one question at the time. The "round circles" on Simons image are not electric driven pistonpumps, but the well known port screw "Imo" spareluboil/ fueltransfer pump and the other the spare electric driven seawater centrifugal pumps as indicated on my image below. Please note that the original seacoolingwater scheme has a mistake as the suction for the electric driven seawaterpump has a suction connecion to the main crossover seawaterpipe . The pump can indeed be used as spare coolingwaterpump for both engines.
Tore.

[tore]

Don.
The attached piston coolingwater pumps are located well below the floorplates and are not easy to see. Below is an image of the double pistonpump driven off a gearwhweel on the crankshaft just aft of the vibrationdamper on the front of the engine.
Tore

[tore]

Don.
 Basket strainers. If you mean the lubeoil filter before the lubeoilcoolers I don`t think they are replacement. In the old systemplan you`ll see there is a differential manometer to survey the pressuredrop over the filter, so I guess it could be classified as the main lubeoilfilter.
Tore

[Don Prince]

Hello Mr. Tore,


These filters and pumps are really getting to me.


1. I now understand the water cooling pumps (location) are an integral part of the diesel engine.
2. I now understand the lube oil pumps (location) are also a integral part of the diesel engine.
3. Is there a way to disable the lube oil pump mechanically so it's not running when you want to change it out?
4. Did you change out a lube oil pump while the diesel engine was running?
5. If so, is the lube oil pump configured in a by-passed, or isolated mode, so it may be changed and not get pressurized lube oil feed from the aux. Lube oil pump if it's supplying lube oil to the running engine?
6. What are those 2 electric lumps for in the opposite corners of the forward bulkhead used for?
7. If a water cooling pump fails can it be replaced on a war patrol?
8. Is there any possible valve chest switching to allow one pump to supply cooling water to both diesel engines?


I should know or be able to figure this out this stuff on my own, but I just don't want to get this wrong...


Regards,
Don_

[tore]

Don.
Labeling photo. I am afraid you have to correct the labeling. Below you`ll find my corrections, but you really have to go into the lubeoilsystem to have a correct understanding.
Tore

[tore]

Don, your last questions. Again you have to study the whole lubeoilsystem to have a complete understanding as there are many options to operate the system. You can indeed run the main engine disabeling the attached coolingwaterpumps, I have done that myshelf when the port engine coolingwaterpump broke down. If the drive of the pumps are mechanically OK, you can operate the valves so you are able to connect one of the systems to the other f.i. operate the port engines attached pump to serve the stb as well or to operate the system by the electric centrifugal seawaterpump. Normally you dont`carry a complete pump with drive and casing as spare due to spaceproblems, we had to get a new from base as the piston conrod got loose, smasing the casing. You cannot be sure to be able to continue a war patrol on two engines if you have a brake down, it all depends on the collateral damage, that is the drawbackof attached auxilliaries.

Tore 

[tore]

Don.
I am not sure if I understand your question 6. about two electric lumps?
Tore

[SnakeDoc]

Hi Don,

6. What are those 2 electric lumps for in the opposite corners of the forward bulkhead used for?

If you mean electric pumps in the forward port and forward stb corner of the Diesel engine room, the one in the port corner is auxiliary/emergency lubricating oil pump (and transfer fuel oil pump). This pump was used to force lubricating oil through all friction surfaces of the engine, before it is started up (and when the individual lubricating oil pump driven from the crank shaft is not running). Of course, it was also used when the crank shaft driven pump is out of order.
When used as fuel oil transfer pump, this pump transfers fuel from external fuel oil tanks (tankers, depot ships and so on) to the boat's fuel oil tanks.


In the stb corner is the auxiliary cooling water pump, used when the individual cooling pumps driven from crank shafts are out of order and to cool down the diesel engines after they were stopped (and when individual cooling pumps also were not working).


These pumps are vertical shaft, centrifugal pumps. The parts visible above deck plating are the electric motors, the pumps themselves are below deck. Such arrangement (similar to all other pumps) is to protect motors from splashes and water (even if pumps are flooded due to high water level in bilges, the motors are safe).


--
Regards
Maciek

[tore]

Done.
I guess I did not answer your question on the atteched luboilpump which is a gearpump. It goes the same way as for the attached piston coolingwater pump. you can remove the pump in case of damage and isolate the pipesystem connected to the pump. In such case you use the electric driven screw lubeoilpump on the port side and direct the oilflow as indicated on my image below shortcutting the attached gearpump.
Tore

[SnakeDoc]

I would like to make some comments to my previous post:

6. What are those 2 electric lumps for in the opposite corners of the forward bulkhead used for?

If you mean electric pumps in the forward port and forward stb corner of the Diesel engine room, the one in the port corner is auxiliary/emergency lubricating oil pump (and transfer fuel oil pump). This pump was used to force lubricating oil through all friction surfaces of the engine, before it is started up (and when the individual lubricating oil pump driven from the crank shaft is not running). Of course, it was also used when the crank shaft driven pump is out of order.
When used as fuel oil transfer pump, this pump transfers fuel from external fuel oil tanks (tankers, depot ships and so on) to the boat's fuel oil tanks.

One more use: taking the lubricating oil into the boat's tanks.

These pumps are vertical shaft, centrifugal pumps. The parts visible above deck plating are the electric motors, the pumps themselves are below deck. Such arrangement (similar to all other pumps) is to protect motors from splashes and water (even if pumps are flooded due to high water level in bilges, the motors are safe).

The auxiliary lubrication pump is not centrifugal type (as I have written before) but worm type pump, with one main rotor (driven by electric motor) and one auxiliary rotor (rotated in the opposite direction), both in vertical arrangement. The oil is pumped up from the bottom.



The auxiliary cooling pump is centrifugal type pump, not self-suction, i.e. it has to be flooded to work (but it is not a problem, because the water level is always above the pump).


--
Regards
Maciek

[SnakeDoc]

Regarding the previous post about filters, I have attached some images of the filters (not necessarily used on U-Boats, but from that period).


--
Regards
Maciek

[Don Prince]

Hello Mr. Tore,

Page 123 - The Büchi turbo charger was never used at lower loads; the tuning of the exhaust/inlet cams was adapted to higher exhaust pressure even on U-Boats without a schnorchel.

1. Should that be the roots supercharger was never used at lower loads?
2. I thought the Büchi turbo charger was always engaged on the MAN diesel engines
3. Did the Germans tune the exhaust/inlet cams to adapt to higher exhaust pressure for schnorchelling?
4. I believe a MAN diesel engine would have the Büchi turbo charger engaged while schnorchelling, but I'm not sure that a GW Diesel engine would have the Roots supercharger engaged while schnorchelling because of the 6 knots speed restriction (stress/snap the schnorchel mast).

Regards,
Don_

[tore]

Don.
I guess it is a misunderstanding stating the Buchi turbocharging system was never used at lower loads. This relates to the Roots blower. The Roots blower required a lot of energy to operate and did not contributed to a higher efficiency of the GW diesel to compensate for the higher power requirement,  hence you only increased the fuelconsumption, so you disengaged the blower at lower loads. The Roots blower was merely a device to boost the max. power of the engine when higher output was required. The MAN turbocharger utilised the energy in the exhaustgases thus using the waste heat energy to operate and hence contributed to a general higher efficiency e.g. lower fuelconsumption and could not be disengaged.
On the non reversible GW engines you had only one set of valvecams. I don`t know for sure but assume on the MAN turbocharged engine you possibly had two sets of cams using adopted cams on the reversing shaft, this might be due to the exhaust gas turbine.
When schnorcheling you primarily was charging the batteries, using low speed propulsion on E motors  as we had speed restrictions.
Tore

[karel]

Hi Tore.


