Type VII - Schnorchel Placement

[NZSnowman]

Hi NZSnowman
I`m amaized with your drawingskill. It migth be somewhat confusing to some with all the smaller piping around the main exhaust outlet. As you probably know part of it is due to the airdriven gindingmachine connected to the exhaustvalvedisk via a gearpinion to a gearrim on the disk.  At every dive one of the engineers had to start the grinder and rotate the disk to remove the carbondeposit on the seating. If the valve was leaking the trick was to wait till the we got 2-4 meters waterpressure on the disk. At periscope depth the pressure was to high for the grinder. An unpopular sideeffect of the airdrive was in the event of a bad leaking valve you build up an overpressure in the sub.
Regards Tore

I read somewhere that the Germans would do this every 3 hours while running the diesels. First they would stop one diesel and clear the seating, then restart this diesel, 3 hours later they would stop the other diesel and do the same.
 
This part of the drawing it not up to the standard I would like, the drawing very basic. Very limit detail and information around on the piping structure of this area of the boat. I base most of my drawing from a picture of U-250.

[NZSnowman]

Drawings, manuals.
Hi Maciek!
Good question. The story is. I was taken rigth from my graduation at the naval academy and sent to the Royal Navys submarine trainingcenter HMS Dolphin at Gosport near Portsmouth. Attended an Engineering Officers trainingcourse learning practically evrything about the RN`s  A, T, S and U/V class submarines only to return to Norway and to my astonishment realized I was assigned a VIIC of which I did`t know much. The design difference of the two countries submarines was significant. In 1953 we did not have any connection with the germans and the documents/manuals were were not overwhelming. Thus you had to do it the hard way, trying and failing. Some of the failings were exciting. Eventually we become pretty good in handling the boats I dare say.
Regards Tore

I bet some of the failings were exciting and were events that you wish would not happen again I remember reading some funny stories while training the German crews to sail the U-boats. I can only imagine you had fun!
 
I think I would almost give my right arm to see so of them drawings and manuals now. Tore, do you think the RNoN would still have them?

[tore]

Exhaustvalve grinder
Hi NZSnowman!
I have to admit I couldn`t quite follow the piping on your drawing. I believe the details are clearly visible on the U 995 at Laboe, the system should be still intact. May be somebody could can take a picture for you. To me grinding every 3 hours seems to be excessive, migth be they had a low fuelquality. On the other hand a leaky main exhaustvalve could be serious, in spite of the drains, we flooded the cylinders more than once and your correct drawn indicatorcocks were as a standard procedure always open while turning the engine prior to the starting after surfacing. It happened water did squirt out of the cocks and a waterstroke risk was a nigthmare. A few times we had to surface due to a leaking valve. So this was an important item.
Regards Tore

[tore]

Manuals and drawings.
Hi again NZ Snowman!
I guess some manuals are still at the Norwegian Naval Museum in Horten, Norway E-mail: mar-mus@online.no but I am afraid they are all in norwegian.
regards Tore

[TopherVIIC]

Manuals and drawings.
Hi again NZ Snowman!
I guess some manuals are still at the Norwegian Naval Museum in Horten, Norway E-mail: mar-mus@online.no but I am afraid they are all in norwegian.
regards Tore

Hi Tore! Love having you here!
Do you think they would entertain requests for information from New York, USA? I am sure we could slug out the Norwegian, but this group is pretty good at deciphering such things!
Cheers
Christopher

[NZSnowman]

Hi Maciek!
Trying to post a picture of KNM Kaura`s snortmast half raized. the young handsome man with white cap inspecting it is me!
regards Tore

Hi Tore

I was wondering can you remember the colour of the very top on the schnorkel head?

I have always wondered that colour the Jaumann-type anti-radar coating was. Most photographs show it as very dark, perhaps black or very dark gray (even in your photograph is look very dark) however, I have one photograph of U-325 schnorkel head and it look gray and perhaps painted in a camouflage pattern

[tore]

Manuals Drawings
Hi Christopher!
I just realised you are building an unbelievable VIIC/41 model and hence thirsty for details which are far beyond my capacities allthough I spent hours crawling around in the narrow spaces. I wish I had kept my numerous sketches now for your museumpiece. I donated all my sketchbooks to the Norwegian Naval Museum, unfortunately they were only dealing with RN`s  A,T and S class thus of no use for you, however the RNorN submarineservice, www.uvb.no, had a designoffice for possible conversion of our older british and german subs and it migth be they have some detailed drawings.
I all modesty I`m in the final stage of a 1/72 model of KNM Kaura, the norwegian version of VIIC/41 (ex U 995) this how the real boat looked like in my time. 
Regards Tore

[tore]

Hi Maciek!
Trying to post a picture of KNM Kaura`s snortmast half raized. the young handsome man with white cap inspecting it is me!
regards Tore

Hi Tore

I was wondering can you remember the colour of the very top on the schnorkel head?

