Author Topic: Tores mailbox VIIC and VIIC/41 operation and technical details  (Read 321512 times)

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Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3855 on: 10 Jul , 2018, 04:10 »
Hi Don.
I cannot state for sure how they did it in the German navy in WW2, but in my time all our submarines, including the VIICs, had annual noisetrials in a Scotish loch where the sub was semi submerged surrounded by sofisticated microphones. Each auxiliaries on silent mountings was operated separately and a complete soundgraph for the machinery (included pumps of course) was made. We knew exactly which auxilliarly we could operate.  At silent running we only operated those auxs which were within the approved silent range. This was usually the coolingwater pump in the E-room.  The trim pump (piston) we sometimes used the crew for sifting the trim as the pump sometimes could be too noisy in spite of the silent mounting.

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3856 on: 11 Jul , 2018, 07:41 »
Hello Mr. Tore and All,


I have uploaded the latest version of Skizzenbuch 11 x 17 - M + I.pdf into the Dropbox folder. Pages 33, 125, 126, 127, 128, 426, 427 have been added. However, there is no index because I am in the progress of creation a new one. Please advise if anything looks to be incorrect... This looks to be the final version except for any required corrections.


Regards,
Don_
A man’s got to know his limitations…
Harry Callahan, SFPD

Offline Raymic1

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3857 on: 11 Jul , 2018, 18:29 »
Hi Don
Just to clarify for me as I see you have all been working on this for years.
 The Skizzenbach is a book and is the dropbox file a private box for you guys whilst you are working on your project?
Also will the Skizzenbach be available later for public viewing/purchasing etc?
Thanks

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3858 on: 11 Jul , 2018, 22:18 »

Hello Raymic1,


So far "Skizzenbuch: U-Boat Type VII C Project" is my attempt to create a book that informed the reader about almost all aspects of the design, functionality,  and operation procedures of the German WWII Type VII C U-Boat. In the beginning - a few years back, I had a contract with Schiffer Publishing for the book. However, they cancelled the contract about two weeks before I was to get my author's proof copy of the book. Looking back, the cancellation was probably a good thing because I have made many changes and corrections to Skizzenbuch. I have been looking for a new publisher ever since, but with no success because most publishers say the market is too limited and the book is expensive to publish.




Skizzenbuch requires a format size of 12" x 7.75" - Landscape at a minimum, and the page count is about 510 pages including the index and at least three (3) fold-outs sheet in the back of the book. I have suggested to various publishing companies that Skizzenbuch should be a two (2) volume set. There are well over 700+ color photos and original German mechanical and electrical schematics in the book.


If I can not find a book publisher, then I may eventually go it alone... By that I mean - I could go to the expense to U.S. copyright Skizzenbuch, create an LLC publishing company and purchase the software to copy protect a downloadable file. Most likely the file will be free, and I could get books printed on demand but they would be very expensive. I am a 77 year old retired NCR Plant Maintainability & Support Engineer and Computer Hardware and Software Support Engineer with over 46 years of experience... However, I am NOT wealthy!


Kind regards,
Don_ 
« Last Edit: 12 Jul , 2018, 03:07 by Don Prince »
A man’s got to know his limitations…
Harry Callahan, SFPD

Offline Raymic1

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3859 on: 11 Jul , 2018, 22:38 »
Wow...thanks Don. That clarifies for me and I'm in awe of yours and Tores and others dedication.
In regards to complete accuracy my opinion is that given the incomplete and lost knowledge due to the loss of documents and time frame, most books already in circulation and all experts still have mistakes.
So even if mistakes are found when you release yours, the Uboat community would be very happy with any concise information and other experts would no doubt take up the challenge of continuing this as an ongoing works in progress.
And I for one would be happy to pay a fee for the PDF version if a full book was prohibitive.
I'm sure the rest of the Uboat community grateful for your efforts would also agree.

Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3860 on: 11 Jul , 2018, 23:28 »
I completely agree with Raymic...I'm sure that many U-Boat enthusiasts would be happy to pay a fee to have the PDF file and print it on their own...
Please, Don, not disperse all that material and make available, as soon as possible, the PDF file....
Filippo

Offline VIC20

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3861 on: 12 Jul , 2018, 03:40 »
You could publish it via a print on demand service.

Offline bianco64squalo

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3862 on: 12 Jul , 2018, 05:28 »
Hi Don,
in any case, in my opinion, the right thing to do is to make available the material in your possession for all U-Boat enthusiasts...
I suggest that you contact an expert in file sharing and find out a solution that safeguards your copyright and availability for interested parties too....
I'm very, very interested...
Respect.
Filippo

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3863 on: 12 Jul , 2018, 05:41 »
Don.