Can you tell me  how did the crew know when the boat was in balance? I am looking trough panorama pictures and cannot seem to find any indicators that would show this kind of information.

[tore]

Karel.
Getting the submarine in balance can be many things, in fact a VIIC submarine was very seldom in 100% ballance as temperature, watersalininty and the daily life of 46 men altered the parameters all the time. The first step would be to calculate the estimated deadweight and adjust the regulating tanks accordingly prior to the test diving. At the first testdiving you checked how close your calculation was and made adjustment by the regulating tanks checking the Papenberg depth gauge. The alongship trim was checked by the inclinometer and adjusted by the forward and aft trimtanks, and a possible atwartship list was checked by a simple inclinometer weigth hanging on the atwart bulkhead and adjust the port and starboard regulatingtanks. Down below I have made an image of the systems. Next to the Papenberg column we had an image of the periscope so you could see the position of same relative to the seawatersurface. On some submarines you even had an image of the schnorchelmast top relative to the seasurface. You very seldom was "hanging" motionless in perfect ballance, mostly the balance ( within limits) was kept dynamically by speed and hydroplanes.
Tore

[SnakeDoc]

Hi Karel,

check this thread.

--
Regards
Maciek

[Don Prince]

Hello Mr. Tore and All,


Does anybody have good photos of the Aux Water Cooling Pump/Transfer Pump in the diesel room, and the Water Cooling Pump for the e-motor bearings and thrust bearing cooling? Mine are not too good...


Regards,
Don_

[SnakeDoc]

Hi Don,

Does anybody have good photos of the Aux Water Cooling Pump/Transfer Pump in the diesel room, and the Water Cooling Pump for the e-motor bearings and thrust bearing cooling? Mine are not too good...

Check your mailbox. The electrically driven cooling water pump in the aft torpedo room (behind the main switchboard port) was also used (primary) to cooling E-motors (or to be more strict, cooling the air used to cooling the motors) and cooling (and lubricating) the shaft strut bearings.


--
Regards
Maciek

[tore]

Don.
I guess you mean the aux. coolingwater pump on stb side, forward end of the main engine. Which is a vertical centrifugal pump of Odesse, Oscherleben type G 80/180 capacity 800 l/min against 3 kg/cm2. Unfortunately I have no photo of same. Might be you are able to find an image on the net.
The centrifugal coolingwaterpump in the e-room is of a different type than the stb aux. coolingwaterpump in the engine room  as it operate against a higher head, 12 kg/cm2. The reason is cooling of the propeller shaft seals,main thrustbearings , aircoolers and bearings of the E-motors/generators. Make Klein, Schanzlin & Becker. The pump is on the image below.
The aux. luboil/ fuel transferpump is of a vertical screw pump make Leistritz, Nuremberg. Capacity 38m3 against 50m WC. Suction 5m WC.
The lubeoil system plate 14 has a wrong icon for the aux lubeoil/ fueltransferpump marked as a centrifugal pump, below I have made a correction.The reason for using a screwpump for the lubeoil/ fuel is a centrifugal pump create cavitation and gas bubbles in the oil. Most probably the screw pump would be a triple screwpump having one center drive spindle and two outer idle.. The manufacturer is still in existence and on their webside you`ll find images of their screwpumps, they still make pumps for submarines.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,


Do you all have a better photo of the auxiliary water cooling pump then what I have? Perhaps a little wider?
... And it is a centrifugal type pump correct? Also, what is that drive shaft above the pump?

Regards,
Don_

[tore]

Don.
The aux. coolingwater pump is, as I stated, a vertical centrifugal pump of make Odesse, Oscherleben, type G 80/180 with a capaciy of 800 l/min against a head of 3 kg/cm2.
The driveshaft  shown on the top of your image is the mechanical driveshaft for the hand operation of the aft hydroplanes.
Kindly note the original coolingwater plan 13 has a mistake omitting the suction connection to the crossover pipe both for the stb engine attached piston coolingwater pump and the suction for the aux.centrifugal pump. I have corrected the plan 13 below.
Tore

[Don Prince]

OK, I will make sure it is fixed on my Plan 13...  Do you have a wider photo of the aux water cooling pump that shows some of the engine and the bulkhead?


Regards,
Don_

[Don Prince]

Hello Mr. Tore,


I have a general question about the lube oil with sea water contamination... From what I understand the intrusion path for the sea water is through a leaking exhaust valve during a dive (lets stipulate one side). If the lube oil collection tank has sea water at the bottom, then that means the sea water passed through the piston rings, the engine crank case. and finally ended up in the lube oil collection tank.


1. After blowing out the sea water from the cylinders, do you make any other checks before starting the diesel engine?
2. I believe before starting the diesel engine you would use the aux. lube oil pump to press oil through the diesel engine.  Perhaps the pressed lube oil will force any sea water from the crank case (I don't believe there would be any oil emulsification with that procedure)?
3. So, at this point the sea water would be pumped into that diesel engine's collection tank.
4. How did you know if there was sea water in that engine's collection tank, was there a procedure to check things out once it was determined that water was in the cylinders? or even still remaining in the diesel engine's crank case?
5. Could there ever be an issue with sea water below a good set of the piston rings that passed a compression test?


What I'm attempting to understand is how the diesel engine mechanic recovers form this situation...
6. He could start up the good diesel engine, but the problem side needs his love and attention.
7. How would you resolve the problem on the contaminated side?


Kind regards,
Don

[tore]

Don.
Before the automation of the engineroom the engineers used hands, eyes, ears and noses to detect irregularities of the engines. Water in the lubeoil  as well as fuel might enter the system in many ways. The most common was the leaking of the main hull exhaustvalves. Leaking pipes in coolers/heaters and some times in watercooled exhaustvalves in the cylinder cover. Each leakage gave different indications. It would be impossible to list up all the different aspects, that`s why you got to have experienced engineers. F.inst. waterleakage in the exhaustvalve casing would be seen on the colour and temperature of the exhaustgas, water in the lubeoil could be detected by condensation droplets in the crankcase. When the oil settled in the systemtanks the hand pump could be used to have a visual check by looking on the discharge in the funnel.
You always would run the engines on air ( no fuel injection) prior to starting. Emulsification happens over some time, we checked the oil visually and when we saw sign of emulsification, the oil turned gray, became like mayonaise, we had to drain it from the system. This did not happen all the time, I experience this once in three years.
Piston rings can have a water leakage even if a compression test is OK. As piston rings have a split (gap) water can pass when the engine is not in operation. The main tigthening of the pistonrings do not come from the initial spring effect but from combustionpressure and compressionpressure leaking into the pistonring groves at the back side of the compressionrings, forcing the pistonring towards the cylinder wall.
Whenever the engine would be turned by air or manually you would start the  aux.lubeoilpump to protect the bearings.
The diesel engineers have many means to detect watercontamiation of the lubeoil, experience is the key and not everything can be put down on paper.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you for the detailed info on my questions about sea water in the lube oil...  It looks like the bottom line is when this happens and there is some emulsification, then it's time to end the war patron and head back to your home port for some needed repairs!


From what I understand, if there is a failure of the attached gear driven lube oil, or fuel oil pumps, then the aux pump may be activated if the situation requires both diesel engines running. Since these are driven by the diesel engine with metal gears pumping the oil, then what generally would be the failure mechanism? Once the diesel engine is shut down, then the mechanic may replace either pump, is that correct?


