Author Topic: Tores mailbox VIIC and VIIC/41 operation and technical details (Read 655355 times)

tore · « **Reply #4200 on:** 12 Dec , 2019, 06:53 »

Don I just had a look at U-Historias image of the GW mainengine front nearly a same image as below. U- historias image marks my assumed exhaustvalve lubrication point as no 14 saying this is " tubo de engrase valvula" I am not very conversant with the spanish language but I assume U Historia is of the same opinion as me. May be we can draw a conclusion.
Tore

Don Prince · « **Reply #4201 on:** 12 Dec , 2019, 14:55 »

Hello Mr. Tore,

I translated the u-history.com comment to "grease tube valve"... "Google Translate" looks to do a good job translating many languages and the source/destination language has many different combinations.

It looks like the GW Piston has no internal lube oil cooling ability. However, the GW piston has 7 compression rings and 2 lower oil control rings. Where the American GM piston design only has 4 compression rings and 2 lower oil control rings. Interesting....?

Regards,
Don_

Don Prince · « **Reply #4202 on:** 12 Dec , 2019, 23:05 »

Hello Mr Tore,

I FOUND IT!!! U-Boat Archive Series Volume 7, Report on U-570 - H.M.S. Graph - Page 70

Main Engine Liner

"Cylinder lubrication is by means of a Grutzner pump with tow connections to each liner, inboard and outboard. There are no oil groves cut in the liner walls and no holes are provided for piston slinging gear."

Main Engine Pistons

"They are fitted with 6 impulse rings, 1 upper scraper ring and 2 slotted scraper rings, Drain holes are drilled behind the 2 lower scraper rings and also in the oil catchment groves. The groves, 2 in number are situated immediately below each slotted scraper ring."

Don - Therefore, it looks like pump connection is situated so that the nozzle will always be in between the 7 top piston rings (compression rings) and the 2 lower scraper rings (oil control rings).

Exhaust and Induction Valves - Page 72

"The stems of both exhaust and induction valves are lubricated by a mechanical pump driven from a camshaft'"

Connecting Rods - Page 71

"The connecting rod has a large diameter bore through it, being reduced near the eye of the rod. The lubricating oil is taken round the gudgeon and fed through the pin through 4 holes at 45 degrees above and below horizontal."

The only thing that I'm not sure of is how are the rocker arms lubricated, Is the above describing how the rocker arm pivot point is being lubricated...?

Regards,
Don_

tore · « **Reply #4203 on:** 13 Dec , 2019, 00:41 »

Don U-570 ex HMS Graph was a VIIC built by Blohm & Voss and the main engines were MAN m6v 40 46 type being turbocharged and a different construction than the GW engines. Although they did the same job. The MAN design was a bit more "advanced" than the GW engine but the latter was considered to be more reliable. Sorry I don`t think we can compare the details of the GW engines with the MAN.
Tore

Don Prince · « **Reply #4204 on:** 13 Dec , 2019, 00:53 »

Page 64 - two sets of GW 4-cycle engines built by Blohm & Voss under Krupp License at Hamburg...

Don_

tore · « **Reply #4205 on:** 13 Dec , 2019, 02:20 »

Don
You are absolutely right, U 570 was equipped with GW engines, I did not checked the British report but the US report of september 28th 1941, classified reliable, and made by 3 US naval officers who was onboard inspecting the submarine U570 23.- 26. september 1941 at Hvalfjordur Iceland. Obviously not very reliable as they say on page 51 section II-C- 2 :" Main engines The two 6 cylinder, 4 cycle, solid injection M.A.N engines are rated at 1400 horsepower each at 470 rpm with supercharger cut in........" I should of course had been a bit suspicious on the cut in expression. But in a hurry I just noted the MAN. So much for reliable source, sorry Don. I guess we possibly could accept the cylinder lubrication by the GRUETZER lubricator and leave the in lubrication of the fulcrums to the manual greaser I am a bit bewildered on the valvestem lubricator driven by the camshaft. For easy access to the fulcrum lubrication on the top a foldable step was arranged along the engine. as shown on my image below.
Tore

Katuna · « **Reply #4206 on:** 13 Dec , 2019, 08:12 »

Ahem...

https://models.rokket.biz/index.php?action=dlattach;topic=1621.0;attach=11906

Don Prince · « **Reply #4207 on:** 16 Dec , 2019, 22:37 »

Hello Mr. Tore,

The GW Diesel engine design had no top valve cover... Was there any maintenance procedure where the push rods and valve rocker arms which were exposed to the engine room were lubricated? Were there any grease nipples located on the GW Diesel engine?

I have attached 2 charts:
<1st chart is the GW Diesel engine crank shaft and ignition timing>
<2nd chart is the Lubricator injection and the GW Diesel engine stroke timing>

Regards,
Don_

tore · « **Reply #4208 on:** 17 Dec , 2019, 03:43 »

Don, I don`t think we had any fixed lubrication instructions for the many fulcrums and contact points on the top of the engines. As mentioned the technology was pretty much based on pre WW2 practise and local manual lubrication was the custom. I guess you are able to see the lubrication points on the tops of the valve rocker arm on the enclosed image below. There were no greasecups on this point as far as I remember an oildrop was added at regular intervalls to the engineer/greasers judgement. The manual point lubrication was an important time consuming part of the engine crews watch. To day I am afraid that many layers of fancy paintings are hiding the many lubricating points on the top.
Tore

Don Prince · « **Reply #4209 on:** 17 Dec , 2019, 14:32 »

Hello Mr. Tore,

The attached photo looks to have captured the lube point for the valve rocker arm...

Regards,
Don_

tore · « **Reply #4210 on:** 18 Dec , 2019, 01:37 »

Don. I am afraid it might be a bit more complicated than indicated on your image. I guess your yellow arrow is pointing at the setscrew (locking) for the pedestal shaft and thus fixed to the pedestal. The rockerarm is pivoting on this fixed shaft and hence need lubrication which is admitted via a wart on the rocker arm. Usually the fulcrum shaft is locked and the arms are pivoting. The shafts are usually locked in the support either by segerings or setscrews, the latter can easy be mistaken for a lubrication wart as the threaded boring is in a wart similar to the luboil bore. My image below explain what I mean.
Tore

Don Prince · « **Reply #4211 on:** 18 Dec , 2019, 17:16 »

Hello Mr. Tore,

New terminology for me... "Lubrication Wart" is this a raised circular area with a hole in the center going down to a shaft that needs lubrication? Since these are rocker arms, would you use grease rather than lube oil because of the constant up and down motion that may sling a lube oil out of the "Wart." Or, does the Wart have a cover?

Regards,
Don

tore · « **Reply #4212 on:** 19 Dec , 2019, 00:55 »

Don.
I guess warts on engineparts is not proper english for the extra materials needed for bores with or without threads primarily on cast steel /iron. Not always used for lubrication, but bores for setscrew, drainplugs etc. Grease need pressure to get to the lubricating points hence mostly luboil is used. Proper lubrication of a dieselengine having an open top was difficult before the topcover was introduced. The time consuming pointlubrication was one thing, another was the drains from all these points which you didn`t like to get in to the bilges. Hence an elaborate system of funnel and small drainpipes was installed to take the drain from the top. The system was susceptible to damage especially during maintenance.
Tore

Don Prince · « **Reply #4213 on:** 21 Dec , 2019, 14:53 »

Hello Mr. Tore,

I noticed that the Selector Valves for air distribution in the Diesel engine room were both painted red on U-995, even though they look to be on the port and starboard side. Is red the original color for both valves?

Regards,
Don_

Don Prince · « **Reply #4214 on:** 21 Dec , 2019, 16:33 »

Hello Mr. Tore and All,

Merry Christmas and Happy New Year; Wishes for a Peaceful New Year and Lasting Friendship!

Kind Regards,
Don_

tore · « **Reply #4215 on:** 22 Dec , 2019, 02:29 »

Quote from: Don Prince on 21 Dec , 2019, 14:53

Hello Mr. Tore,

I noticed that the Selector Valves for air distribution in the Diesel engine room were both painted red on U-995, even though they look to be on the port and starboard side. Is red the original color for both valves?

Regards,
Don_

Don. On the museums U 995 they have not tried to conserve the original colours and it is hard to see the system of colours ( if any). Do not use the red painted valves, cocks, grease cups, gauges etc. as a reference. They have evidently left it to the painter to chose the colour he prefers, to me it looks more like an amusement park than the interior of a WW2 VIIC.
Tore

tore · « **Reply #4216 on:** 22 Dec , 2019, 03:39 »

To all the VIIC entusiasts!
Tore

SG · « **Reply #4217 on:** 23 Dec , 2019, 11:32 »

Thank you Tore! Much appreciated. Best Christmas wishes to you too and a thousand THANKS for your incredible contribution to the Forum. Something that has become more and more Mythologic over the years.
Merry Christmas!

bianco64squalo · « **Reply #4218 on:** 23 Dec , 2019, 23:04 »

Merry Christmas to all also from me ... Santa Claus brought me the best gift you can receive: a new love .... after a long time, the smile returned to my lips, the warmth in my heart ... who knows that the desire to approach modeling will not come back to me again ...
Best wishes to all

bianco64squalo · « **Reply #4219 on:** 23 Dec , 2019, 23:05 »

Merry Christmas to all also from me ... Santa Claus brought me the best gift you can receive: a new love .... after a long time, the smile returned to my lips, the warmth in my heart ... who knows that the desire to approach modeling will not come back to me again ...
Best wishes to all !!!!

dougie47 · « **Reply #4220 on:** 24 Dec , 2019, 03:48 »

Hello all,

Merry Christmas to all. Hope you get time at the modelling table over the festive break.

Cheers,

Dougie

Katuna · « **Reply #4221 on:** 26 Dec , 2019, 08:04 »

I'm a bit late but I hope everyone had a blessed Christmas and here's to a happy and prosperous New Year.

Filippo, that is wonderful news. Love is the best gift of all.

Don Prince · « **Reply #4222 on:** 02 Jan , 2020, 01:38 »

Hello Mr. Tore,

I was reviewing some of the photos that I have collected over the years. Does this photo taken below deck look to be the Knife Oil Filter (page 153) that was added after the Oil Purifier was removed?

<see attached image>

Regards,
Don_

PS - It looks like there have been 400 downloads of Skizzenbuch from the Subcommittee.com website.

Personally - I had a heart attack Christmas Eve and spent 4 days in the hospital and they installed a stent in my right artery. Later, they may do Robotic Surgery and bypass a couple partial blockages in my left artery. My heart plumbing is beginning to look more like a U-Boat lube oil diagram!

tore · « **Reply #4223 on:** 02 Jan , 2020, 02:46 »

Don, sorry to hear about your heart issue, If your heartplumbing looks like a plate 13 coolingwatersystem don`t forget there is an anti corrosion connection to be used regulary to prevent further damage.
As to your posted image I guess you are showing a gatevalve (sluicevalve). As can be seen on my image below there are 5 gatevalves in the coolingwater crossoverpipe and I guess your image shows one of the 3 centervalves. Gatevalves are free flood valves and used in places where you want as little resistance as possible, however the valve housing needs a lot of space and might resemble a filtercasing.
Tore

tore · « **Reply #4224 on:** 02 Jan , 2020, 03:01 »

Don, Both lubeoilfilters are pretty close and before the coolers as can be seen on my (Simons ) image below.
Tore

Katuna · « **Reply #4225 on:** 02 Jan , 2020, 08:02 »

Jeez Don, hope you're doing ok. What a great Christmas gift. Glad you have a sense of humor about it. Congrats on the book too.

Don Prince · « **Reply #4226 on:** 03 Jan , 2020, 11:52 »

Hello Mr. Tore,

Reviewing Simon's piping drawing:
1. It looks like the 2 lube oil filters near the oil coolers are the strainer type filters which have always been in place.
2. The six (6) valves a, a1, and b on the valve chest look to be clustered in the center of the drawing.
3. What is the device at 8 o'clock (lower strainer) and 10 o'clock (upper strainer)?
4. The port and starboard water supply valves don't look to be air activated weed clearing?