I have always wondered that colour the Jaumann-type anti-radar coating was. Most photographs show it as very dark, perhaps black or very dark gray (even in your photograph is look very dark) however, I have one photograph of U-325 schnorkel head and it look gray and perhaps painted in a camouflage pattern

Hi NZSnowman
As I remember it was black at the time I was onboard, however we did tried out different colours and and as I remember a kind of greenish/dark blue turned out to be the best. We never repainted in my time. I guess it was more the size (radarreflection) and wake than the colour which betrayed the snorthead.

regards Tore

[tore]

Hi again NZSnowman
Just reading my quick answer to you I realised it`s a bit on the side. Non of the our electro/pneumatic snortheads had the Jaumann type of covering, it was simply a small "steelbarrel". I guess this was just the time when it was more important to register that you was detected than trusting you wouldn`t be. That the device possibly could act as a "ligthouse" was another question.
Regards Tore

[TopherVIIC]

Hey Simon - Unless I am wrong, this picture of U-1065 (VIIC/41) has your ductwork for the snort.
http://img20.imageshack.us/img20/5418/u1165.jpg


Right in this very thread is u249londonderry570zn7.gif with what looks to be the same ductwork. Am I seeing that correctly?
Christopher

[TopherVIIC]

I all modesty I`m in the final stage of a 1/72 model of KNM Kaura, the norwegian version of VIIC/41 (ex U 995) this how the real boat looked like in my time. 
Regards Tore

Tore,
Thanks for the Pic of the KNM Kaura, and your stories of  your experiences with her. Thank you also for your good thoughts about my build. I am sure the folks here would enjoy seeing your build also!

thirsty for details which are far beyond my capacities allthough I spent hours crawling around in the narrow spaces. I wish I had kept my numerous sketches now for your museumpiece.

If I were closer to Labeau I would crawl all over her too, with camera and sketch pad in hand! :-)

Stay well.
Christopher

[NZSnowman]

Hi again NZSnowman
Just reading my quick answer to you I realised it`s a bit on the side. Non of the our electro/pneumatic snortheads had the Jaumann type of covering, it was simply a small "steelbarrel". I guess this was just the time when it was more important to register that you was detected than trusting you wouldn`t be. That the device possibly could act as a "ligthouse" was another question.
Regards Tore

Hi Tore
 
From my research on the Schnorchel I believe that KNM Kaura did have a Jaumann-type anti-radar coating. The Jaumann-type anti-radar coating was about 70 mm in thickness. As it was coated on both side of the head this added additional 140 mm to the diameter to head. The German

[Rokket]

Tore - keep us posted on your build, excellent subject. I love the "different" projects myself, something that is unique or has a twist. A Norwegian version in those lovely fjords...Ja!

[tore]

Hi again NZSnowman
Just reading my quick answer to you I realised it`s a bit on the side. Non of the our electro/pneumatic snortheads had the Jaumann type of covering, it was simply a small "steelbarrel". I guess this was just the time when it was more important to register that you was detected than trusting you wouldn`t be. That the device possibly could act as a "ligthouse" was another question.
Regards Tore

Hi Tore
 
From my research on the Schnorchel I believe that KNM Kaura did have a Jaumann-type anti-radar coating. The Jaumann-type anti-radar coating was about 70 mm in thickness. As it was coated on both side of the head this added additional 140 mm to the diameter to head. The German’s only used the costing on the very top of the Schnorchel.
 
From the drawings below you can see the different between the Schnorchel head with the costings. You can see the drawing on the left has the bigger diameter to the head. This is the additional 140 mm of the Jaumann covering. You can see the original diameter of the pipe below the Jaumann.
 
From your picture (69.gif) we can clearly see the same profile, the small diameter lower pipe, and the larger diameter top half.
 

Hi NZ Snowman!
You are absolutely right. I guess I got confused and took the Wesch type antiradarcoating for beeing the Jauman, honestly we were not so familiar with the german names and moreover we never were concerned about the thing. Anyhow it was black. In those days (the early cold war periode) the average radar was not that great. We tested our german radar a foggy day outside the Lofoten islands northern Norway and got no echo on the screen, then we blew the whistle and got immediately an soundecho and when the fog disapeared we looked at a mountaindropoff of 4-500 m  high  rigth in front of us. Due to this experience we never used the radar but trusted only the sonar and hydrophones.  I`m impressed by your knowledge.
Regards Tore

[tore]

Hi Rokket !
Thanks for your interest in an old mans activities. My modest model of KNM Kaura is partly based on the Revell VIIC/41 1/72 atlantic version type, with some modefications, (the U 995 at Laboe is not a very good reference, particulary on the casing and floodgates). I had primarely to change the conningtower (I had to cast a new afterpart),the snort and snort lockingpin details, furthermore the casing and wooden deck including the snort casing and pressurecontainers. I`m now busy with the challenging task for an old mans stiff fingers to get the rigging correct and hope to be ready within a couple of weeks. If of any interest I`ll see if I can manage to make a picture (my camera gave up, new camera).
Regards
Tore