Regards,
Don_

[tore]

Don.
Failure of attached pumps might be any thing. Normally a gearpump is very reliable, however on the direct reversible engines  the attached pumps did reverse as well and you got to have intricate valve systems to make the pumps work running astern. These complications are only related to the gearpumps like the fuel and lubeoil pumps and not the reciprocating pumps like the piston coolingwaterpumps. so you might experience trouble with the valvesystem. On the front of the engines you`ll see the pipesystems for both the fuel and luboil where you can operate the systems alternatively shortcutting filtes and pumps by shutting cocks and valves.
Usually you could repare or exchange the pump easy, the nightmare would be to have a major damage to drive from the crankshaft. However every system has many alternative operations and you would almost always find an emergency solution thanks to the flexibility of the systems.
Tore

[Don Prince]

Hello Mr. Tore,


You would only change-out a failed attached gear pump when the diesel engine is shut down, is that correct?


Regards,
Don_

[Don Prince]

Hello again Mr. Tore,


I have come to realize that this engine lubricating system is so complex with many variables... I was studying the hand pump for manually pressing lube oil through a selected diesel engine. I don't know why they would use a hand pump when they have that huge aux. lube oil pump sitting on the port side?


1. I have colored in the pipes for when the hand pump is being used to press USED lube oil to a diesel engine (BLUE - is suction, and RED - is pressure). Valve "a" is open to allow the hand pumping to draw oil from the selected collection tank, and valve "c2" must be shut because we don't to draw CLEAN oil from the storage bunkers. Then through the hand pump, and valve "n" is shut because we don't want the oil going to the tank for filling oil cans, and finally valve "b" is open to press the lube oil to the diesel engines.


- It looks like that works OK (YES or NO)?


2. I have also colored in the pipes for when they want to pump CLEAN lube oil to the tank for filling oil cans (GREEN - is suction, and YELLOW is Pressure). In this instance I think valve "c2" must have 3 positions (left - off - Right). The left or right positions permit the selection of a CLEAN oil storage tanks, and the "off" position relates to the above procedure when pressing oil to the diesel engine. Then through the hand pump, and valve "b" must be shut to direct the CLEAN oil into the tank for the oil cans.


- It looks like that works OK (YES or NO)?


The only thing I question is Valve "c2" because it looks like an "L" type valve, but I believe it has to have an 'OFF" position. Also, it looks like there is a possibility to draw USED oil to the tank for the oil cans by having valve "c2" shut and valve "a" open?


- Did they ever want USED oil for the oil cans?


Drawing attached...


Regards,
Don_

[Don Prince]

Hello Mr. Tore and Maciek,


I believe I resolved the problem of a photo of the water cooling pump on the starboard side.  It's really impossible to get a good wide angle shot of a pump that's a bit down below the diesel engine room floor and large horizontal pump blocking the view.  So, I improvised...


Regards,
Don_

[tore]

Hello Mr. Tore,


You would only change-out a failed attached gear pump when the diesel engine is shut down, is that correct?


Regards,
Don_

Don, yes.
Tore

[tore]

Don.
The large aux. lubeoil pump would require electricity which in spite of batteries was not always available, hence a small handpump to handle small quantities during maintenance work.
Q 1. It works for drawing ( green) fresh luboil in small quantities from port lubeoil storagetank the way cock2 is positioned. Would probably be used for filling the small daytank.
Q 2. It works. But remember the pipes are small, low capacities. it would probably be used for maintenance work on the engines like turning the engine manually.
Cock "n" to the lubeoil daytank could be shut. Generally fresh oil was used for the oilcans but if you would need larger quantities for maintenance work you would use used oil, but not contaminating the daytank with such oil. Indeed you could draw lubeoil in small quantities from the sumptank of each engine, remember the engines are of the dry sump type, but if you would take a sample of the luboil in the system of a relevant engine, you could use the handpump.
As I have stated before there are numerous ways to operate the systems describing one on the cost of others might be confusing and should be mentioned as an example of many.
Tore.

[karel]

Tore and Maciek. Thank you for answering my question.

I have another one about rudder gauge. I attached the screenshot and you can see there are red lines marked at number 25.  https://www.dropbox.com/s/hijz49wot1x8y4a/rudder.jpg?dl=0
Can you tell me what this means? If i had to guess then rudder max turn angle was 25 degrees?

[SnakeDoc]

Hi Karel,

I have another one about rudder gauge. I attached the screenshot and you can see there are red lines marked at number 25.  https://www.dropbox.com/s/hijz49wot1x8y4a/rudder.jpg?dl=0
Can you tell me what this means? If i had to guess then rudder max turn angle was 25 degrees?

 The rudder maximum deflection is 25° when electrically driven and 35° when manually driven.

--
Regards
Maciek

[karel]

Hi Maciek. Thank you. This makes sense.
 
Can you tell me where the manual rudder was located?  In the aft torpedo room?

[Don Prince]

Hello Mr. Tore,


Last question on the engines and oil, How do you turn those huge engines over manually?

I think I going to bed...  It's 5:05 AM!  I'm like a vampire, I sleep all day and work all might!

Regards,
Don_

[SnakeDoc]

Can you tell me where the manual rudder was located?  In the aft torpedo room?

You are right, the main rudder manual control station is located in the aft torpedo room. There is an hand-wheel provided, which is coupled with the rudder drive shaft. When not used, the control column and hand-wheel is moved to the stowed to the port side (between the electrically driven air-compressor and main switchboard port), as currently on U 995 display (white slanted column and red hand-wheel):


See also this photo from U 570 aft torpedo room.
http://uboatarchive.net/U-570/U-570Photo32.htm
Here, the hand-wheel is detached from the column.


If there was a need to use manual control, the column was moved to the center-ilne, as on this photo from U 505 aft torpedo room:


--
Regards
Maciek

[karel]

Much appreciated Maciek

[Don Prince]

Hello Mr. Tore,


I was reviewing Skizzenbuch and I came across the info on the day tank and the fuel oil system.  We noted that valve "e" had an unusual position that allowed fuel oil to go directly to the attached fuel pump on the diesel engine.


Could it be possible... If the attached fuel pump failed, then the auxiliary lube oil pump could draw fuel oil from a selected fuel oil storage tank. Then fuel oil is directed by valve "e" to the by passed attached fuel oil pump and on to the fuel injectors to fire the cylinders and keep the engine running.


Of course, the attached fuel pump would need to be changed when the engine is shut down.


Does this sound logical?


Image attached.


Regards,
Don_

[tore]

Don.
I guess you should consider the fueltransfersystem independently from the daytank/headertank system. You filled the daytank normally by the compensatingwaterpressure using the head of the compensatingwater tank in the wintergarten casing, thus no use of the electric driven aux.luboil/fuel transferpump. As soon as the day-headertanks were filled the tanks were shut off from the compensatingwatersystem, hence no compensating pressure in the system. Usually one tank was selected  for supply, the other for setling. The daytank in the engine supplymode would generally initiate sufficient natural supplyhead to the attached gearpump. If the attached gearpump failed, the head of the daytank would probably not be sufficent for to overcome the pressuredrop over two filters in series and you would use the compensating system pressure as an emergency substitute for the attached fuelsupplypump. In that case you are shortcutting the day/setlingtanks and have a direct supply connection from the fuelstorage tanks to the dieselengine fuelsystem at the cost of no setlingtank.. Of course you might use the emergency fueltransfer pump as well but as you have to add compensatingwater anyhow I guess that would be superfluous.
Tore

[Don Prince]

Hello Mr. Tore,


I obviously forgot to consider the header tank into the equation in the instance of a fuel pump failure.  That's why I have you as the expert! I didn't realize they turned off the header tank pressure to the internal fuel oil storage tanks on the surface (I only thought they did that when they dived the U-Boat); that would make sense because that would be one less valve to worry about when a dive situation is called for! However, the header pressure to the external tanks in the compensating mode to FBT 2 and FBT 4 can not turned off. (I don't think?).

I need to STOP guessing!