<image attached>

Regards,
Don_

tore · « **Reply #4227 on:** 03 Jan , 2020, 13:49 »

Don, I am sorry in a hurry I posted the normal Plate 14 luboilsystem which shows the old execution with the luboil strainer. I don`t have any scheme showing the new luboilfilters in place but assume we once figured out they would be placed as indicated on Simons image. I am not 100% sure that Simons image is his final and I should have mentioned that as well. I don`t think you should use same in your Skizzenbuch. The weedblowing system is indicated on the well known plate 13 coolingwater crossover pipe intakes, but the pasting on the port side was not complete and hence omitted. In fact I guess i should not have posted the lubeoil system as my answere was on the image of the gatevalves in the crossover sea coolingwater pipe.
Sorry by the confusion I created, you cannot use the plate 13 to show the later version of the systems. Evidently sometimes things goes to fast for a 91 year old man.
Tore

tore · « **Reply #4228 on:** 03 Jan , 2020, 14:11 »

Don. Sorry I missed your question on some items indicated on the luboil strainers, I am not sure I got your question right, but I guess you are referring to the manometer showing the pressuredrop over the strainer.
Tore

Don Prince · « **Reply #4229 on:** 03 Jan , 2020, 18:53 »

Hello Mr. Tore,

You are a very sharp dude at 91... I have attached Simon's drawing and I have labeled as to what I believe are the Strainer Filters and the Knife Filters. The schematic does not include the Knife Filters as expected, but it looks like Simon's drawing does so...

Don't play that "Old Dude Card" on me! You out lived Maciek, and you could possibly out live me as well and be the last man standing!

Regards,
Don_

Katuna · « **Reply #4230 on:** 07 Jan , 2020, 08:17 »

I have a question regarding the Aux cooling Water Pump location. I cannot seem to find any photos of the forward Stbd bulkhead area and I'm trying to figure out exactly where the pump is located. Is it completely under the deck plates? Looking at Simon's drawings it appears to be a vertical pump, slightly smaller than the Aux LO Pump.

I can't determine the elevation of the pump. I need to scratchbuild one which isn't that difficult. I just need to know where the heck it goes.

tore · « **Reply #4231 on:** 07 Jan , 2020, 13:53 »

Katuna.
no wonder, I don`t have a photo of the pump but I guess you are able to see a small part of it under the writing plate, quite near the valve-chest on stb. side. I guess the pump has a bulkhead bracket to be fixed to the fore bulkhead, just beneath the floorplate. On my image you see the double sea inlet valve for the crossover pipe, might be an indication of the location. It is indeed a very narrow area and sharp pipebends.

Tore

Don Prince · « **Reply #4232 on:** 07 Jan , 2020, 14:22 »

A little better view....
Don_

Katuna · « **Reply #4233 on:** 07 Jan , 2020, 15:39 »

Thank you both so very much! I have anguished over that pump for ages. Well, maybe anguished is a little overly dramatic but nonetheless, it has puzzled me for some time. Thanks again gentlemen.

tore · « **Reply #4234 on:** 09 Jan , 2020, 02:39 »

Katuna I have taken one of Simons images of the coolingwater system, I am not sure he consider same final but superimposed my idea of the bulkhead mounted aux. coolingwaterpump
Tore

tore · « **Reply #4235 on:** 09 Jan , 2020, 03:21 »

About 10 years after the Norwegians decided to hand over KNM Kaura ex. U 995 they started the restauration of the tower from the Norwegian design to the orginal German design. Here is an image of the start of the tower restauration prior to the hand over ceremony november 1971.
Tore

Katuna · « **Reply #4236 on:** 09 Jan , 2020, 07:50 »

Tore - Thank you very much. That plate drawing is much easier to see too.

What were the main changes the Norwegian Navy made to the tower when they took possession after the war?

tore · « **Reply #4237 on:** 09 Jan , 2020, 08:24 »

Katuna.
As we didn`t need the heavy AA guns we dismantled the wintergarten as can be seen on my image below.
Tore

tore · « **Reply #4238 on:** 09 Jan , 2020, 08:38 »

Katuna.
A more modern version of the tower was the sail as shown on the image of knm Kya ex. U 926 below.
Tore

Don Prince · « **Reply #4239 on:** 09 Jan , 2020, 20:36 »

Hello Mr. Tore,

The photo of the modernized Kya reveals a clear wind screen at the front of the bridge/tower sail. Was it a fold down type or permanently in place. There also looks to be an extension tube to the aerial periscope. Did they switch from using the attack periscope while schnorchelling to the aerial periscope because of the larger head optics?

This would mean that they extender the length of the aerial periscope to place it near the schnorchel head... That would eliminate the issue with the exhaust gases in front of the attach periscope causing vision problems.

<See attached drawing>

Regards,
Don_

tore · « **Reply #4240 on:** 10 Jan , 2020, 01:02 »

Don.
The modernizing of our VIICs was an element of research in our plans for renewing/upgrading our submarine fleet. Although I was the chief engineer of KNM Kya ex. U 926 in 1954 I was not involved in this work, but knew the designer very well. I am sorry I don`t know the details. It was only modernized one of our VIICs, KNM Kya, as shown on the image. The conclusion of the research was it is better ( and less expensive) to build new submarines rather than converting the old VIICs hence we contracted 15 new submarines ( a new class) in Germany. Time had passed and changed, the situation was different and WW2 was remote and the VIICs were due for the museum.
Tore

Don Prince · « **Reply #4241 on:** 11 Jan , 2020, 01:37 »

Hello Mr. Tore,

U-926 became KNM Kya (S307) and served until 1962, and the submarine was scrapped in 1964. Using the reshaped bridge style of the Walther U-Boats, instead of the usual VII C bridge (Minus the wintergarden, the AA platform behind the bridge and the armaments), only an insignificant increase in speed resulted, but depth keeping properties were greatly improved. The final Kya bridge/tower conversion was very modest <attached photo> compared to the original proposed Walther bridge style renovation. The bridge sail had a notch on the port side where the un-modified schnorchel raised from the unchanged bed in the wooden deck structure.

Don's Note - Because of the increased height to the aerial periscope tube casing, it looks like they extended the length of the aerial periscope to just above the schnorchel mast head for better observation while scheorchelling. This accomplished two benefits: the aerial periscope had a larger optics head and tilted for better observation, and the placement of the attack periscope inback of the diesel exhaust vent created a vision problem at times.

It looks like the Norwegians put a lot of thought into the U-Boat Type VII C renovation project, and we have Mr. Tore to thank for preserving these photos from the past.

Regards,
Don_

Don Prince · « **Reply #4242 on:** 13 Jan , 2020, 18:25 »

Hello Mr. Tore and All,

Here are the attached photos of the only known printed version of Skizzenbuch. The metal covered leather post binder and the 11 x 17 inch 80 pound card stock paper and the printing cost came to about $690.00. This was my Christmas present to me!

Regards,
Don_

Don Prince · « **Reply #4243 on:** 13 Jan , 2020, 18:27 »

More images...

tore · « **Reply #4244 on:** 14 Jan , 2020, 00:50 »

Don.

Fantastic, some xmas present, but you deserve it, having the stamina to fulfil the collection of informations which makes the complete Skizzenbuch. It is of course an expensive task to print one of the kind book, but it must be a collectors item. Mission accomplished, congratulation!!
Tore

Katuna · « **Reply #4245 on:** 14 Jan , 2020, 07:35 »

Wow Don, what a fantastic book. I wish it were financially viable to put it into print. At $700 a pop, it's just a bit out of my price range (at least if I still want to sleep inside my house!) but a soft back coffee table version would be wonderful. Too bad it's such a limited market. If you could get a version down to $100 I bet you could sell a few at Laboe.

Congratulations on such a beautiful end to a long project.

Don Prince · « **Reply #4246 on:** 14 Jan , 2020, 20:05 »

Hello Mr. Tore and All,

Thank you all for your approval of my printed Skizzenbuch. However, I just added one page to the front of the book just after the paisley cover page. It is an autographed photo of Oberleutnant zur See Hans-Georg Hess who was the last German Commander of U-995 during WWII.

Regards,
Don_

SG · « **Reply #4247 on:** 15 Jan , 2020, 11:04 »

Congratulation Don! It 's been a titanic effort but what a reward! Thank you for that. i hope to be able to buy a copy someday. Enjoy the taste of victory now

Don Prince · « **Reply #4248 on:** 23 Jan , 2020, 19:11 »

Hello Mr. Tore and All,

I provided the www.Wehrmacht-Awards.com/Kreigsmarine War and Qualification Badges/ website with a download of Skizzenbuch and it looks like there will be more than 240 downloads within a week and their members are worldwide... I have been a member for several years and there experts helped me to determine if some of my badges and Iron Crosses were original or reproductions...

Regards,
Don_

Raymic1 · « **Reply #4249 on:** 24 Jan , 2020, 14:11 »

Congratulations Don.
Fyi.
I also promoted the download on multiple Facebook U-boat sites.
From the comments a lot of members downloaded and enjoyed it. Thanks

NZSnowman · « **Reply #4250 on:** 02 Feb , 2020, 15:24 »

Quote from: Don Prince on 13 Jan , 2020, 18:25

Hello Mr. Tore and All,

Here are the attached photos of the only known printed version of Skizzenbuch. The metal covered leather post binder and the 11 x 17 inch 80 pound card stock paper and the printing cost came to about $690.00. This was my Christmas present to me!

Regards,
Don_

Hi Don, The metal covered leather post binder look beautiful! Would be keen to do something like that for my book, where did you get it done?

NZSnowman · « **Reply #4251 on:** 02 Feb , 2020, 15:27 »

Quote from: Don Prince on 09 Jan , 2020, 20:36

Hello Mr. Tore,

The photo of the modernized Kya reveals a clear wind screen at the front of the bridge/tower sail. Was it a fold down type or permanently in place. There also looks to be an extension tube to the aerial periscope. Did they switch from using the attack periscope while schnorchelling to the aerial periscope because of the larger head optics?

This would mean that they extender the length of the aerial periscope to place it near the schnorchel head... That would eliminate the issue with the exhaust gases in front of the attach periscope causing vision problems.

<See attached drawing>

Regards,
Don_

Not sure if this is helpful but the aerial periscope on U-995 is not for a Type VIIC its from a Type XXIII.

Don Prince · « **Reply #4252 on:** 02 Feb , 2020, 19:24 »

Hi Simon,

The post binder came from:

http://www.spectra-associates.com/postbinders/postbinders.html

They will do embossed printing on the binder as well... The binder has a small hole in the binding end where you insert a key. You turn the key several turns which moves a locking slide to open the binder. They have end covers to match the binder and the post comes at a standard length and you add extensions to increase the binder width. Also, I believe the posts come in 2 diameters 5/16 and 3/8 of an inch. Here is my order# 34154-F to see my complete order...

I thought the aerial periscope top half was just another Type VII C attack periscope?

<see attached photos>

Do you have additional info?

Regards,
Don_

tore · « **Reply #4253 on:** 03 Feb , 2020, 06:38 »

Don and Simon. It seems to me that they have removed the aerial or navigation periscope on the museum U-995 and possibly substituted with an attack periscope for some reason. Below are a few images showing the original aerial, navigation periscope from my time onboard. The other image shows the last German CO Hess during a visit end 1990 looking into the aerial , navigation periscope, currently installed and clearly a different type. The last image shows U-995 returning from her last patrol in the Barentz sea march 1945 to Trondheim to have her Schnorchel installed.
Tore

NZSnowman · « **Reply #4254 on:** 03 Feb , 2020, 17:10 »

Quote from: tore on 03 Feb , 2020, 06:38

Don and Simon. It seems to me that they have removed the aerial or navigation periscope on the museum U-995 and possibly substituted with an attack periscope for some reason. Below are a few images showing the original aerial, navigation periscope from my time onboard. The other image shows the last German CO Hess during a visit end 1990 looking into the aerial , navigation periscope, currently installed and clearly a different type. The last image shows U-995 returning from her last patrol in the Barentz sea march 1945 to Trondheim to have her Schnorchel installed.
Tore

Yes, in the first photo you can cleanly see the Type VII navigation periscope and they changed it to a Type XXIII attach periscope. Maybe the old periscope was damage $:-\$

Don Prince · « **Reply #4255 on:** 03 Feb , 2020, 22:01 »

Hi Simon,

Do you have any documentation or photos that will verify it is a Type XXIII periscope? It looks like the forward periscope optical tube has a much smaller diameter than the original Type VII C Aerial Periscope optical tube...

Regards,
Don_

Don Prince · « **Reply #4256 on:** 03 Feb , 2020, 23:27 »

Hello Mr. Tore and Simon,

It looks like Simon is correct about U-995 aerial periscope being replaced with a Type XXIII attack periscope...

1st image from <U-995>

2nd and 3rd image - U-2367 (S171 U-Hecht) Captain-Lieutenant Bringevat stands at the periscope on the submarine Hecht. On the submarines of the XXIII series a periscope of 7.5 m in length was installed, its stroke was 4.16 m. It could be used for day and night attacks. Small changes in depth made the commander often change his posture (to engage in "periscope squatting").