Skizzenbuch page 125 Schnorchel system. I guess you have been confused by two system. The VIICs schnorchel system comes in two version, the old and the later improved system. Below is my image showing the two versions. If you look at the old system it is full of bends, hence resistance, the new system elliminates the schnorchel airpipe alongside the diesel air trunk by introducing the schnorchel air straigth in to the dieselair trunk, otherwise I guess the image is shelfexplanatory.
Tore
« Last Edit: 12 Jul , 2018, 07:54 by tore »

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3864 on: 12 Jul , 2018, 10:30 »
Don

page 126
You are describing a diesel cycle calling it two cycle, four strokediesel. I guess this is a confusion as the VIICs have two four stroke supercharged medium speed dieselengines. Unless I have misunderstood you , I suggest you omit the paragraph dealing with this dieselcycle.

page 127
The dieselengine coolingwater outlet leave the engine to the exhaust bend coolingjacket, before leaving the engine, part of the coolingwater flow is manually adjusted to the correct watertemperatur read at a local thermometer to the exhaustvalve cage coolingjacket. This has nothing to do with the exhausttemperatur, only to cool the exhaustvalve cage seating to prevent burning.


As to the watercooled exhaust manifold which is having a water jacket all the way to overboard it is easy to be confused by the numerous venting and drainingpipes of the cooling waterjackets, non of them are used for draining a flooded exhaust manifold. At the bottom in the aft end of the exhaustmanifold is a drain pipe to the bilge this is the only drainpipe to the inside of the manifold used for draining a flooded manifold. This drain pipe is unfortunately not shown on plate 13. The drain of the inside of the group exhaustvalve is shown on plate 13.
Tore
« Last Edit: 12 Jul , 2018, 10:41 by tore »

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3865 on: 12 Jul , 2018, 12:39 »
Don.
May be it gives a better understanding to see a crossection of a typical watercooled exhaustvalve cage.

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3866 on: 12 Jul , 2018, 21:45 »
Hello Mr. Tore,


Page 125 - My intent on that page was to show the huge size of the diesel air intake trunk (dark blue in Simon's drawing). Then to compare the smaller schnorchel air feed line attachment to the diesel air intake trunk. The schnorchel head air intake feeds air through the mast to a bend (newer design) or a pipe on the port side of the forward bridge (older design). Either way, the air intake from the schnorchel mast is limited in volume as compared to when running on the surface and taking air via the diesel air trunk. In addition, the compartmental air intake and exhaust stacks are shut when the schnorchel is in use; further limiting the air supply to the U-Boat.


Therefore, the air resource is limited when the schnorchel is in use...


Should I add some of the above comments to clarify and to better understand page 125?


Regards,
Don_
A man’s got to know his limitations…
Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3867 on: 13 Jul , 2018, 00:42 »
Don.
You are right in stating the major air restriction is in the float air intakevalve and the schnorchelmast, however the new system improvement was connecting the smaller schnorchel air pipe to the diesel air trunk close to the diesel air main intake valve thus eliminating the long narrow schnorchel airpipe all the way to the main inlet valve in the engineroom. The sketch might be a bit misleading with regard to the new system as it does not show very clearly the airpipe from the schnorchel mast is entering the large dieselair trunk close to the dieselair main inletvalve thereby utilizing the dieselair trunk also for possible waterintrusion. I am enclosing a revised image below. When schnorcheling you had, as you state, a limiting factor as to the speed and load of the engine. Speed because of the strength of the mast, dieselload (generator load)  because of the airconsumption. The control was monitored by the barometic pressure in the compartments, the pressure fluctuation you could feel in your airdrums.

Offline Don Prince

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3868 on: 13 Jul , 2018, 01:20 »
Hello Mr. Tore,


As stated by U-480's captain, they had to use many CO2 canisters while schnorchelling (I guess they were under water more than on the surface). In that situation, I would assume they had to run both ventilation blowers. Did you experience the large use of CO2 canisters while onboard of U-995?


Regards,
Don_
A man’s got to know his limitations…
Harry Callahan, SFPD

Offline tore

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Re: Tores mailbox VIIC and VIIC/41 operation and technical details
« Reply #3869 on: 13 Jul , 2018, 02:00 »

Don
We did not use any CO2 cannisters while schnorcheling, in fact generally the air quality improved as the diesels consumed the very quickly the fouled air. The problem were more individually some could not take the pressure fluctations, a few even experienced a bursted eardrum. Another experience was people with bad toothfillings experienced overpressure under the fillings creating some pain.
Tore