Mr. Tore, I have searched the internet for many hours today and I cannot discover what the head pressure from the fuel oil pump is to the injectors.  If you know the answer to that question, then you can set me straight. It looks like the header pressure can vary depending upon the height of the water in the internal fuel oil storage tanks. So this may affect the head pressure to the injectors as well???  Internal tank 1 has the height level much higher because of the side walls, but Internal tank 2's height is limited to the control room's deck.  Would Internal tank 2 be the only tank to select to by pas the fuel pump if it provided adequate head pressure to the injectors?


Regards,
Don_


PS - I did fine this gem of info...

A standing order states that when using Schnorchel U-boats may only use fuel from the external tanks.  Fuel is pumped from the internal tanks by using diesel cooling water, the pressure varying with the depth of the boat; if the boat is at 14 meters (46 ft.) the pressure is 1.4 atmospheres.  If fuel is pumped from the internal tanks with cooling water at this pressure the tanks are subjected to a pressure greater than that for which they are designed.
 
By approximate and experienced handling, however, ("cracking" the appropriate valve) fuel can be pumped from the internal tanks, but accidents are likely to occur and this may have been the reason for the order.

 

[tore]

Don.
In order not to create confusion I guess you should have a correct understanding of the system. The fueltanks (bunker)are for storage and are seawater compensated from the diesel engine coolingwatersystem. The compensating pressure when the submarine on the surface is obtained by the head of the compensating tank in the wintergarten casing and do not relate to the coolingwaterpressure. When the submarine is submerged, the higher differential pressure in the external fuel storage tanks is still only obtained by the headtank. However if you open the compensating water board valves to the internal tanks you introduce the external ambient sea pressure to the internal tanks which might exceed the designed pressure for the internal fuelstorage tanks. For safety reasons the internal tanks have reliefvalves to prevent damages in such events. You might however, if you are experienced, be able at schnorchelling to crack the compensating water hullvalves so you throttle the pressure within safe limits in the internal fueltanks.
The fuel in the bunkertanks is generally transfered by using the compensating waterpressure, say to the day/setlingtanks in the engineroom. The latter tanks are not watercompensated and thus have a venting into the internal pressure of the submarine. Hence the supply to the gearpump on the main engine is done by the head of the day tank. The attached gearpump purpose is only to supply fuel by a common fuelpipe to the independent HP fuel injection pumps for each cylinder. As you have the double fuel filters on the front of the engine and the knife filter before the supplypipe to the HP pumps, the attached gearpump has to force the fuel through these filters.
Below is an image of the venting pipes of the fuel day/head tanks in the engineroom.
Tore

[Don Prince]

Hello Mr. Tore,


What you stated makes sense and I believe that I grasp your explanation...  The only question I have is does the internal storage tanks (especially Tank 2) have enough head pressure to permit fuel to skip the gravity tank and flow through the valve "e" central passage and supply fuel oil to the engine with a by passed failed pump? The failed pump can no longer draw fuel from the gravity tank, so this flow path does not exists anymore for that pump...


Kind regards,
Don_

[tore]

Normally the attached gearpump has sufficient pressure (some 2 m. wc.)from the daytank head at the suction side to supply the required amount fuel. Storage tank 2 has compensating waterpressure just as the other storagetanks, controlled by the head of the compensating tank in the wintergarten casing as long as the hullvalve for the compensatingwater is open. Surfaced the head in the storage tanks (some 5 m. wc.) would be sufficient to fill the daytanks.
 If the attached gearpump has a failure and had to be short cutted, the head of the daytank is probably not sufficient to force fuel through the filters in the supply pipe to the HP fuelpumps, hence you use the full compensating pressure ( some additional 2.m wc. to the daytankhead) to force the fuel through the fuelfilters and you to use the compensating water head directly to the fuelsupply pipe shortcutting the daytank, a indicated on my image below.
Tore

[Don Prince]

Hello Mr. Tore,


That's what I was looking for, thank you...  After getting a good 7 hours sleep, my head is much clearer now!


I realize that the water column head pressure from the internal fuel tanks is about the same, and the water column head pressure would be less from FBT 2, R 1, and FBT 4 when in the fuel oil configuration.


I was thinking about fuel tank usage and this is how I perceive it would go:
1. R 1 for better/easier full ballast control when diving or at periscope depth
2. FBT 2 and FBT 4 converted to full ballast control, for better fuel economy (less resistance from a deep hull)
3. The Internal tanks in an alternating method as not to disturb the U-Boat's horizontal balance


What do you think?


Regards,
Don_ 

[tore]

Don.
Within limits I agree. However the way the Germans used the VIICs I don`t think they had so many options. Before leaving for a warpatrol they had to store up as much fuel as possible. As previously stated we very seldom used the MBTs for fuel as our strategy was mostly coastal defense, having access to fuelling stations all along the coast.
Tore

[Don Prince]

Hello Mr. Tore,


I know that the clutch may be disengaged between the e-motor and the propeller drive shaft when charging the batteries.  And I remember that the drive shaft break is applied when charging the batteries with that e-motor.  The only thing I have forgotten is why was the break applied?


Regards
Don_

[tore]

Don.
I don`t believe you had to disengage the tail clutch when charging the batteries as we used to top up the batteries while using the diesel for propulsion. Of course the engineers kept an eye on the load of the engines and adjusting the battery charging within proper limits.
When you are running on one engine the drag cause the other propeller to rotate. In the event that you did`t want the motor/ generator  to rotate you had to apply the break.
Tore

[SnakeDoc]

Hi Gentlemen,

Patent DE470723C Filing date Jun 7, 1925 - Publication date Jan 25, 1929

Standing fluid centrifugal drum with upper supply and removal of the material to be centrifuged by axial pipes

I have found the this patent document (in attachment).

I have also attached two others patents that may bring some light to the solutions developed by Ramesohl & Schmidt A.G., Ölde i. Westfalen.

--
Regards
Maciek

[Don Prince]

Hello Mr. Tore,


I believe a full current charge at 1660 amps they just had the diesel connected to the e-motor as a motor-generator, and the prop was disconnected.


However, I believe your answer is correct about stopping prop spin on a side that is not running... (Thanks!)


Regards,
Don_

[SnakeDoc]

Regarding various scenarios when different elements of the fuel oil/lubricating oil/cooling water systems are out of order (based on German manuals):
Lubricating oil:
normal operation: attached lubricating oil pump forces oil through the lubricating oil distribution box, lubricating oil cooler to the engine.
attached lubricating oil pump out of order: connect together lubricating oil systems of both engines at the distribution box. Connect together both lubricating oil collection tanks.
both attached lubricating oil pumps out of order: force the lubricating oil (by means of the auxiliary lubricating oil pump) from both lubricating oil collection tanks through the distribution box to the engines.
lubricating oil cooler out of order: bypass damaged cooler, both attached lubricating oil pumps force the oil through the working cooler

Cooling water:
normal operation: attached cooling water pumps force the outboard sea water through the distribution box, lubricating oil coolers, engines, blowers to the exhaust manifolds.
attached cooling water out of order: both engines are cooled by one attached cooling water pump.
cooling by auxiliary cool water pump: when both attached cooling water pumps out of order.
cooling down by hand pump: when the engines are shut down after running under high load (i.e. during alarm diving), it is necessary to cool them down by means of the hand pump
circulating the water by hand pump: used to circulate the water with anti-corrosion agent through the cooling water system (outboard sea water intake and outlet have to be shut).