Regards,
Don_

tore · « **Reply #4257 on:** 04 Feb , 2020, 03:54 »

Don and Simon.
Below an image showing the difficult position of an aerial/navigation periscope squatting, the other showing the comfortable sitting and turning the attack periscope by footpedals.
I am not sure, but we had one type XXIII submarine in our fleet KNM Knerten, ex U-4706 having an unfortunate career of battery explosion and was never commissioned. It could be the periscope was donated to the germans at the time of handing over the U 995.
Tore

NZSnowman · « **Reply #4258 on:** 04 Feb , 2020, 13:31 »

Quote from: Don Prince on 03 Feb , 2020, 22:01

Hi Simon,

Do you have any documentation or photos that will verify it is a Type XXIII periscope? It looks like the forward periscope optical tube has a much smaller diameter than the original Type VII C Aerial Periscope optical tube...

Regards,
Don_

When Maciek and I were working on the periscope project we realise it was the wrong periscope.

Don Prince · « **Reply #4259 on:** 05 Feb , 2020, 00:01 »

Hello Mr. Tore and Simon,

Do we have any idea as to what happened to the original U-995 aerial periscope?

Regards,
Don_

Raymic1 · « **Reply #4260 on:** 05 Feb , 2020, 17:04 »

Fyi
You could also ask that question as well on the curators Facebook site if no one is sure.

Freundeskreis U995

http://Https://m.facebook.com/pages/category/Monument/Freundeskreis-U995

Fyi. I cant seem to get this link to work but just search Freundeskreis U995 on FB.

NZSnowman · « **Reply #4261 on:** 05 Feb , 2020, 22:24 »

Quote from: Don Prince on 05 Feb , 2020, 00:01

Hello Mr. Tore and Simon,

Do we have any idea as to what happened to the original U-995 aerial periscope?

Regards,
Don_

I will check my old email from Maciek and see if I can found anything.

tore · « **Reply #4262 on:** 06 Feb , 2020, 00:26 »

Don I don`t know but they did a lot on the KNM Kaura ex. U-995 after my time. If the original existing aerial/ navigation periscope was ok it could of course be a spare one for the other VIICs in operation. Such equipment wasn`t easy to get just after the war. In the end of 1950 we were looking for solution of renewing our submarine fleet and as an alternative we looked at modernizing the VIICs which turned out to be very complicated and expensive to that of building new ones from scratch, thus I guess the original periscope possibly was used as spare for KNM Kinn and KNM Kya. KNM Kaura at that time was operated as a training submarine.
Tore

Don Prince · « **Reply #4263 on:** 12 Mar , 2020, 16:25 »

Hello Mr. Tore, Simon, and Mark,

To date it looks like there have been well over 1,400 downloads (Subcommittee.com,WehrmachtAwards.com, and numbers unknown from the AMP website) of Skizzenbuch; I am very grateful for all of your assistance in the project. Also there looks to be websites in the UK, China and Russia who are distributing Skizzenbuch with a slow 5 1/2 hour download speed, or a 4 minute download speed for $7.95 to $89.95 (They also distribute many other Copyrighted books; most likely ***Pirated***).

I have been working on an Addendum Booklet for Skizzenbuck to post corrections, and I have had input from one reader where I corrected 2 Type-o's in Skizzenbuch on page 479 in a drawing which could not be checked in Word. These type-o's will be in the CD that I sent to you all (Sorry about that)! If you all have any suggestions for the Addendum Booklet, or corrections for Skizzenbuch, then please let me know...

My time has become more available and relaxed (I still have an upcoming stress test after my heart attack and possible Robotic Bypass). I have restarted working on "Skizzenbuch: U-Boat Type IX C Project" and have a rough draft of about the first 100 pages... Any input would be highly appreciated, and I plan on posting conversations on this forum...

Regards,
Don_

Don Prince · « **Reply #4264 on:** 13 Mar , 2020, 05:57 »

Hello Mr. Tore,

Additional research...

The Norwegian Navy got U-4706 Knerten a Type XXIII U-Boat in October 1948, and in April 1950 transferred/used by the Royal Norwegian Yacht Club for storage. She was stricken in 1954 and broken up. This is possibly where the Type XXIII Attack Periscope came from that was installed into U-995 Kaura. So possibly, U-995's Aerial Periscope was damaged while used for training and it got replaced with what was available at that time.

What do you think?

Regards,
Don_

Don Prince · « **Reply #4265 on:** 18 Mar , 2020, 17:05 »

Hello Mr. Tore,

Are all the images in this photo of U-995?

Regards,
Don_

tore · « **Reply #4266 on:** 19 Mar , 2020, 01:44 »

Don.
The two upper (bad) photos are originals of KNM Kaura ex U995 taken by me during annual drydocking in 1953. The lower photo is details of assumed zinkanodes on my model of KNM Kaura.
Tore

Don Prince · « **Reply #4267 on:** 27 Mar , 2020, 03:21 »

Hello Mr. Tore and Simon,

I was wondering why we have not seen zinc anode plates attached to the protective structures ahead of the bow hydroplanes. I've seen images where the forward protective structure has eroded away/gone from the aft tip (bow) extension where the hydroplane actually pivoted in the structure.

"Iron is also the most corrosion-prone material when it comes in contact with air and water. A ship is continuously in contact with water and moisture-laden winds which makes it highly susceptible to corrosion. The outer body of the ship (mainly hull) is continuously in contact with water, making it extremely vulnerable to corrosion. It is for this reason sacrificial anodes are used to protect the parent material."

The above article talks about winds and the anodes are in the aft section with a huge propeller. Does the prop create the moisture winds which induce the corrosion - electrolyses process and thus requiring the zinc anode plates?

It looks like the zinc anode plates were only used to protect the aft hydroplanes, rudders, and the support structures. Also, none on the hull or the bridge, and I have seen quite a few photos of the bridges just rusting away... Were the U-Boats not believed to survive the war long enough for rust/corrosion to be a problem?

Regards,
Don_

tore · « **Reply #4268 on:** 27 Mar , 2020, 08:59 »

Don.
The stern of a VIIC has a great numbers of materials with different potentials which might cause heavy corrosions if not protected. The idea of zink anodes is that you protect all these different materials by introducing a sacrifice anode protecting all these different alloys, hence Zink is used for anodes. The anodes are placed for an optimal protection for the various materials, at hydroplanes, rudders, A-brackets and propellers. In order to have an optimal contact, the zink should be fixed to the item to be protected by ensuring the best possible metallicsurface contact hence bolted, or tack welded to a steel strap casted in the zinkanode, no paintings on the surfaces. In addition to galvanic corrosion the area suffered cavitation corrosion primarily pittings on the propeller blade roots, caused by bad propeller flow. The bad flow created small vacuum bubbles rapidly filled with steam. The eventual implosion of the vapour bubbles caused noise and the implosions extracted small cavities in the propeller material. Galvanic corrosion can create substantial damage at strange places, hence placing of the protecting anodes might vary substantially and same are sometimes placed according to experience. F.i. when a standard propeller of special metal alloy is changed by a cast steel propeller, the placing of the zink anodes would possibly have to be changed, hence you would have a number of anode locations on various VIICs.

Finally if you have a closer look at the old U 995 you shall see deep corrosions in the pressurehull. Some modelbuilders have taken great effort in copying same. These are galvanic corrosions due to negligent of maintenance and possibly hostile environment (pollution) for years. With such a pressurehull the U-995 would not be fit for a frontline submarine during the war.

In my time we used Zinc chromate a yellow painting as a anti corrosion painting and not zinc anodes in the ballasttanks etc.
Tore

Don Prince · « **Reply #4269 on:** 28 Mar , 2020, 18:59 »

Hello Mr. Tore,

Has the COVID-19 Virus shutdown Norway like the rest of the world? Maureen and I, just went grocery shopping and most food items have been restocked, but paper towels, toilet paper, and sanitation products are not available as of yet. How about your location...

Regards,
Don_

tore · « **Reply #4270 on:** 28 Mar , 2020, 23:14 »

Don. We are indeed shut down, As my oldest son was traveling in Kenya we were kept busy getting him home, he is now in quarantine for a couple of weeks, we are in quarantine, voluntary in our home, as we are classified as belonging to a risky group, mainly because of age. In all, this country was reasonably well prepared so we have currently a low deathrate, only 20 in a population of 7 million. I never understood the great demand for toilet paper during crises like this. We order all our groceries by phone and get it outside our door, we dont`t even see the delivery guy. Good old U 995 KNM Kaura would be the place to be right now.
Tore

Don Prince · « **Reply #4271 on:** 31 Mar , 2020, 13:42 »

Hello Mr. Tore,

I have attached four (4) photos of the Bow Ice Shield which is used to protect the torpedo tubes in Winter Arctic waters when iced over. It looks like they could release the three (3) front cables and use the last cable to retain the shield. It looks like the last cable uses the bow cleats near the deck edge and the bollards to hold the cables and retain the shield. However, this is just a guess on my part and I can not seem to find and description/data just these photos on the internet...

Regards,
Don_

tore · « **Reply #4272 on:** 01 Apr , 2020, 00:55 »

Don, Simon, Dougie47 and others.
In my time we operated from the German built submarine pens in Trondheim. The pens were primarily built for submarine operation towards the convoys heading for Murmansk. We mainly used one of the 2 pens and the access to the pen was normally covered with ice during the winters. I never saw anything like the bow ice protection shown on your images, neither in the stores, nor in the workshops. We had continuously a small tug/icebreaker keeping the access open. I can not imagine they used this cumbersome rattling devises on their frontline submarines, I should imagine this was, as previously said, probably used for training boats operating out of northern German harbours. Below an image showing the normal winter condition in Trondheim, I guess you are able to see the small harbour tug/icebreaker as well as KNM Kaura ex U 995 entering the pen after returning fra an artic mission in winter 1953. Normally the open waters north of North cape and Murmansk were ice free except a few narrows and harbours.
Tore

tore · « **Reply #4273 on:** 01 Apr , 2020, 02:37 »

Don, Simon,Dougie47 and others.
Come to think about it. There were special missions like erecting automatic weather stations for submarines frequently in the icy waters of artic like, Canada, Greenland and Spitsbergen, IX boats were used and might have been fitted with Iceshields. The boats were to my knowledge stripped for torpedoes and might have needed som ice protection when landing the equipment.
Tore

Don Prince · « **Reply #4274 on:** 01 Apr , 2020, 15:50 »

Hello Mr. Tore and All,

Attached is a photo from the book "U-BOATS: The Illustrated History of the Raiders of the Deep" by David Miller. The photo Showa a U-Boat Type IXC equipped with an Ice Shield as what Mr. Tore described in the previous posting.

Regards,
Don_

Don Prince · « **Reply #4275 on:** 03 Apr , 2020, 03:55 »

Hello Mr. Tore and All,

Really nice artwork...

Regards,
Don_

SG · « **Reply #4276 on:** 07 Apr , 2020, 07:45 »

Don I found another pic of the icebreaker, a frontal closeup. Boat is U 48. hope this helps

http://cubeupload.com/im/SGm/U48Icebrkr.jpg

Cheers,
SG

Don Prince · « **Reply #4277 on:** 07 Apr , 2020, 23:16 »

Hello SG,

Thank you, that was like one of the photos that Dougie Martindale emailed to me...

Regards,
Don_

Don Prince · « **Reply #4278 on:** 07 Apr , 2020, 23:26 »

Hello Mr. Tore and All,

I have been working with Simon on the vent valve for MBT 1. Back when I was working on FBT 2, MBT 3, and FBT 4, I discovered the U-570DTPlate28.jpg from the uboatarchive.net was drawn wrong by the Germans where the levers pulled down had the vents closed (WRONG!).

Today Simon noted that the drawing for the vent valve for MBT 1 would never function because the flap valve plate was on the outside of MBT 1. It must be on the inside of MBT 1 to be functional. This was also incorrect in the u-historia.com drawings that I got from them.

I corrected Skizzenbuch and here is the attached corrected drawing...

Regards,
Don_

Don Prince · « **Reply #4279 on:** 10 Apr , 2020, 01:15 »

Hello Mr. Tore and All,

During your service on U-995 and U-926 did you have an occasion to examine the construction of MBT 1; the rudder pedestal and the dual rudders? The question:

1. Is there a notch in the top of MBT 1 which allows the rudder pedestal's drive rods to control the dual rudders?
2. Is there a channel passing through MBT 1 which allows the pedestal's drive rods to control the dual rudders?

See the attached drawing... Do you have any images or better drawings?

Regards,
Don_

tore · « **Reply #4280 on:** 10 Apr , 2020, 10:52 »

Don.
Referring to the lower image. I guess the rudder drive goes through the pressurehull as shown between frame 3 and 4 to the yoke of the rudders situated in the void space in the freeflood area in the casing under the deck. From this yoke the two rudder rods goes in the freeflooded area to the yoke of each rudder, the two rudder stocks goes in two pipes down to each of the rudders. Thus primarily in the free flood area outside any tanks after leaving the pressurehull.
Tore

Don Prince · « **Reply #4281 on:** 11 Apr , 2020, 00:35 »

Hello Mr. Tore,

I could not find an answer to my question about how the pedestal drive rods got to the dual rudders and through MBT 1 in the Type VII C diagrams. However, the Type VII D diagrams do show dual channels passing through MBT 1. In the diagram you can see the pedestal drive arms and the drive rods in the middle of the channels at Spt. -6 frame (See the attached drawing). Do my assumptions look to be correct?

Regards,
Don_

Don Prince · « **Reply #4282 on:** 11 Apr , 2020, 14:39 »

Hello Mr. Tore and All,

Let's hope for a Happy Easter and Passover; may the season of Spring renew and heal our world...

Kind regards,
Don_

Don Prince · « **Reply #4283 on:** 12 Apr , 2020, 19:47 »

Hello Mr. Tore,

I found this photo of KNM Kya on the internet... I can see the Norwegian designed tower/winter garden.

Regards,
Don_

tore · « **Reply #4284 on:** 12 Apr , 2020, 23:46 »

Don. I never saw the photo, but I am pretty sure it is from my time. I know the guy very well, both from the naval academy and later. I am probably on the bridge.
Tore

Don Prince · « **Reply #4285 on:** 17 Apr , 2020, 21:50 »

Hello Mr. Tore,

I have a question about the drive shaft to open the vent valve for MBT 1... The hand wheel is located on the control room aft pressure hull on the Port side.

1. The 1st photo shows the diesel room with the MBT 1 drive shaft RED on the port side. The cream colored shaft with a RED hand wheel controls the MBT 2 aft vent valve on the starboard side (this shaft goes to a bevel device to activate the dual vent valves for MBT 2).

2. The 2nd photo shows the drive shaft for MBT 1 vent valve coming through the bulkhead on the starboard side.

I don't see any cross-over of the MBT 1 drive shaft in the diesel room??? Do you have a better photo?

Regards,
Don_

tore · « **Reply #4286 on:** 18 Apr , 2020, 07:06 »

Don.
No wonder, it is hard to discover. Just aft of the fuel daytank, settlingtank, and fore of the pneumatic exhaustvalve grinding machine is a chaincasing containing a chaindrive of the rod from port to starboard. I have superimposed in red the item and if you look carefully at the image you might be able to see the cage.

Tore

tore · « **Reply #4287 on:** 18 Apr , 2020, 07:15 »

Don. May be this image with less text makes the chaindrive easier to discover.
Tore

Don Prince · « **Reply #4288 on:** 18 Apr , 2020, 14:58 »

Hello Mr. Tore,

Thanks for resolving my MBT 1 vent valve drive rod issue! I don't believe we ever discussed the drive chain before, but again I never asked the question... You are the man!

Regards,
Don_

Don Prince · « **Reply #4289 on:** 18 Apr , 2020, 23:08 »

Hello Mr. Tore,

I was able to get a fairly good image for my Skizzenbuch "Addendum Booklet"...

Regards,
Don_

Don Prince · « **Reply #4290 on:** 04 May , 2020, 20:16 »

Hello Mr. Tore,

What if U-995 was submerged and a depth charge attack resulted in the support A frame on the port side was completely broken and there is no support for the port drive shaft and propeller. And to make it more interesting, the starboard diesel engine has a damaged #1 cylinder liner and piston and you have no spares...

When you finally surface; you can't just row the U-Boat back to your home port.

1. You could pull the piston drive arm, disable the injection pump and run on the other 5 Cylinders, but the engine would be terribly out of balance.

2. Would you pull the piston rods for all cylinders in the block with the damaged piston and liner, and run on the other 3 cylinders which would be balanced on the crank shaft?

Regards,
Don_

tore · « **Reply #4291 on:** 04 May , 2020, 23:59 »

Don. May be the ultimate solution would be to rise the periscope, collect the bed clothes and make a sail. I am not sure if the crew would sacrifice their bedclothes though. In that case I would try to run on 5 cylinders, charging the batteries and use the E-motors limping home. I don`t see the point in dismantling the other moving parts in the engines. When the propeller shaft is damaged go back to the ultimate solution.

Tore

SG · « **Reply #4292 on:** 06 May , 2020, 01:44 »

Don Prince · « **Reply #4293 on:** 07 May , 2020, 01:23 »

Hello Mr. Tore,

Perhaps they could use the port diesel to charge the batteries and run on the starboard e-motor. I believe that would be making the best of the situation with these conditions.

What do you think?

I'll need to search and see if I can find out how U-45 (in the photograph) made it back with the damaged port side...

Regards,
Don_

tore · « **Reply #4294 on:** 07 May , 2020, 07:55 »

Don, as long as you don`t use your image as a reference for the situation, yes. Your image shows a damage which might involve a flooding of the E-room, with main motors and switchboard making same useless. Further a major intrusion of water in an end- compartment and MBT 1, approximately a total of 62m3 if filled and a trim moment of - 200.3 meter tonnes would create a dangerous situation which might require a compensation, which again might lead to a larger aft draft.
Tore

Don Prince · « **Reply #4295 on:** 08 May , 2020, 02:48 »

Hello Mr. Tore,

The documentation only states U-46 (not U-45) was attacked with a/s bombs, one of which was a direct hit on the stern, blowing a large hole in the outer plates. One crewman killed. U-46 returner to Kiel 29.10 40.

It looks like about 3 months later, back into action...

12.2.41 Left for the North Atlantis, to operate between the Shetlands and the Faros. U-46 returned to base 4.3.41.

It looks like the starboard side was OK to get back to Kiel for repairs...

Regards,
Don_

Raymic1 · « **Reply #4296 on:** 22 May , 2020, 14:17 »

Hello Mr Tore
I hope you are keeping well.
Apologies if you have discussed this before but having served both on Type VIIc and a Type VIIc\41 you are in a unique position to answer my question.
As not many interior detailed pictures exist of Type VII/c we only have U995 Type VIIc/41 Kaura to show us detailed interiors.

It is written that the /41 had a stronger hull had the same Engines but was made lighter by less heavy internal equipment to compensate.

Although U995 Kaura had slight Norwegian modifications (and all the present day colors are incorrect) can you advise what major internal equipment was different on U995 from a Type VII/c.

Both the subs you served on were middle to late war. U926 and U995

For example a major internal change on the Type VIIc was the Electrical Switchboard going from a an Early war Round Type U552 to a Rectangular Type as seen in U995.

Thank you. Stay safe.

tore · « **Reply #4297 on:** 23 May , 2020, 09:13 »

Raymic1

Thank you for the good wishes, going on 92 takes its toll but I guess I should`t complain. Making a survey of all the modifications and years on the VIICs

would probably be a task for a historian rather than an engineer, in fact the development of the VII class has been a continious process from the very beginning. However

if we concentrate on the step from the first ordinary VIIC to the VIIC/41 you are right, the increased max. crush depth was the main thing. This was achieved by increasing the steelplate thickness particulary in the tower and controlroom area. This of course influenced the deplacement which implied a reduction of weigth. The weight reduction was obtained by doing a lot of modifications in the engineroom. By making the diesels nonreversible the heavy reversing mechanism was removed, the most visible item is the vertical reversingcylinder on top of the engine, up front. Then likewise the lubeoil purification plant. By introducing the non reversible dieselengine the surface maneuvring had to be substituted by a simpler main switch board. The switch board on all our VIICs ( ex U 995, U-926 and ex. U 1202 were all alike as all the main engines were the same. The U-995 had quite significant flare, ( Atlantic bow), the other less. Contrary to many images the U 995, U 926 and U 1202 had a ringfloat air valve on top of the snorkel mast, not the hinged type as on the museum U 995 today. As you might see there are a lot of minor differences within the VIIC class, some time you have the feeling that several yards made, within limits, their own design, particularly in the latter part of WW2. U 995 never operated with snorkel in WW2, in fact she was at the yard installing the snorkel at the surrender.
Feel free to ask further questions.
Tore

Don Prince · « **Reply #4298 on:** 24 May , 2020, 16:43 »

FYI....
Don_

Skizzenbuck Page 106

"U-Boat Type VII C/41 Pressure Hull Construction

The Type VII C design was subjected to a weight loss program by using lighter machinery wherever possible, and lighter electrical components (i.e., the e-motor rotary switchboard control panel replaced the heavier toggle switchboard control panel). The results were a weight reduction of 11.5 tons which meant they could increase the thickness of the pressure hull in the Type VII C by 10 tons. For example; the control room hull thickness was increased from 18.5 mm to 22 mm. The test diving depth (60% of the crush diving depth) increased from 150 m to 180 m, and the destruction diving depth increased from 250 m to 300 m. This altered Type VII C construction plan was designated the Type VII C/41 because it was approved in 1941 (this was only a modification of the Type VII C and did not introduce delays in the intermediate size U-Boat building program for the contracted manufacturers). The major reason for this plan was to allow the Type VII C/41 U-Boat to avoid ASDIC/SONAR detection by diving so deep as to weaken the return ping reception to look as background noise."

In Addition:
1. Degaussing cabling longitudinally around the pressure hull and casing was removed in the late 30's to early 40's
2. The two (2) external torpedo storage tubes were no longer utilized under the deck (reduced from 14 to 12 torpedoes)
3. The 88mm cannon was removed and the need for the shell storage
4. The ASDIC/SONAR - S-Gerat equipment development was dropped (reason for the longer Control Room in VII B to VII C). This
space was later used for RADAR equipment.

Regards,
Don_

Raymic1 · « **Reply #4299 on:** 24 May , 2020, 22:07 »

Don and Tore
Thank you for this fantastic information.

In regards the Switchboard color. The general interior of the Rear Torpedo area was Ivory and all the wartime and postwar photos of Rotary (U552) and Rectangular (U995 Kaura) Switchboards looks a White color with Black controls. Or maybe it is a very light grey?

Even though U995 museum colors are now medium grey.

So would White with Black controls be correct for Wartime?

Also if White was there any reason for this color when most other equipment was a generally a shade of Grey?
Thanks.

tore · « **Reply #4300 on:** 25 May , 2020, 00:54 »

Raymic1
The general impression of the VIIC interiors is grey and the machinery a slighter darker shade of grey. I guess the impression of Ivory on the black and white photos could derive from the reflection of the flash. The fancy green colours as on the main engines on museums U 995 might be a postwar influence from the commercial fleet as they used very often such colours. As space was a problem you did not stock a big selection of paint containers. The switchboards were light grey and the manoeuvre-wheels (switches) black. A big variation of colourstripes could be seen on the pipes, they were the colours codes use for identification for the various pipes as can be seen on the plate below.
Tore

Katuna · « **Reply #4301 on:** 27 May , 2020, 11:15 »

Does anyone know if there is a color version of the pipe identification code plate?

tore · « **Reply #4302 on:** 28 May , 2020, 00:58 »

Katuna.
We did not use the German colourcode for the pipings, but I have a short (and incomplete) explaination of the system which migth be of some help.
Tore

Katuna · « **Reply #4303 on:** 28 May , 2020, 06:12 »

Thank you Tore, I really appreciate it.

I remember seeing a reference to a color version of the German codes in my research but I never found it. It's out there somewhere. Would add a nice detail, as well as a little bit of color to the model.

Raymic1 · « **Reply #4304 on:** 11 Jun , 2020, 15:50 »

Hello Mr Tore. I hope you are well.
For over 8 years it seems you have been sharing your photos and notes. For this we heart-fully thank you.It had been fantastic in-site into your first hand accounts of life on a Type VIIC.
I was just wondering.
As has been discussed for some reason hundreds of early pictures have disappeared from your Posts or can no longer be opened which is a bit frustrating when we read the early posts.
At your convenience I wonder if you could just randomly reload any and all pictures you may like to share again? They don't have to be in any order.Any picture or any Uboat subject no matter.
I don't want to make it an onerous task for you, just what you feel like sharing in your own time would be fantastic to add to the history of the Uboat story.
Thank you
Mike
New Zealand

tore · « **Reply #4305 on:** 11 Jun , 2020, 23:28 »

Raymic 1
Thanks for your post and a good idea. Quite a few of my images can be found in Dons Skizzenbuch however a few of my earliest are missing. As they are one of a time images published for my posts only, they dissappeared when they were posted. I`ll go through my files as from my earliest posts and see if I can relocate same and publish some at irregular intervals. I regret I didn`t make a proper imagefile from the very beginning.
Tore

Raymic1 · « **Reply #4306 on:** 13 Jun , 2020, 20:15 »

Quote from: Katuna on 27 May , 2020, 11:15

Does anyone know if there is a color version of the pipe identification code plate?

The color version is in Darkstars new post book. Skizzenbuch fur das Maschinenpersonal..............................................................