Fuel oil:
taking the fuel oil by means of the external (depot fuel oil) pump: through the fuel oil hose, fuel oil meter and fuel oil transfer system to the fuel oil tanks.
taking the fuel oil by means of the auxiliary lubricating oil: the auxiliary lubricating oil pump can be used as fuel oil transfer pump, pumping the fuel through the fuel oil meter to the fuel tanks.
giving the fuel oil by means of the auxiliary lubricating oil: outboard, from the fuel oil tanks, through the fuel oil meter.
filling the fuel oil tank from the fuel oil tanks: by means of the pressurized cooling water
transferring the fuel oil from main ballast and fuel oil tank to the internal fuel oil tank by means of the auxiliary lubricating oil pump:
transferring the fuel oil from the internal fuel oil tank to  main ballast and fuel oil tank by means of the auxiliary lubricating oil pump:
draining the internal fuel oil tank by means of the trimming pump: the trimming pump can be used to drain the internal fuel oil tank by means of the auxiliary hose connection between the fuel oil compensating system and the pump.
draining the internal fuel oil tank by means of the cooling water hand pump: by means of the auxiliary hose connection between the pump and compensating system
draining the internal fuel oil tank by means of the auxiliary cooling water pump: by means of the auxiliary hose connection between the pump and compensating system


--
Regards
Maciek

[Don Prince]

Great info Maciek...


Hello Mr. Tore,


I found the following in the British U-570 Report... Is this correct?



Circulating Water System
 
   
The circulating water pumps are fitted in pairs at the forward ends of each engine.  They are engine driven from the crankshafts.
 
   
2.  The main inlets are fitted at each side of the starting platform and are in duplicate, the inner valve being a sluice.  There is a common suction to each pair of pumps and there is also a common delivery pipe and a common air vessel.  A relief valve is fitted in each discharge, the water from this relief passing to the bilge.
 
   
3.  A throttle valve is fitted in the suction side in order to regulate the amount of water pumped.


Generally, was the diesel attached water pump replaceable at sea or was it a depot job?
Regards,
Don_

[tore]

Don.
Below is an image of the attached double coolingwater pumps driven from the front side of the crankshaft. As you see the pumps are placed well below the floorplating and are not easy accessible. When we had the broken coolingwater pump, we were able to inspect the collateral damage and change the parts by the engineroom crew.
Tore

[Don Prince]

Hello Mr Tore,


OK, its a double piston pump not actually two water pumps... The word "pairs" confused me!
If one piston or one set on valves fail will the pump still be functional enough to cool the engine?

Don_

[tore]

Don.
I guess it depends on the failure as you have common discharge and no isolating shut off and common gearwheel pto on the crankshaft. I guess the capacity of the pump would be OK, but I would prefer to shut of the damaged pump completely and using other cooling alternatives.
Tore

[Don Prince]

Hi Maciek,

I'm having some problems with the Fuel Oil: Info...

Using the Auxiliary lubricating oil pump to transfer fuel oil from one tank to another?  If you are taking fuel oil from a saddle tank, then the fuel oil goes through the tank selection valve chest then to the fuel oil valve chest and finally to the aux lubrication oil pump...  Now, what path does the auxiliary lubrication pump use to get the fuel oil back to the internal fuel oil tank? It looks like the tank selection valve chest is a one-way street, unless depot refueling where fuel only flows in the opposite direction?

Draining the internal fuel oil tanks? That U-Boat ain't gonna dive?

Regards,
Don_

[tore]

Don.
Pumping fuel from the fuel/ballast saddletanks might be a problem if you use the internal fuel system as a suction system. The reason would be that the deliverypipe, now acting suction pipe, ends on top of the saddletanks to prevent watercontamination. Without a compensating waterpressure the aux fuelpump suctionpipe would end up in the air.  If for some reason you would have to transfer fuel from the saddletanks in fuelconfiguration by the aux.fueltransferpump you would use a hoseconnection possibly via the man hole.
Tore

[SnakeDoc]

Hi Don,

Using the Auxiliary lubricating oil pump to transfer fuel oil from one tank to another?  If you are taking fuel oil from a saddle tank, then the fuel oil goes through the tank selection valve chest then to the fuel oil valve chest and finally to the aux lubrication oil pump...  Now, what path does the auxiliary lubrication pump use to get the fuel oil back to the internal fuel oil tank? It looks like the tank selection valve chest is a one-way street, unless depot refueling where fuel only flows in the opposite direction?

I have to correct myself.

Fuel oil:
[...]transferring the fuel oil from main ballast and fuel oil tank to the internal fuel oil tank by means of the auxiliary lubricating oil pump:
transferring the fuel oil from the internal fuel oil tank to  main ballast and fuel oil tank by means of the auxiliary lubricating oil pump:
[...]

These two lines should look as follows:
transferring the fuel oil from saddle tanks to the internal fuel oil tanks by means of the auxiliary lubricating oil pump: the pump takes the fuel oil from the saddle tanks through the fuel oil transfer system and pumps it through hose connection of the fuel oil valve chest (I guess b1 or b2) to the internal fuel oil tank (I guess the hose connected the fuel oil valve chest and the compensating system of internal fuel oil tanks (drain connections c1). The water would be removed by fuel through the test lines.
transferring the fuel oil from saddle tanks to the internal fuel oil tanks by means of the auxiliary cooling oil pump: the pump is configured to pump the water to the the saddle tanks, the saddle tanks and internal tank is connected by means of the fuel oil transfer system. Shut the cooling water discharge to the internal tank, open the vent lines of the internal tank. The oil is forced from the saddle tanks to the internal tank by means of the pressurized water.

Draining the internal fuel oil tanks? That U-Boat ain't gonna dive?

Why would the U-Boat dive? Draining the water would be the scenario to make the internal tanks empty (i.e. to make inspection).

--
Regards
Maciek

[SnakeDoc]

Pumping fuel from the fuel/ballast saddletanks might be a problem if you use the internal fuel system as a suction system. The reason would be that the deliverypipe, now acting suction pipe, ends on top of the saddletanks to prevent watercontamination. Without a compensating waterpressure the aux fuelpump suctionpipe would end up in the air.  If for some reason you would have to transfer fuel from the saddletanks in fuelconfiguration by the aux.fueltransferpump you would use a hoseconnection possibly via the man hole.

Right. While pumping the fuel from the saddle tanks by means of the fuel oil transfer system (Treibolforderleitung), Germans simultaneously admitted the pressurized water by means of the compensating system.

--
Regards
Maciek

[Don Prince]

Hello Mr. Tore and Maciek,


The fuel transfer that I want to document would be from internal fuel storage tank like 1 IB. The reason for my interest is that when schnorchelling the cooling water pressure head to/from the internal fuel tanks is too high for the gravity tanks (14 mwc). So a directive was issued that when schnorchelling only the saddle tanks may be used as a fuel source to the gravity tank.


During the late war period, U-Boats with schnorchels were pretty much below the surface bound. Therefore, a fuel oil saddle tank low situation may exist, and then a the need to transfer fuel oil to the saddle tanks.


On Plan 9, internal tank 1 IB has a hose connection "b3" where the source is the internal storage tank 1 IB. If there was a hose connection between "b3" and "c" at the Auxiliary lubricating oil pump head, then could the pump transfer fuel through the tank selection valve chest and then to the saddle tanks? The cooling water pressure head already exists for the internal storage tank, and it's always available to the saddle tanks.  It looks to me like this would be sort of a refueling situation for the saddle tanks, and the cooling water in the saddle tanks would be forced to exit at the header tank overflow...


Does this drawing look OK?