Click on the Imgur link and download 97 pages!!!!!!!!! Thanks Darkstar

tore · « **Reply #4307 on:** 14 Jun , 2020, 00:37 »

Mike.
Exellent find! I guess some of the modelbuilders are able to put some colours to the interiors now provided they know the systems.
Tore

Don Prince · « **Reply #4308 on:** 14 Jun , 2020, 02:09 »

Hello Mr. Tore and Mike,

Do you have access to the entire Mechanical book? It would be nice to compare it to the U-570 Mechanical book on Jerry Mason's website...

Regards,
Don_

Raymic1 · « **Reply #4309 on:** 14 Jun , 2020, 03:49 »

Darkstars post didnt explain very well below but f you click on the link in Darkstar130 post below it opens in the app Imgur or Chrome.
I then copy and pasted 90 plus pages one at a time. Here's his link here

https://imgur.com/a/bZAqp5v

Im not sure if I can load the 90 plus pages in one go.

Don Prince · « **Reply #4310 on:** 14 Jun , 2020, 15:48 »

Hello Mr. Tore and Mike,

Thank you for the link to the mechanical book... I have cleaned up the piping color coded chart and translated. See the two (2) attached images...

Regards,
Don_

Raymic1 · « **Reply #4311 on:** 14 Jun , 2020, 17:06 »

Thanks Don. I tried to google translate and it didn't work very well.

Have you seen this book before? It looks like an original WW2 document. And it would seem that quite a few of its pages have been replicated over other documents over the years.
I'm not sure where Darkstar130 got it from

Lots of info in there.
Is there any other stuff on the 90 pages that is useful for your Skizzenbuch?

Don Prince · « **Reply #4312 on:** 14 Jun , 2020, 21:02 »

Hollo Mr. Tore and Mike,

Yes, this looks like a image copy of an original Mechanical book using a modern color copy machine. The copy of the U-570 Mechanical book used a mono-copy machine back in the days. However, Capt. Jerry Mason cleaned up the U-570 mechanical drawings and that is what was used in Skizzenbuch. The Plan 3 color code page was not clear (black/white/shades of grey) so we had no idea as to the actual color of the coded pipes. Maciej Florek was going to work on the piping color coding, but fate ended that project.

I will add the color Plan 3 to the Skizzenbuch Addendum Booklet that I plan on releasing late this year...

Regards,
Don_

tore · « **Reply #4313 on:** 14 Jun , 2020, 23:15 »

Don.
I guess it is an asset to the Skizzenbuch, I wish we would have these plates in my days onboard, we had to learn it the hard way, crawling and making our own sketches in addition to the poor quality sketches available.

Tore

Don Prince · « **Reply #4314 on:** 15 Jun , 2020, 02:34 »

Hello Mr. Tore,

Didn't U-995 have the original factory mechanical and electrical books onboard? They were supposed to accompany each U-Boat when they were commissioned. Did the crews dump those books along with the enigma machine and code books before surrendering the U-Boats? Apparently, the British got all that documentation and the enigma machine when they captured U-570...

Regards,
Don_

tore · « **Reply #4315 on:** 15 Jun , 2020, 04:41 »

Don.
As a part of the german surrender agreement the majority of the operational german submarine fleet, about 100 submarines of all types, came to surrender in Norway. Those which were seaworty were later ordered to sail to Scotland as a part of the surrender agreement to be destroyed. This operation was called Operation Deadlight and agreed between the USA, Russian and British forces during the Jalta conference and later the Potsdam conference just at the end of the WW2. The german submarines were ordered to sail to Scotland with their original crew, flying a black flag. Those few submarines being not seaworty remained in the fjords and most of the documents disappeared. The norwegian navy eventually was able to produce som manuals in the norwegian language, in my time we had to make our own notes waiting for complete manuals.

Tore

Don Prince · « **Reply #4316 on:** 15 Jun , 2020, 13:30 »

Hello Mr. Tore,

When you got your submarine training in the UK; was it in English or the Norwegian language? I would assume it was in English. You seem to have some knowledge of the German language since you have provided some greater depth of understanding of the German schematics. When did you pick up the German? I would think that the original German mechanical and electrical documents would have been a great help when you was the onboard EO...

Regards,
Don_

tore · « **Reply #4317 on:** 15 Jun , 2020, 14:17 »

Don.
My submarine training at HMS Dolphin, Gosport, Portsmouth was of course in English, but I grew up in a German occupied country were our normal english education was substituted by German. I guess, for me, some of the German language sometime is easier when it comes to submarine techniques and dieselengines in spite of having done my training in UK. I didn`t have any problem with the German documents on board the U 995.

Tore

Katuna · « **Reply #4318 on:** 16 Jun , 2020, 08:28 »

Don - Thanks for cleaning up the color index. Just downloaded all of the pages that were posted by Darkstar. Those will be a huge help whenever I can get back on my build.

Don Prince · « **Reply #4319 on:** 17 Jun , 2020, 01:55 »

Hello Katuna,

Jerry Mason's website www.uboatarchive.net has Plan 5: General Arrangements (Two U-Boat Drawings) which were missing on the colorized prints website (Just Grey Schematics) and now you will have a complete set.

See the Attachments...

Regards,
Don_

Katuna · « **Reply #4320 on:** 18 Jun , 2020, 07:50 »

Thanks for posting those Don. I think I have the German version somewhere in all my info but not the English. It's great to see (and have) a complete book.

Don Prince · « **Reply #4321 on:** 21 Jun , 2020, 18:47 »

Hello Mr. Tore,

I was thinking about the external canisters that held the spare torpedoes below the deck... The G7a torpedo weighed about 3,369 lbs and the G7e weighed about 3,534 lbs; a torpedo canister would displace about 4,032 lbs of water. So, I figure with the weight of the canister and the air space at the end-points of the torpedo in the canister; there was about neutral buoyancy on the loaded tubes below the deck. The G7a (T1) torpedo had a negative buoyancy of about 605 lbs and the G7e (T2 and T3) was about 597 lbs negative buoyancy.

However, my first thought would be when the torpedoes were moved inside the pressure hull, then the torpedoes weight is still on the U-Boat, only now inside the pressure hull. When the torpedo is fired, then the water from the torpedo tube is drained into a torpedo trim tank. Therefore, there is no weight change on the U-Boat. You now have the water in the torpedo trim tank countering the emptied torpedo canister below the deck weight loss.

Did they seal the canisters after removing the torpedoes?

Then the weight has not changed on the U-Boat; the torpedo was just moved inside the pressure hull. When the torpedo is fired, then water from the torpedo tube is pumped into the torpedo trim tank to maintain the balance and the U-Boat's trim line.

However, I would think if they closed the canisters, then there would be two (2) sealed canisters containing an air bubble creating a diving issue.

I believe this would be a lesser issue with the Type VII U-Boats with just two (2) external torpedo canisters, but on a Type IX U-Boat with ten (10) torpedo canisters where this could create a serious diving problem...

What do you think...

Regards,
Don_

tore · « **Reply #4322 on:** 22 Jun , 2020, 01:36 »

Don.
Weight changing is a never ending story of a submarine operation, this refer not only to torpedoes, but consumables like all the items which involving the needs of 46 persons during weeks. There are many ways the weights influences the behaviour of the vessel, like the trim moments ( alongship distances from the centers of gravity) and heights ( stability, metacentric heights.). In case of liquids, free surface effect might create problems. Hence 100% water compensated fueltanks were used. Thus a number of elements are involved. Generally you are able to control a submarine dynamically ( by speed and hydroplanes or/and by filling and draining trim tanks. In order to simplify the matter you have general rules like compensating for free surface effect by having containers either completely full or empty, using experience by compensating weight movements inside the pressurehull, like shifting crew from nightmode to battlestations (divingstations). On the U-995 you had to pump 400 ltr water from aft trimtank to fore. We did away from the torpedo containers in the casing, but should assume they would be flooded unless the weather would be bad and hence it could be a stabilityproblem surfacing ( critical just breaking the surface ). If you were entering hostile waters you would fill the Q tanks ( untertriebdzelles) to be able to dive quickly. As so many others things in life, experience rules and the COs judgment was the base of the procedure. In fact you could not make strict rules unless you involved the whole picture of the mission of the submarine, as one step would interfere the others.
Tore

Don Prince · « **Reply #4323 on:** 22 Jun , 2020, 02:14 »

Hello Mr. Tore,

If the External Torpedo tanks (Aluminum) were open, then they would flood when diving and emptied when on the surface and not creating a problem in bad weather...

Thanks again, Regards,
Don_

Don Prince · « **Reply #4324 on:** 29 Jun , 2020, 20:37 »

Hello Mr. Tore,

I was online with a model builder and he had what looked like rain gutters on his U-Boat (U-995) and the diesel exhaust looks to be wrong as well. I have attached a few photos... What do you think?

He also has a diesel exhaust like the last photo...

Regards,
Don_

Don Prince · « **Reply #4325 on:** 30 Jun , 2020, 00:18 »

Hello Mr. Tore,

Do you have any photos that show the blister on the port side casing for the schnorchel air intake, and the exhaust piping above the deck in the starboard side. Marcus, the model builder seems to believe the all was under the deck on U-995 (Laura S-309)?

Regards,
Don_

tore · « **Reply #4326 on:** 30 Jun , 2020, 00:53 »

Don.
It is not easy to preserve a full open air monument like U-995 for many years unless you take corrosion precautions deviating from the original. One of the big problems are corrosions between the casing and pressurehull, hence the drain holes and the gutters on the museums U-995. I dont think the drainholes are made through the pressurehull The drains have been modified many times through the years as can be seen on my image below. Another issue is the corrosion of the pressure hull derived from galvanic corrosion while the U-995 was "stored" afloat without sacrificing elements. leaving serious caverns in the pressurehull. I really don`t see the point in copying these corrosions on a VIIC model as in such condition the VIIC would not be seaworthy. Another tendency is to exaggerate the tiny rivets in the casingplating, which sometimes gives the model a look of a tank from WW2.

Tore

tore · « **Reply #4327 on:** 30 Jun , 2020, 01:37 »

Quote from: Don Prince on 30 Jun , 2020, 00:18

Hello Mr. Tore,

Do you have any photos that show the blister on the port side casing for the schnorchel air intake, and the exhaust piping above the deck in the starboard side. Marcus, the model builder seems to believe the all was under the deck on U-995 (Laura S-309)?

Regards,
Don_

Don.

In may 1945 U 995 was installing her schnorchel at the submarine base in Trondheim, here is an image showing the final stage of the installation with the airelbow in the casing is protruding out from the casingside, this is the only part of the snorchelair inlet pipe out of the casing, the remainder is inside. Remark the float on the top of the mast has a ringfloat whereaes the present museums U-995 has a hingefloat.

Tore

tore · « **Reply #4328 on:** 30 Jun , 2020, 01:41 »

Quote from: Don Prince on 30 Jun , 2020, 00:18

Hello Mr. Tore,

Do you have any photos that show the blister on the port side casing for the schnorchel air intake, and the exhaust piping above the deck in the starboard side. Marcus, the model builder seems to believe the all was under the deck on U-995 (Laura S-309)?

Regards,
Don_

Don.

In may 1945 U 995 was installing her schnorchel at the submarine base in Trondheim, here is an image showing the final stage of the installation with the airelbow in the casing is protruding out from the casingside, thisis the only part of the snorkelair inlet pipe out side the casing, the remainder was inside. Remark the float on the top of the mast has a ringfloat whereaes the present museums U-995 has a hingefloat.

Tore

Don Prince · « **Reply #4329 on:** 30 Jun , 2020, 01:55 »

Do you remember if the exhaust piping was above the deck?

tore · « **Reply #4330 on:** 30 Jun , 2020, 02:44 »

Don.
Here is the schnorchelsystem, the yellowpart of the exhaust is protruding up on the casingdeck to allow place for the exhaustblowing panel, the valves are, as you know, operated inside the pressurehull in the controlroom.
Tore

tore · « **Reply #4331 on:** 30 Jun , 2020, 03:09 »

Don. An image of KNM Kaura ex U-995 1953 where the Schnorchel exhaustbend is clearly seen on the casingdeck.
Tore

Don Prince · « **Reply #4332 on:** 05 Jul , 2020, 02:20 »

Hello Mr. Tore,

I found a very early photo on the subcommittee.com website of U-995 and I'm now not sure about the 'Drip Line". The original photo of U-703 looks like perhaps like a "Drip Line" existed? However, the early photo of U-995 leaves me unsure... Perhaps they closed the "Drip Line" during the restoration, and then they decided to re-add the drainage later after they seen a water buildup... What do you think?

Regards,
Don_

Don Prince · « **Reply #4333 on:** 05 Jul , 2020, 03:01 »

Hello Mr. Tore,

After blowing up the image, it looks like when they rebuilt U-995 that they plugged up the "Drip Lines" with small rectangular patches (welded over the drain slots)... Then when they ran into water backup issues, they cut rectangular holes in the casing and added the gutters. What do you think?

Regards,
Don_

tore · « **Reply #4334 on:** 05 Jul , 2020, 07:59 »

Don.
I wouldn`t trust the present execution of the museums U 995 as there are many modification related to the safety of the visitors. F inst. the foreship floodgates are welded shut due to people starting to climb the casingside. The image you are posting seems to be of the welded type casings, the original is riveted. I cannot remember the details 100% but am reasonable sure there were no "gutters". The aft fairings of the saddletanks on some VIICs were equipped with floodgates as shown on my image.
Tore

Don Prince · « **Reply #4335 on:** 05 Jul , 2020, 14:47 »

Hello Mr. Tore,

The last photo posted has a description as "Floodgates fairing VIIC u421ausecondplantoulon.jpg"

aus = aus / Form
econd = second
plan = plan
toulon =

Does the title mean "Flood Gates Fairing VIIC" and "U-421 second plan" and the photo is from "Toulon, France"?

Regards,
Don_

tore · « **Reply #4336 on:** 06 Jul , 2020, 00:13 »

Don. I guess the images are from a french contributor to a uboat thread and showing U-421 damaged in the drydock in Toulon, France.

Tore

tore · « **Reply #4337 on:** 15 Jul , 2020, 11:15 »

We previously discussed the colour markings of the pipings as used originally. Unfortunately the frequent painting of the engineroom was carried out ad lib and eventually all the orginal paintings disappeard. As previously told we didn`t use this system, but I have an image of the engines of KNM Kaura ex. U 995 in my time showing the marking of the fuel pipes as fitted up front of the main engines. An interesting detail is the valve rocker rods, today painted blue, are on this image still not painted and hence shiny steel.
Tore

Katuna · « **Reply #4338 on:** 15 Jul , 2020, 11:31 »

Tore - Thank you for the info. Would make sense that marking would be near either end of their run.

tore · « **Reply #4339 on:** 16 Jul , 2020, 00:24 »

Katuna, further to my post yesterday, here is another image of the colourmarking up front of the main engines, showing the fuel and and lubeoil pipes markings
Tore

Katuna · « **Reply #4340 on:** 16 Jul , 2020, 07:52 »

Thanks again. I've been trying to find photos from back during the war but they are very hard to come by.

Raymic1 · « **Reply #4341 on:** 20 Jul , 2020, 05:51 »

Mr Tore
Are you in this Norwegian movie about Kaura S309 U995?
Click the link below

https://m.youtube.com/watch?v=05XQ_oOS4lo&feature=share&fbclid=IwAR17vc2kZETLDhw_WedvJKh4HvpLA30eEBgNCeISgp4i_q5x0o1tbWZgBps

tore · « **Reply #4342 on:** 20 Jul , 2020, 07:19 »

Raymic1, I never saw the movie and I guess it was shot a few years after my time. The CO (ltn.commander) in the movie graduated a year before me at the naval academy and later became the CO of KNM Kaura when she served as a training sub when our main submarine base moved to Bergen in 1954. Very interesting to see a colour movie of KNM Kaura ex U 995 from this time. As to the scene in the engineroom you`ll see the correct colour of the paintings of the dieselengines. Some of the engineers participating were serving as my engineers in my time. PS. we never were dressed in uniform and white shirt as the officers in the movie, I guess it`s done for the moviemakers. We usually dressed in uniform when we had journalists making a submarine story onboard, like the image below, where I make some target distance calculations based on the COs report from the navigation periscope. This was just a show for the paperpeople. Thank you for sharing the movie.
Tore

Katuna · « **Reply #4343 on:** 20 Jul , 2020, 17:03 »

What a great find on the film. In color no less. I was really happy to see the engine color I chose is almost spot on. I think it's Tamiya IJN grey, A little greenish grey. Great to see the girl in action.

Don Prince · « **Reply #4344 on:** 29 Aug , 2020, 01:44 »

Hello Mr. Tore,

I have uploaded the latest version of the Addendum Booklet P.pdf into dropbox and you still have the permissions to download the file. If you have some time would you please review what I have created. It's 43 pages of text and mostly photos... I highly value your input...

FYI - I had another heart problem for about a week before it went away. My doctor did a PET (Nuclear) stress test and they don't see any reason for the chest pain. He changed my meds to lower my blood pressure and said if it happens again I may need to go to the hospital and have another heart catheterization done (they inject a shell fish die into your heart arteries to check for blockages and take images)...

Regards,
Don_

tore · « **Reply #4345 on:** 29 Aug , 2020, 02:08 »

Hi Don.
Sorry to hear about your health issue, a youngster like you should`t experience the trouble. As for me I`m going on 92 and am currently on my summerfarm in the deep forrest with very limited access to internet. Apart from my hearing being destroyed by the engines of the old U 995 and a minor stroke, I am doing OK for my age I guess. I shall revert to your request as soon as I am back to the civilization. Keep on going, you have still to accomplish your mission.

Tore

tore · « **Reply #4346 on:** 04 Sep , 2020, 01:44 »

Don,
I have read your last additional pages of your Skizzenbook and have following remarks as to my remarks: Page 24 plan 13 seacoolingwater somehow a misunderstanding occur in the description of the seacooling crossover pipe. The main seawater intakevalves are not air activated, the airsupply indicated on plan 13 is for the seaweed blowing, to clean the intake for seaweed, the seawater intake valve is a manual operated valve.
Page page 27, galvanic sacrificing anodes. On the image of the anodes of U 995 they are painted, the anodes should never be painted as they are sacrificing elements.
Otherwise the pages concerning my remarks seems to be OK.

Tore

Don Prince · « **Reply #4347 on:** 06 Sep , 2020, 20:08 »

Hello Mr. Tore,

I corrected page 24 and page 27 accordingly... I had to rebuild the Addendum Booklet folder in my Dropbox account and I would like you to check it out. The correction and to see that you have full access to the rebuilt folder... I think I got all the permissions correct??? I tested a Dropbox Business option (15 day free trial) and that changed the permissions and was almost a disaster when I went back to the standard free Dropbox account option.... I'll never do that again!

Regards,
Don_

Questions:
1. Can the inlet valve be cleared with compressed air before the inlet valve is opened?
2. Is there ever a need to clear the inlet valve when running on the surface?
3 Is there a pressure gauge on the engine control panel monitoring the inlet water pressure?
4. Where were the sea water inlet valve and compressed air blowing valve hand-wheels located?

tore · « **Reply #4348 on:** 07 Sep , 2020, 01:02 »

Don. 1. You blow to clean the intake for the seawater valve prior to it is opened as you don`t want to blow air into the coolingwatersystem.
2. It is always a need to clear the inlet by air running on the surface, particulary at present days plasticpollution. I have experienced a full
shut down on a passengercruiser due to a floating plastic sheet blocking the coolingwater intake.
3. Apart from the general LP manometer there is no local manometer for the LP seaweed cleaning.
4. The seawater inlet and grating with LP connection (called the inletchest) is located in the pressure hull between the sea and the
valve. The LP air pipe and valve is of a relative small dimension.

Tore

tore · « **Reply #4349 on:** 07 Sep , 2020, 02:50 »

Don, below are some images of the seaweed blowing. N0 1 the grating in the pressurehull and the sea boardvalve with Lp blowing system as fitted in the engineroom of the museums U995.
Tore

Don Prince · « **Reply #4350 on:** 08 Sep , 2020, 02:06 »

Hello Mr. Tore,

When the U-Boat is on the surface or schnorchelling...

The hull/sluice valves in the diesel room can provide cooling water for both diesel engines and cooling water to the e-room for the e-motor coolers, e-motor bearings, thrust bearings, e-compressor, and the junkers compressor (if present). The diesel engine's cooling water returns to the sea via the diesel exhaust muffler vents, the header tank, the exhaust muffler exit ports on the Junkers compressor (if present), and the open Starboard hull/sluice valve in the e-room.

When the U-boat is running submerged...

The Port hull/sluice valve is providing the cooling water to all said components in the e-room, and the sea water is returned to the sea via the open Starboard hull/sluice valve in the e-room. I believe this source for cooling water also feeds forward though the diesel engines and some may exit to the sea via the diesel mufflers and the header tank...

MY Question Is...

In all instances; running on the surface, schnorchelling, or submerged - The e-room Starboard hull/sluice valve is open and draining circulated cooling water to the sea. What would be the reason for ever shutting this valve? It looks like components in the e-room require this valve to be open; including the thrust bearings???

Regards,
Don_

tore · « **Reply #4351 on:** 08 Sep , 2020, 07:12 »

Don.
The intake of seawater is usually controlled by opening and shutting of boardvalves. In general all valves beween the sea and the inner part of the pressurehull is controlled by a valve having a circular valvedisc . All the valvediscs of the seavalves are opened against the seapressure, hence the seapressure keeps the valvedisc shut on the seating. As this design usually involves friction and a capacitydrop, these valves are primarily used as seaintakevalves. The seawater system inside the pressurehull is usually fitted with ordinary valves with circular valvedisks as well. The exception is the large capacity crossover supply pipe which is fitted with freeflow gatevalves and the lesser distribution branches from the crossover with ordinary valves having valvediscs.

There are several cases you need to shut the seaboard valves. In the event of a deep dive and depth charge attack the procedure of the order: "prepare for depthcharge attack or deepdive" involves shutting of the seaboard valves.
Hence as a rule you always want to have a double security on the boardvalves.

Tore

Don Prince · « **Reply #4352 on:** 08 Sep , 2020, 14:36 »

Hello Mr. Tore,

Do you have a drawing of a circular valve disc assembly?

From what data I see on the e-room cooling water pump, the stats are:
Centrifugal Type
250/385 liters/minute
12 atmospheres head pressure

If the U-boat goes to a depth of 150 meters... The pressure at the e-room Port and Starboard valve heads would be 14.51 atmospheres. Therefore, the CW Pump sees no restrictive head pressure (equal pressure at both sides input and exit), so the pump can normally function and supply CW to the internal needs of the U-boat.

However, I do believe there would be a pressure differential seen between the water lines internal pressure and the U-Boat's internal atmospheric pressure. In the movie Das Boot you saw water lines bursting and rivets popping when the U-Boat plunged below 200 meters...

I definitely see a need to close the valves during a depth charge attack because of the possible differential pressures depending upon the explosion location relative to the U-boat.

Are you aware of any reported damage to the CW Pump, CW intake valve, CW exit valve, due to a depth charge attack?

Other than the attached photo...

Regards,
Don_

tore · « **Reply #4353 on:** 09 Sep , 2020, 01:27 »

Don the capacity of a centrifugal pump is following the QH graph as the design of the impellor, hence a given certain capacity is always followed by the head. Below is a typical drawing of a seaboard valve (As I couldn`t find a proper engineroom board valve, it`s belonging to the torpedotube system) which I guess speaks for itself, followed by a drawing which shows the internal freeflow of a gate valve. The most common reaction to a high pressure in the internal system is blowing of flangepackings and stuffingboxes.

Tore

Don Prince · « **Reply #4354 on:** 10 Sep , 2020, 02:43 »

Hello Mr. Tore,

I have been looking closely at the e-room Port hull valve and it looks like the hull valve is bolted to a plate that is welded to the pressure hull. Also, the hull valve vent grill looks to be screwed to the welded plate as well. See the two images...

Regards,
Don_

Don Prince · « **Reply #4355 on:** 12 Sep , 2020, 21:32 »

Hello Mr. Tore,

When you dive the U-boat both diesel engines are stopped so the attached cooling water pump has stopped. However, I believe you still need to cool the diesel engine. Therefore, the cooling water pump in the e-room looks to be able to provide cooling water to both diesel engines if you opened valves e1 in the valve chest, or you could use the auxiliary cooling water pump in the diesel engine room?

1. On a dive did you normally shut both engine room hull cooling water intake valves and use the valve chest and open valves e1 to provide cooling water to the diesel engines and then shut valves e1 after the engine were cooled down?

2. I would think that you would not want to use the diesel room's auxiliary cooling water pump to cool the diesel engines during a dive because now the control for powering the U-Boat is in the e-room.

Second thought!

If the U-Boat goes very deep and is under a heavy depth charge attack... Could they close all hull valves and stop all water cooling to the e-room to protect the U-Boat from bursting pipe flanges, etc... Now they could run the e-motors at creep/crawl speed and hopefully not over heat the thrust bearings or the e-motor bearings. Do you know if this is a possibility?