Regards,
Don_

[tore]

Don.
I am not familiar with the German schnorchelling instructions and give my comments based on my experience. In general the internal fueloil tanks are designed for watercompensating which have many advantages. The high compensating water pressure while schnorcheling is of course a problem as the testpressure for the internal fueltanks is 8 mwc. However I don`t see the need for using the saddle ballast/fuel tanks while schnorcheling. Although your proposed system I guess would work, I don`t think it would be nessecary. What you really need is to top up the header settling/day tank in the engine room. The volume of this tank is appr. 365 liters. I would prefer to use the watercompensating system isolated from the external headertank in the wintergarten, using the handcoolingwater pump in the engine room to allow compensating water to enter any of the two internal fuel storage tanks, using the system already installed and cracking the intakevalve c1in the crossover line as per my sketch below. I estimate it would take about 1/2 hour to top up the daytank. Kindly note the external fueloil storage tanks have  reliefvalves both for overpressure and underpressure.
Tore

[SnakeDoc]

Hi Don,

The fuel transfer that I want to document would be from internal fuel storage tank like 1 IB. The reason for my interest is that when schnorchelling the cooling water pressure head to/from the internal fuel tanks is too high for the gravity tanks (14 mwc). So a directive was issued that when schnorchelling only the saddle tanks may be used as a fuel source to the gravity tank.

During the late war period, U-Boats with schnorchels were pretty much below the surface bound. Therefore, a fuel oil saddle tank low situation may exist, and then a the need to transfer fuel oil to the saddle tanks.

I can not find the source right now, but I remember that I was reading somewhere (standing order, KTB?) that when the U-Boat was fitted with Schnorchel, the over-pressure and under-pressure valves of the internal fuel oil tanks were adjusted to make them usable  during submerged cruise.

--
Regards
Maciek

[Don Prince]

Hello Mr. Tore and Maciek,


Mr. Tore - how often would you have to spend 1/2 hour hand pumping water on a Gravity Tank cycle? Also from what I remember, you did not usually have fuel oil in the saddle tanks...


Maciek - the article is at  www.uboatarchive.net/U-413INT.htm  and on page 19.


Regards,
Don_

[tore]

Don, you are right we did not use the saddletanks as fueltanks and I have tried to remember how we transferred the fuel from the inner tanks to the settlingtank in the engineroom while schnorcheling. I guess we used the normal compensatingwatersystem, which by schnorcheling is estimated to have an additional 0,6 m WC pressure to the normal surface cruisingpressure.
The internal compensatingsystem and fuelstorage tanks have as previously stated a safetyvalve at the pressurehull intake, this valve can be adjusted, but I guess we cracked the hullvalve throttling the pressure when filling the settling/daytank at a volume of half a barrel, this was done in a short time. In addition to the intake pipe reliefvalve, each internal fuel storagetank were equipped with another safety arrangement consisting of a valvechest containing an overpressure and an underpressure reliefvalve to prevent damage to the tank.
As far as I could estimate the fuel consumption of one diesel at schnorcheling would be appr. 220 litres/hour which would mean a topping up of the settlingtank a little more than twice a watch. I think Macieks indication of seeing an info on adjusting the safetyvalves migth be correct as we are talking about minor pressures.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,


I have done a major rewrite of Skizzenbuch where information has been updated and the pages are arranged to follow a logical sequence. I have backgrounds for all the plan pages of either photos or colors.


The latest version of Skizzenbuch 11 x 17 - M.pdf has been uploaded to Dropbox.


Herrn Klaus Mattes and Jak P. Mallmann Showell are working with two German Museums and several German U-Boat Interest Groups about Skizzenbuch.  They seem to be impressed with the scope and depth of our work.  I may have more info in a week or so.


Regards,
Don_


PS - Klaus Mattes wrote a book "Die Seehunde"...

[VIC20]

Great book, I have it in my little U-boat library. 

[karel]

Don Prince.  Is there any way i could buy an early access for Skizzenbuch from you?
I could really use it as a technical reference for my game. Originally i planned to wait until spring and buy from publisher, but that option is not there anymore. Having an access to Skizzenbuch would help me make a better game. I would also be happy to credit your name and book in my game if this is something that would be an interest for you.

VIC20. We spoke over email 2-3 years ago when i asked you for some technical advice. I have not forgotten my promise. If the game quality holds up from your perspective and if you wish, i can credit your name also.

Tore and Maciek
Would like to make you an exact same offer. Would be an honour to have your names also there.

[Don Prince]

Hello Karel,


Give me about a month, Klaus and Jak are working with several German U-Boat support groups and two museums promoting Skizzenbuch. I don't believe there will be any legal distribution issued because I am not asking for any monetary compensation for Skizzenbuch; my work stands on its own merit! Several years ago when I started compiling Skizzenbuch, it was intended only for my personal library; I am not the U-Boat expert like Mr. Tore and Maciek. I purchased a leather covered metal post binder for my library with gold lettering on the front cover. The binder determined the 1.75 inch spacing on the 11x17 inch binding side page layout.


My requirement: The Skizzenbuck PDF file is not protected form modification. This was done intentionally, so Mr. Tore and Maciek could modify Skizzenbuck if they so desired. However, I have only made changes to the Skizzenbuch 6 Microsoft Word files which are converted to PDF files. and then the PDF files are merged into 1 PDF file. If I give you access to my Dorpbox folder account which contains the "Skizzenmbuch 11x17 - M.pdf" file, then this file will not be distributed without my permission.


Later, I plan on purchasing "CopySafe" PDF protection software (very expensive) which encrypts the PDF file and embeds a viewer in the file. Also, it provides the PDF author with a host of other options.


Kind regards,
Don_

[Don Prince]

Hello Mr. Tore,


I believe it was mentioned that the cooling water pump in the e-room had some fittings to allow the introduction of anti-corrosion oil...  I can see a direct path through the cooling water valve chest, but it looks like the anti-corrosion oil only makes one pass through the pipes and the diesel engines. Then it goes through the cooling water system; the mufflers and to the header tank and out to sea.  Is that correct? How often was the anti-corrosion treatment done?


Regards,
Don_

[tore]

Don.
In spite of a few pipebends having severe corrosions I can not remember we used anticorresion oil. I believe the oil was pumped into the coolingwatersystem by the coolingwater handpump stb side in front of the mainengine, a spesial armed oilresistent hose was used, diameter 38mm  and length about 2 meters. Below is an image showing the system, as the plate 13 for the GW engine is not showing a correct system, I include the plate 13 a which is the  MAN system however the anticorrosion oil inlet is the same for both enginetypes. . As far as I know the anticorrosion oil came in a barrel and the end of the hose was put in the barrel.
Tore

[karel]

Don.

Thank you. I can wait a month, no problem. I am shifting some stuff around and work on sound and lighting for a while and shall return back on to systems when i have access to Skizzenbuch.
Just let me know in private message if you are ready. I am really excited for this and thank you again, this makes my life so much easier.

[Don Prince]

Hello Mr. Tore,


It looks like they could hand pumped anti-corrosion oil into the cooling water valve chest while the diesel engines were running. The hand pump's pressure head would be greater than that of the two attached diesel cooling water pump's pressure head, so the anti-corrosion oil would be mixed with the cooling water as it is pumped into the cooling water valve chest; then its piped to the lubricating oil coolers and on to the diesel engines.


Is my summery correct?


Regards,
Don_

[tore]

Don.
I guess your understanding of the anticorrosionsystem is correct. The procedure was to start the engines and let them idle, then "injecting" the anticorrosion oil by the hand pump. The oil used was an emulsifying oil having the German naval specification Zd M17. The "contaminated" coolingwater could be drained via cock f1 to the dirty luboiltank aft of the luboil systemtanks.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,


I have made some additional changes to Skizzenbuch and added an "Index." The new file is in my Dropbox account folder...


Skizzenbuch 11 x 17 - M + I.pdf


Regards,
Don_

[tore]

Don.
I have started to look through you latest Skizzenbuch and it strikes me you are gradually going into more details of the VIICs which might require an upgrading of the prevous work done. While reading page 122 dealing with the engineroom exhaustsystem I guess the exhaustblowing of the ballasttanks has been a bit neglected. The outer main exhaustvalve has a task of being a damper,  operated by the engineroomcrew to adjust the exhaustback pressure of the dieselegine in operation. I have made an image on the subject. Kindly note that the outer exhaust system including the branch  to the exhaustblowingpanel is turned 90 degrees in relation to the inner system.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you for taking the time and looking at the latest version.  I will be glad to make any changes that you deem necessary or should be changed. I know I have made many changes throughout the book form the discussions I had with you and Maciek. It always good to have a 2nd opinion by an expert! Also, I have made changes to the electronic documentation that Maciek provided (and we worked on) to get a more precise English wording. I sure hope that I have not made the info wrong or misleading.