Regards,
Don_

tore · « **Reply #4356 on:** 13 Sep , 2020, 00:57 »

Don, normally it is up to the first engineer to decide the various components to operate as it all depends on many variable like maintenance, weather,mission etc. The various systems however are very flexible and allows many alternatives. Unfortunately some of the systemsketches are not correct as plate 13, showing the coolingwater system for the GW dieselengines. On the enclosed plate 13 I have corrected the crossover pipe allowing stb engine and the aux. coolingwaterpump to take suction from the pipe. In general this pump will be used for the diesels instead of the E room coolingwater pump.

Tore

tore · « **Reply #4357 on:** 13 Sep , 2020, 01:08 »

Don, your last question: in emergency you do anything and I dont think at dead slow speed, major damages occur to thrustbearings, E-motor bearings etc. in case of seawater cooling is shut.
Tore

Don Prince · « **Reply #4358 on:** 13 Sep , 2020, 13:21 »

Hello Mr. Tore,

Yes I was aware of the connection on Plate 13... I have attached the Skizzenbuch modified drawing and I noted two (2) locations with a RED circle on the print.

It's good to know that the diesel room auxiliary CW Pump was used to continue cooling the Diesel engines. Do you remember how long that process would last? I would not believe it took too long...

Regards,
Don_

Don Prince · « **Reply #4359 on:** 30 Sep , 2020, 18:48 »

Hello Mr. Tore,

I have attached below a photo of the various diesel exhaust arrestor on Kaura (ex U-995) and others:

1. If the exhaust exits the spark arrestor above the water line is there a staring black smoke?
2. If the exhaust exits the spark arrestor below the water line is there a starting white smoke?
3. Was there ever a time when actual sparks were seen exiting the above the water line spark arrestor?

Regards,
Don_

tore · « **Reply #4360 on:** 01 Oct , 2020, 00:36 »

Don. The exhaust is usually an indicator for the condition of the engines like fuel nozzles and coolingwater leakages. Normally you would not notice any black or white exhaust. A bad fuelnozzle or overload would create a black exhaust and white smoke a coolingwater leakage like corrosion holes in the exhaustvalvecage. Nevertheless the exhaust would leave some deposits of black carbon at the exhaust outlets and you migth see some of the VIIC casings have been painted black just above the outlet to disguise the deposits. You very seldom see any sparks at the exhaust outlets.

Tore

Don Prince · « **Reply #4361 on:** 01 Oct , 2020, 23:14 »

Hello Mr. Tore,

Can You look at the attached image and answer the question between Simon and I???

Regards,
Don_

PS... Sometimes it may be a good idea to read my own book...

Exhaust Port and the Spark Arrestor

The VII Cs had a number of different exhaust outlets and possibly spark arrestors. The colleague of photos to the left shows 5 versions. The spark arrestors for U-Boats may be of two executions; wet or dry. The dry spark arrestor has an intricate system of baffle plates to arrest the sparks inside a casing. In the wet execution, the engine cooling water is sprayed into the arrestor or the gases are emitted into the water cooling well. In both instances they are placed above the water surface (sea). Another version is when the exhaust is emitted below the water surface (sea) without any special casing for a spark arrestor. The latter execution was the original U-995 design [Top right photo (RED circle) KNM Kaura/U-995 in dry dock in 1953]. This was changed on todays museum U995 as shown on the top left photo; the RED circled area indicates the Bold ejection port just aft of the rebuilt exhaust outlet location.

NZSnowman · « **Reply #4362 on:** 02 Oct , 2020, 21:32 »

Hi Tore & Don

A few questions about the Spark Arrestor and if it utilized cooling water.

* In the Design and Specification Books, Volume M on plate 13B, it shows no cooling water going pass the end of the diesel exhaust silencer.
* If it did spray cooling water into the Spark Arrestor, how was the amount of cooling water control?
* If cooling water was sprayed, this would lead to negative pressure in the cooling water system, does this mean they had to constantly add sea water to the system to replace the lose cooling water?

tore · « **Reply #4363 on:** 03 Oct , 2020, 02:27 »

Don and Simon.
As Don says there are a number of executions to the exhaust outlets in the casing, the execution I guess, might depend on the on the mission for the relevant boat. As on Dons image, the sparkarrestor is clearly visible adjacent to the silencer. Water spraying in the sparkarrestor is mainly a design for motorlaunches and I cannot remember it is used for the VIICs, a better solution would possibly be to end the exhaust pipe below the watersurface. The exhaust system is cooled by the main coolingwater system which leaves the pressurehull via the mantel of the main hullexhaustvalve with intricate passover the flanges up to and including the silencer. From the silencer the pipesystem end up in the fuelcompensating headertank in the towercasing having an overflow under the casingdeck to the sea, thus not visible. There are quite a few drain valves in the system allowing for draining the coolingwater mantels ( for artic operations). Below is an image showing the original exhaustoutlet in the casing as originally fitted on U 995 during the hand over October 2. 1971.

Don Prince · « **Reply #4364 on:** 03 Oct , 2020, 11:16 »

Hello Mr. Tore and Simon,

I do not believe we would ever see a negative water pressure in the cooling water system... Once the water compensation system is stabilized there is no further drain on the cooling water system because the diesel engines are drawing fuel from the day tank which is not water compensated. Therefore, the constant cooling water drainage is at the mufflers and at the header tank under the winter garden. Each engine mounted water piston pump can supply 48 cubic meters of CW per hour (the Electric Auxiliary CW centrifugal pump has the same capability). This definitely looks to be a pressurized cooling water system by design.

It looks like both U-995 and U-926 originally had the exhaust exit below the water line according to the shipyard and surface images. U-995 was converted to the exhaust exit above the water line during the museum refurbishment. This is one more item that they should have left as original!

Regards,
Don_

Don Prince · « **Reply #4365 on:** 04 Oct , 2020, 00:20 »

Hello Mr. Tore and Simon,

Sometimes I over think things, but I will just ask the question... This excellent Simon drawing shows the red pipe directing Cooling Water from the mufflers to the header tank. If only one (1) Diesel engine is running and CW is flowing to the header tank, it would also be back flowing CW into the opposite muffler. I believe if there was a one-direction check valve in each muffler line (or in the muffler itself), then this would eliminate the waste of Cooling Water.

If both diesel engines were running, then both supply CW to the header tank.

Question - Do you know if there was such a one-direction check valve in the muffler line?

Regards,
Don_

NZSnowman · « **Reply #4366 on:** 04 Oct , 2020, 00:51 »

Don, a good questions. I only guessing, I imagine some of the CW would escape but most would make it to the Header Tank.

I also have a question about the Cooling Water from the mufflers to the header tank.

I estimated the size of the two pipe coming out the mufflers at 75 mm. Does this mean that the pipe from the joint of the two pipes to the header tank is 106 mm (e.g. almost double the flow) or is it the same size pipe all the water to the Header Tank?

tore · « **Reply #4367 on:** 04 Oct , 2020, 02:14 »

Simon
As it is only a headertank I guess the pipe is 75 mm.
Tore

Don Prince · « **Reply #4368 on:** 04 Oct , 2020, 02:52 »

Hi Simon,

After looking at the Cooling Water line size (75 mm) and the obviously smaller size of drain lines placed at the top side of the muffler, I would think that the Cooling Water pressure would easily force CW up to the header tank (those drain lines at the top of the muffler also serve to get any air out of the muffler CW chamber). CW flowing from the muffler will keep the muffler temperature at an acceptable level depending on the outlet pipes diameter.

Just my opinion - I do not believe the pipe diameter is increased going to the header tank. The header tank serves as a reservoir for the fuel tanks water compensating system, and this system is only drawing water when fuel is being transferred to the day tank. So, you have CW overflow drainage at the header tank and CW drainage at the two (2) muffler drain pipes.

However, all is dependent on Mr. Tore comments...

Regards,
Don

Don Prince · « **Reply #4369 on:** 04 Oct , 2020, 03:42 »

Hello Mr. Tore and Simon,

Has anybody thought about a repository for all of the information in Tores Mailbox, personal documentation, with regards to the Type VII C U-Boat. The documentation that I have on my computer that went into the creation of Skizzenbuch and the coming Addendum Booklet (doc, pdf, photos, and drawings), and the many drawings that Simon has spent thousands of hours creating?

Mr. Tore started this adventure on January 12, 2012, and is in his 90s, and I will turn 80 next year, and of course I believe Simon is about half our age... However, Simon can create engineering type 3D drawing from U-Boat remains sitting on the ocean floor.

Do we have options for preserving our work for future U-Boat enthusiasts?

Kind regards,
Don_

tore · « **Reply #4370 on:** 04 Oct , 2020, 04:06 »

Don and Simon.
The coolingwater has generally a common seawaterinlet via the inlet crossoverpipe and a common outlet via the exhaustcooling headertank. Both the inlet and the outlet can be selected if need be, however normally you use a common inlet and a common outlet for both engines. As the coolingwater discharge for both engines are commonly connected by the headertank, both port and stb.systems have the same discharge head and need no checkvalve as they are hydraulically ballanced by the headertank. Ref. plate 10 below.
Tore

Don Prince · « **Reply #4371 on:** 04 Oct , 2020, 21:01 »

Hello Mr. Tore,

On sheet 10 (Fuel Oil Compensating System) that you previously posted, valve (a) shut stops high pressure in a dive from over pressurizing the internal fuel oil tanks. However on sheet 13 (Cooling Water System) I did not note a shut-off valve at the muffler side with all the different cooling water jackets and bends leading to the diesel engine; is there one? There is a shut-off hull valve on the port and starboard side taking sea water to the diesel engine water pumps.

A second question - on sheet 13, would they normally leave valve (h) open to allow both the port and starboard engines to draw cooling sea water from either hull valve. That way they could isolate either filter and replace/clean it while running both diesel engines...

Regards,
Don_

NZSnowman · « **Reply #4372 on:** 06 Oct , 2020, 15:03 »

I have worked out the alignment of the main pipe from the Muffler to the Header Tank base of a single war-time photo. The alignment is different than I previously believed.

Base on the inlet openings on the Saddle Tanks and Pressure Hull, I have a high level of certainty that these pipes entering the Saddle Tanks and Pressure Hull are around 55 mm. These are the pipes from the Header Tank to the MB & RFO Tank 2 & 4 and Engine Room.

Its also about the only way this pipe can make it to MB & RFO Tank 2, there very little space for pipes in this area (in fact I don't think I could get a 75 mm to MB & RFO Tank 2 without restructuring the deck height).

If we say these are smaller pipes entering the Saddle Tanks and Pressure Hull, do you think the main pipe from the Header Tank to the 4 way pipe connector is the same size (55 mm) or should be it be bigger at 75 mm?

Don Prince · « **Reply #4373 on:** 07 Oct , 2020, 03:15 »

Hi Simon,

Interesting... Plate 10 does indicate that the pipe from the header tank going to MB & RFO Tank 2/4 and to the pressure hull are smaller. The pipe coming from the header tank to the mufflers and the over-flow drainage pipe are larger.

The capacity from both running diesel engines water pumps would be about 96 cubic meters of cooling water per hour; Therefore I believe the larger diameter pipe from the mufflers may be required, as well as the larger diameter overflow pipe from the header tank.

Regards,
Don_

tore · « **Reply #4374 on:** 07 Oct , 2020, 08:02 »

Don and Simon.
Sorry I have been away for a few days. I guess Simons observation that the common CW pipe from the two silencer to the headertank is larger than the direct makeup lines between the headertank and silencer is correct, the overflow of the headertank must be able to handle the full coolingwater capacity of both engines. I guess the supply pipe from the headertank through the pressurehull would be 55mm diam all the way including the shutoff- and reliefvalves inside the pressurehull.
Tore

Don Prince · « **Reply #4375 on:** 09 Oct , 2020, 01:28 »

Hello Mr. Tore,

I took the drawing of the bow torpedo tube and door and added the two(2) drawings below to illustrate the outer door opening with the drawings below. What do you think?

Regards,
Don_

Don Prince · « **Reply #4376 on:** 11 Oct , 2020, 14:41 »

Hello Mr. Tore and Simon,

As you know, I have been working on an Addendum Booklet to supplement Skizzenbuch with our later discussions and any needed updates or corrections. I believe that we all have done a pretty good job with the initial Skizzenbuch, and the Addendum Booklet is currently scheduled for a release date of December 1, 2020. I have uploaded my latest version of the Addendum Booklet in dropbox, and I believe I only need to replace the image on page 47 with an update. If there is anything that I have missed, or needs to be included, then please advise...

Kind regards,
Don_

NZSnowman · « **Reply #4377 on:** 12 Oct , 2020, 13:23 »

Quote from: Don Prince on 07 Oct , 2020, 03:15

Hi Simon,

Interesting... Plate 10 does indicate that the pipe from the header tank going to MB & RFO Tank 2/4 and to the pressure hull are smaller. The pipe coming from the header tank to the mufflers and the over-flow drainage pipe are larger.