Regards,
Don_

[Don Prince]

Hello Mr. Tore,


The outer exhaust grinding system and muffled run horizontal above the pressure hull (I believe that is correct).  Does the 90 degree rotation mean this is related to the inner exhaust grinding system.  If I rotate the inner exhaust grinding system 90 degrees counter clockwise, then the exhaust pipe coming from the diesel engine would connect to the inner exhaust grinding system at the back side near the pressure hull? (that looks logical) But I need your advise on that???


I don't want to change the middle drawing to reflect the physical 90 degree turn because we would loose the clarity of the information presented. However, I will note the physical equipment relationship for accuracy.


What do you think?


Regards,
Don_

[tore]

Don.
I made the sketch showing the inner main exhaustvalve atwartship and outside the pressurehull, the exhaust flapvalve (damper) and  silencer alongship, thus turned 90 degrees, just to make it easier to understand the working. The exhaustdamper is primarerly used while exhaustblowing the ballasttanks.
Tore

[tore]

Don.
On page 143 of your Skizzenbuch I am afraid you have misunderstood the luboil system as you have connected the gravity drain from the main engine to the suctionside of the stb.attached lubeoilpump. I guess a description of the luboilsystem would clarify the matter.
The luboil system is based on two independent systems, for each engine, being able to  interconnect if needed. It works on a dry sump principle, meaning each engine have a separate systemtank under the engine. Below is an image of the normal and alternative operations. Normal operation of the port engine is as follows: the port systemtank holds the lubeoil for the port engine and the attached lubeoil pump takes its suction (green) via a normal NR footvalve in the tank. The discharge ( red having a reliefvalve with drain (blue) to the systemtank), goes to the distribution box between the engines passing a NR valve b. Valve a1 is open and allows the oil to flow via the main oilfilter with differentialmanometers to the port oilcooler having a dirty oil pipe(blue) via cock f to the port systemtank. After the cooler the oil passes a selector cock c1, in this case normally selecting the port engine. After that cock is a small pressureline to the servomotor for the governor on the camshaftdrive side (aft) of the engine. The servomotor shuts down the engine in case of lubeoilpressure failure and assists the governor in moving the fuelrack. The discharge pipe continues on the front of the engine to a pressure reductionvalve,( rembember the small red wheel?) reducing the pressure from 3kg/cm2 to 1,5 kg/cm2 before it branches off to the main bearings, camshaft drive and supercharger. When the lubeoil has passed the enginecomponents, gravity takes the oil through drainpipes (blue) to a selectionbox to port or stb systemtanks, where port in this case, normally is selected. The attached lubeoilpumps can not take suction via the drain system.
In case of an attached luboil pumpfailure, the quickest and easiest way of an alternative would be to use the aux. electric driven lubeoilpump. The system on my image is self explaning, I guess, and as a last alternative you are able to use the stb. attached lubeoil pump, which system you`ll find on my image as well.
Tore

[Don Prince]

Hello Mr. Tore,


I have a lot of work to do... I have a question about the Pneumatic Motors that drive the valve grinding for the external exhaust valves... Are the pneumatic motors started automatically when the hand wheel is turned to close the exhaust valve, or was some other action required to start the pneumatic motors?


Also, I don't believe I see any reference to the pneumatic motors on the mechanical or electrical German shizzenbuck PLATTs either?


Regards,
Don_

[tore]

Don.
The pneumatic grinding motors for the outer exhaust dampers were connected to the LP system as German plan 12 shows on my image below. There is no automatic starting, just  opening of the small LP air valves as shown. As prevously told, when diving, the dampers had to be fully shut and you experienced always some carbon deposits on the seatings. Our procedure was to start the grinding at some 3-4 meters to obtain sea backpressure on the valve disc for better grindingeffect. As the air used was released into the engine room, you had to limit the grinding as much as possible to prevent excessive overpressure in the submarine, buggering up the reading of the gauges.
Tore

[Don Prince]

Hello Mr. Tore,


The cooling water pump in in the aft e-room...  Was there a hardware setup that would permit anti-corrosion oil to be admitted into the seawater to the cooling blowers, e-motor bearings, thrust bearings, etc.?


By the way...  What does the abbreviation "NR" stand for in your write-up about the lubrication oil system?  "Normal" - something, I guess?


Why is there a return line through cock f to the collection tank? Would something be wrong with the oil cooler when using this line?


What is the big box the the left in the schematic? Is that the pump that is driven by a rocker arm that dispenses lube oil through small tubes to those hard to reach areas?


What is the function of valve g? and what is the return line directly ti the left of the pump for?


Regards,
Don_

[tore]

Don.
I don`t think there is an anticorrosion oil "infusion" in the E-room coolingwatersystem, however it is an anticorrosion connection at the stb engine groupexhaustvalve cooling system as indicated on the image below. The yellow line indicate the system entering the Junker compressor cooling water system. It is a possisbility to connect this system to the E-motors cooling systems shown by the broken yellow line as well as a more doubtful purple broken line to the e-compressor. The broken lines indicates I am not sure of these systems. Kindly note the E-room system is copied from the MAN coolingwater system as the plate 13 of the GW system is of bad quality. Both systems in the E room are the same.
NR stands for non return eg NR valve is a non return valve.
Cock f on the pipe from the lubeoilcooler is for draining the cooler, the pipe connects with the other draining pipes like safetyalve and reducing valves.
The rectangle on far left in the lubeoilsystem is the supercharger.
Tore

[tore]

Don.
I forgot your last question. Valve g and the small branch off pipe in this system is for lubeoil to the attached gearpump in those cases the pump do not work, but still is attached idling.
Tore

[tore]

Don.
The two drainlines in front of the engine is 1. the forward sumpdraining and 2. the draining of the pto lubrication of the attached equipment in the front of the engine.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you for the info... There looks to be a 2nd thermometer and an oil pressure gauge on the oil pressure line after the oil cooled. Do you know their location? Photo?


Schematic attached...

Also, I have been reading about the difference between oil reducing valves and oil safety valves.
1. The reducing valve uses a spring and hand wheel to set the output pressure to a fixed value. However if the source pressure increases, then so does the output pressure.
2. The safety valve uses a spring and hand wheel to set the limit for its out pressure. If the source source pressure increased, then the excessive oil is drained off to hold the output pressure limit.


Valve h is definitely a safety valve (h          SICHERHEITSVENTIL )


Valve d is listed as a pressure reducing valve (d          DRUCKMINDERVENTIL)
 but has a drain line which makes me believe that the Germans were actually using a safety valve as a reducing valve - most likely to eliminate back pressure in the line.


What do you think?
Regards,
Don_

[tore]

Don.
The placing of the thermometers are indicated on the image below. Normally the temperature readings were done locally, except the cylinder exhausttemperatures, whereas the pressuregauges were assembled in an instrumentpanel for both engines placed high up between the engines, on the museums U 995 almost hidden behind a fluoroscent light tube. 
A pressurereducingvalve or more correctly pressurecontrol valve, is placed in the pipesystem to control the operating pressure in the system. The pressurecontrol valve is designed to open or shut to modulate or regulate the operating pressure. A pressure relief valve or safety valve is designed to open fully at a preset value and then shuts or resets when the pressure falls below the design maximun pressure. You should never used a pressure reducingvalve as a pressure reliefvalve to protect a structural integrity of a system.
Tore

[tore]

Don.
Below is a crossection image of a oilpressure reduction valve. As you see it is an intricate design with hydraulic ballancing bores having a drain.
Tore

[Don Prince]

Hello Mr. Tore,


OH!!! Then the pressure regulating valve is a double chambered valve with a drain...  very interesting! I was only reading about a single chambered regulating valve...


The safety valve attached to the oil pump's output...  The diesel engine's rpm will increase with speed. Therefore, the oil pump's pressure will increase as well.  This makes be believe that the oil pump cannot over pressurize the lube oil system and pop the safety valve. The only way to pop the safety valve is to have a valve shut that should be open for the lobe oil flow (a screw-up) or something got blocked like a filter or cooler.  Then the safety valve would pop and dump the oil back into its collection tank...


Am I making any sense?


Regards,
Don_

[tore]

Don.
You impression of the Germans used the pressure reducing valve d as a safetyvalve is probably based on a misunderstanding reading the pipescheme. As the drawn drainpipe from the valve looks rather big it is actually a very small drainpipe which by no means would be able to drain the system. It merely takes the small leakages from the ballancing bore in the reducing valve as can be seen on my image below.
Tore

[Don Prince]

Hello Mr. Tore,


lets assume there is a plugged oil filter... If you are cranking the engine on air, then is there is no lube oil going to the engine. Would there be anything that notified the mechanic of this problem before the safety valve pops?  Would they ever get to the point of injecting fuel?


Regards,
Don_

[tore]

Don.
Humans can always overule the interlocks. You are able to crank the engine by air without luboilpressure as well as starting the engine without coolingwater etc. The fuel rack can be moved irrespective of the governor servo.  The system is based on qualified engineers operation and it is a limit as to how many interlocks you want to install and how much complications you  would introduce.
Tore

[Don Prince]

Hello Mr. Tore,


For the GW diesel engine - would it be fair to say the safety valve works as follows:
1. The safety valve provides for high pressure relief seen at the lube oil pump head.
2. If the oil filter was getting plugged then the oil pump would see an increase in back pressure.
3. At some point the safety valve would reach the 'Cracking Point" where there would be a small flow of lube oil to the collection tank. The cracking point is generally far below the popping point.
4. If the oil filter problem continues to get worse, then at some point the safety valve will do a full vent flow or "Pop."
5. The pipe for the safety valve is not huge, but it should be large enough to create a pressure drop.
6. The safety valve is designed so that it will not recover from a full vent flow (Pop) until the pressure went down below the cracking point.
7. The lube oil pipe to the servomotor and the governor should sense the pressure drop and react by shutting down  the diesel engine.


The MAN diesel engine uses the safety valve to short the lube oil pump output to the lube oil input. I believe they are achieving the same result (a pressure drop). I have the schematics for the type IX U-Boat and the MAN 9 cylinder diesel engine and it does not have a reducing valve 1.5 < 3.0 atu in the lube oil system schematic.


I have done a lot of research on the safety valve...
 
If I assume the the GW 6 cylinder engine is at mid range rpm, then the attached lube oil pump pressure head is about 3 atu... Is that correct?


The reducing valve at 1.5 < 3 atu will create some back pressure when reducing its pressure output without an adequately sized vent line, but I guess the system can handle that back pressure with pipe lengths and passing through various components.


What do you think?


Kind regards,
Don_

[tore]

Don.
The attached lubeoilpump is of a gearwheel type meaning a positive displacement pump,  delivering a fixed volume pr. revolution. All such pumps for non compressible liquids require a safety valve to relieve the full max. volume to prevent damage in the event of fi. a shut discharge valve. As the pump is a positive displacement pump the safety valve has to open proportionally with the pressure. Generally such a safetyvalve is an integral part of the pump.
The servomotor of the governor forces the fuelrack to stop in the event of a pressuredrop below a preset minimum luboilpressure, irrespective of the cause.
Allthough they are drawn slightly diffent, there is in principle no difference between the GW and MAN systems. Below are the two systems, both system have an attached gearpump having a discharge pressure of 3 kg/cm2 and a reduction valve prior to the engine inlet to 1,5 kg/cm2. A branch off to the governor servo on the MAN engine is marked trieboelv.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you for all your patients...  I have always tended to ask questions to gain a better understanding as to how things work (a personal flaw I guess)?


In order to access and change valve settings in the lube oil distribution valve chest, it looks like a center section of the floor panel must be raised. Was this section of the floor panel hinged for ease of access? Perhaps that shinny steel screwed down floor plate on U-995 is not original?

Also, when you are injecting anti-corrosion oil into the cooling water valve chest, I believe you would select each engine side separately.  Is that correct?

Regards,
Don_

[tore]

Don.
Don`t worry, I guess asking questions is an instrument for learning. The floorplatings were raised in the way of the lubeoil valvechest between the engines as you can see on my image below. The floorplatings have been changed on the museum U 995 as you can see and they differ from the original as shown on the top photo. I don`t think the platings were hinged.
You could flush the anticorrosion oil in many ways including each engine separately.
Tore

[Don Prince]

Hello Mr. Tore,


I noticed something on your upper photo just posted...  Those pipes had the 3 band markings like the color bands on Plan 3. That would make it much easier to troubleshoot problems.  It looks like when U-995 was refurbished for the museum that the pipe color bands got painted over!


Regards,
Don_

[NZSnowman]

Hello Mr. Tore,


I noticed something on your upper photo just posted...  Those pipes had the 3 band markings like the color bands on Plan 3. That would make it much easier to troubleshoot problems.  It looks like when U-995 was refurbished for the museum that the pipe color bands got painted over!


Regards,
Don_

You are correct, most of the Colour Bands have be  painted over! There a few colours bands left in the Control Room also. It has taken me quite a while to figure out the correct colour band.

[tore]

Don and Simon.
I guess the museum U 995 being short of funds are depending upon a lot of voluntary maintenance work, unfortunately a lot of painting is done without proper guidance. This result in overpainting items which sould not be painted at all. I guess the worst case is in the engine room which got red spot all over, blue valve pushrods which never was painted and the moving fuelrack including the HP fuelump rods which are ever moving items and  rather should have lubrication than a thick layor of glossy green paint.
Tore

[Don Prince]

Hello Mr. Tore and Simon,


The US Navy deck personnel (Swabbies) had an old saying "If it doesn't move, then paint it!" I guess the diesel engine wasn't running at the time... So, we now see what happened!!! Ha ha..


Regards,
Don_

[Don Prince]

Hello Mr. Tore,


FYI... I did find a partial image of the Q Tank muffler.


Regards,
Don_

[tore]

Don.
Very good I guess we now have an image from two angles.
Tore

[Don Prince]

Hello Mr. Tore,


If a U-Boat makes a very deep dive and the pressure hull will then be compressed. Then, when the U-Boat resurfaces will the pressure hull stay compressed because there is no internal pressure to expand the pressure hull back to its original size?


If the pressure hull steel flexes inward between the round pressure frames, then I could visualize a return to the original displacement. However, as I look at U-995 there are some dimples here and there...


Regards,
Don_

[tore]

Don.
Normally the steel tensile strength of the pressurehull expands back to its original shape, however if the steel is subject to stresses exceeding the tensile strength you arrive into to the steel yield point and the steel begins to flow which means it would not retract to the original shape. The dents you see on the museum U 995 are primarily dents in the weaker part of the saddle tanks which migth derive from mooring collision. On some surface vessels hullplatings you migth see dents between the frames which might derive from weatherbeating or weldingstresses. If you see the pressurehull of a submarine you normally would`t  see such dents. A lot of modellers love to imply such dents, known as canning, I guess this is overdone particulary on the pressurehull.
Tore