The capacity from both running diesel engines water pumps would be about 96 cubic meters of cooling water per hour; Therefore I believe the larger diameter pipe from the mufflers may be required, as well as the larger diameter overflow pipe from the header tank.

Regards,
Don_

The largest pipe I could get to fixed was 60 mm, so I will go for that.

Quote from: tore on 07 Oct , 2020, 08:02

Don and Simon.
Sorry I have been away for a few days. I guess Simons observation that the common CW pipe from the two silencer to the headertank is larger than the direct makeup lines between the headertank and silencer is correct, the overflow of the headertank must be able to handle the full coolingwater capacity of both engines. I guess the supply pipe from the headertank through the pressurehull would be 55mm diam all the way including the shutoff- and reliefvalves inside the pressurehull.
Tore

I used a online flow rate calculator and it said to match the same flow of both engine, the minimum size the pipe would need to be was 100 mm.

Don Prince · « **Reply #4378 on:** 12 Oct , 2020, 15:48 »

Hello Mr. Tore and Simon,

I attached the photo of the mufflers and the pipe to the header tank, and the bend pipes from the diesel engines. What I have noticed is the bend pipes are much smaller in diameter than the pipes to the header tank. Therefore, the flow capacity going to the mufflers is restricted to some degree, but the larger pipe size from the mufflers seems to reduce the CW pressure going to the header tank.

Remember, the 48 cubic meters of water per hour provided by each diesel engine water pump also flows towards the aft of the U-Boat to cool the thrust bearings plus other items in the aft torpedo room and exits at the aft drain port to the sea (Attached Plate 13 drawing). So, the CW pipe to the header tank doesn't need to be such a large diameter (i.e., 100 mm).

Simon, is there anything in the muffler photo that would allow you to determine the size of the bend pipes and the muffler pipes?

My Thoughts,
Don_

NZSnowman · « **Reply #4379 on:** 13 Oct , 2020, 18:08 »

Fuel Oil Compensating System

Fig. 1. Overview of Fuel Oil Compensating System (red).

Fig. 2, 3 & 4. Aft section of Fuel Oil Compensating System (red). Have not found any evidence of the true pipe alignment or the type or location of the drain valve 'e'. I have photograph evidence that indicates that the line back to the header tank runs along the starboard side of the boat. There a deck hatch just forward of the exhaust valve (orange) so I located the drain valve 'e' below this hatch.

Fig. 5, 6 & 7. Mid section of Fuel Oil Compensating System (red). Have not found any evidence that the pipe runs down the inside of the air inlet pipe but highly likely as there no room for piping on the starboard side. Have not found any evidence where the '4 way' pipe junction is located. We know where the inlets are on the saddle tanks so base on that and the deck hatches, I have located again under the hatches valve 'b'. You can also see I have located the exhaust blowing valve 'h' under the same hatch (orange).

Fig. 8 & 9. Header Tank of Fuel Oil Compensating System (red). Have not found any evidence of the layout of the header tanks but this layout seems most likely (I still need to fixs the Header Tank outlets). I found evidence the pipe running forward on the starboard side of the CT.

I need to do more research on how the piping goes around the CT, the alignment of the overflow pipe, and the alignment of the piping inside the saddle tanks to the expansion tanks.

A good start to the Fuel Oil Compensating System, I been working on this system for about four years now, so it great to see it nearing completion.

tore · « **Reply #4380 on:** 14 Oct , 2020, 00:36 »

Simon. Congratulation! Amazing piece of research and drawings, whishing we had similar drawings for instructions in my time.
Tore

Don Prince · « **Reply #4381 on:** 15 Oct , 2020, 00:50 »

Hello Mr. Tore,

I agree, Simon is a very talented young man who has researched and produced outstanding U-Boat drawings which will prove to be very accurate. I believe our teamwork with past and present members of "Tores Mailbox" has contributed to the knowledge base of the Type VII C U-Boat and we all can take pride in our work.

Regards,
Don_

Don Prince · « **Reply #4382 on:** 20 Oct , 2020, 14:04 »

Hello Mr. Tore and Simon,

I believe that I have just completed the Addendum Booklet to Skizzenbuch and I don't foresee any additional updates. Would you please review the booklet and especially check-out page 47 which is the latest entry and let me know what you all think?

I believe we have completed the Skizzenbuch: U-Boat Type VII C Project...

Regards,
Don_

Raymic1 · « **Reply #4383 on:** 12 Nov , 2020, 14:12 »

hi Don. I just PMed you.
Thanks
Mike

Don Prince · « **Reply #4384 on:** 12 Nov , 2020, 17:29 »

Hello Mr. Tore and Raymic1 (Mike),

The content (Text and images insert) on page 199 were a contribution from Mr. Tore... Mr. Tore, if you still have the photos of the hydroplane motor and clutch mechanism or any additional photos, then could you please post them here for Mike?

Regards,
Don_

Raymic1 · « **Reply #4385 on:** 15 Nov , 2020, 12:01 »

Mr Tore.
Would you have the original high resolution pictures of the Aft Hydroplane motor and clutch area that you could share?.
Mine from the Skizzenbuch are not very clear.
Thanks
Raymic Mike

Don Prince · « **Reply #4386 on:** 15 Nov , 2020, 23:02 »

Hello Mike,

I found the one image that I used to create the composition on page 199. I do not know if it is of any help...

Regards,
Don_

tore · « **Reply #4387 on:** 15 Nov , 2020, 23:53 »

Hi Mike!
I have looked into my files (which is not very impressive) and did`t find any better image than Dons. Sorry I wasn`t very organized at the time of publishing the image and in the meantime quite a few images disappeared.
Tore

Raymic1 · « **Reply #4388 on:** 16 Nov , 2020, 00:00 »

Thank you Don and Tore.
I have searched everywere on the net for these particular images with no luck. I wonder where they originated?
But Don your originals are more than good enough. I can see the extra detail that is lacking in the PDF .
Thanks again
Mike

Don Prince · « **Reply #4389 on:** 22 Nov , 2020, 00:13 »

Hello Mr. Tore,

I guess I was asleep in class, or my old age has set in... What is the function of these hand-wheels???

Regards,
Don_

tore · « **Reply #4390 on:** 22 Nov , 2020, 09:06 »

Don.
Your image shows the shut off valve in the air pipe to the starting airvalve in the cylindercover. As you remember by opening the main startingair supply you are at the same time opening for the airsupply to the top of the starting valve where a piston the is actuating the push rod engaging the roller to the camshaft, which then opens and shut the startingvalve at proper timed intervals. I guess in the official diagram they have forgotten this valve. By shutting the air valve, the pushrod roller is not engaging the roller to the camshaft and the startingair valve for the relevant cylinder is not operating.
Tore

Don Prince · « **Reply #4391 on:** 23 Nov , 2020, 15:22 »

Hello Mr. Tore,

Looking at the starting valve is the lower half in the starting valve an injector? It looks like the roller rides on a high spot on the cam, then the nozzle in the lower section of the starting valve opens.

The starting air cam roller that activates the push rod and rocker arm to inject starting air to all six cylinders. However, only one of the starting air valves at the cylinder head is open and drives the piston downward.

Am I close to correct:
1. Is there a 3rd valve in each cylinder head that is only activated (opened) while running on starting air?
2. When the 3rd valve for each cylinder is opened, starting air enters the cylinder chamber and drives the piston downward?
3. When the starting valve is not under starting air pressure, then all of the 3rd valves in the cylinder head are shut?
4. I assume the reason for the 3rd valve is to stop combustion gases from feeding back into the starting air system?

As you can see, I get lost sometime and have to find my way back... Do you have a engine drawing that shows the starting valve and the air lines to/from it, and a cross section of the starting air valve in the cylinder head?

Regards,
Don_

tore · « **Reply #4392 on:** 24 Nov , 2020, 03:18 »

Don, you are entering into a complicated system consisting of hydraulic, pneumatic and mechanical elements with a lot of interlocks if you want to include the direct reversible system of the GW dieselengine, as you know the complicated direct reversible system was omitted as from 1943 on the GW engines. On the U 995 engines you `ll find only rudiments from of the direct reversible system. As to the starting system it works as follows, each cyindercover has a separate starting valve timed and operating from a modified camshaft by rollers,cams and pusrods. The starting valve looks like on my image below and consist of a common housing with a long valvespindle having a valve in the lower end, the chamber in the valvehousing has a direct connection to the startig air supply, the valvespindle goes through the startingairspindle chamber via the lower airtight springcarrier/ guide and a shutting spring up to the upper spring carrier. The upper valvespindle ends in an adjustable connection engaged to a springloaded lever connected to a valve rod ending in a roller arm. The startingvalve rocker system is kept free from the camshaft by a spring on the valve lever keeping the rollers away from the camshaft In the starting procedure starting air is admitted to the top piston of the startingvalve spindle, forcing the startingvalverod down agains the springload and engaging the roller to the camshaft, which operate the starting valve mecanically. When the starting sequence is over, air pressure on the valve spindle toppiston is vented and the starting valve spring lever is pulling the system free from the camshaft.
Tore

Don Prince · « **Reply #4393 on:** 24 Nov , 2020, 04:34 »

Hello Mr. Tore,

Let me start to learn how the Starting Air System works on a step-by-step basis with a few basic questions each time.

Starting Air Distribution

1. Is there only one (1) Starting Air Valve on the Diesel Engine? yes/no
2. When starting air is supplied to the Starting air valve at the top, then the roller will engage the cam? yes/no
3. When starting air is supplied to the center section of the starting air valve, then starting air is supplied to all six (6) of the Cylinder head's starting air valve chambers? yes/no

Let's get an answer to these three (3) basic questions...

Regards,
Don_

tore · « **Reply #4394 on:** 24 Nov , 2020, 05:15 »

Don.
1. No.There is one starting air valve pr. cylinder e.g. 6 startingvalves for a 6 cylinder engine.
2. Yes
3. Yes, but starting air in the chamber to the cylinder is only admittet through the relevant starting valve being opened by the pushrod of the relevant cylinder.

Tore

Don Prince · « **Reply #4395 on:** 24 Nov , 2020, 12:38 »

Hello Mr. Tore,

4. Where is the starting air valve located relative to each cylinder head?
5. Do you have a photo of a starting air valve?
6. Is the shifting cam shaft one long continuous shaft to all cylinders? yes/no
7. There is only one shifting cam shaft with cams for both the push rods driving the intake and exhaust valves, and cams which drive the starting air valves? yes/no
8. Does the shifting cam shaft rotate one full revolution per two (2) revolutions of the crank shaft? yes/no

Regards,
Don_

tore · « **Reply #4396 on:** 24 Nov , 2020, 13:38 »

Don.
4.Down below is Simons image of the cylindercover where the starting valve for each cylinder is shown fitted.
5. I don`t have a photo of a separate starting airvalve.
6. The camshaft is the same as the original camshaft along the engine.
7. Hence the originalcamshaft is driven from the camshaftdrive as normal.

Tore

Don Prince · « **Reply #4397 on:** 24 Nov , 2020, 14:27 »

Hello Mr. Tore,

9. How does the starting air get to the middle connection on the inserted starting air valve which is placed into the engine valve head? I see the top connection pass air through the shut-off valve to the upper section of the starting air valve, and then it forces the roller to engage the cams...

Regards,
Don_

Don Prince · « **Reply #4398 on:** 24 Nov , 2020, 23:35 »

Hello Mr. Tore,

Thanks for the last few posts... I think that I'm beginning to understand how the starting air system works.

I added some ID tags on one of your drawings and I hope that I got it right...

10. when is the Shut-off valve used on a cylinder? Why?
11. Was that spring an added modification by crewmen (Starting valve spring.jpg attached)?

Regards,
Don

tore · « **Reply #4399 on:** 25 Nov , 2020, 01:11 »

Don.
Below is one of Simons drawings which shows the starting air supply pipe to the starting airvalves of each cylinder. As you see the startingair valve casing is protruding up over the cylinder covertop allowing space for an airchamber flangeconnection to the starting air supplypipe going along the main engine at the level of the starting airvalve connection. The shut off valve to the engaging piston on the top of the valve is clearly seen, I guess the shut off valve could be used if for some reason you would disconnect the rockerarm from the camshaft. The spring for retaining the rocker arm from the camshaft is a typical device of the prewar technology and is an intergral part of the system, not somebodys funny idea. If f.i. a starting valve for some reason stays open or start leaking, the combustion pressure in the relevant cylinder forces hot exhaust gases into the starting air system overheating the pipes. It happened to me ones upon a time and the painting on the startingpipes became so hot that the painting started to boil.

Tore