Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Don.
Indeed, so I had to check the list once more and found that U-318 is missing. In addition to this list the convoys included Grille, Hitlers former yacht, Huscarean a submarine depot ship,  Kamerun a minelayer, Stella Polaris an ex. Norwegian passengervessel and a naval tanker Kaernten. Only the Uboats continued to Loch Eriboll, the other ships continued to Trondheim. U315 CO. Zoller and U 318 CO. Will wanted to go on fighting instead of obeying order from Captain U/B northern waters, Reinhard Suhren. However upon a repeated order from Suhren they gave up.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,


Mr. Tore - thanks for the additional information.  I have 2 paragraph on page 437 concerning 'After Germany's Surrender" I added stuff like full names and rank.  I hope I didn't get it messed up...


Maciek - thanks for the email and links to the RADAR information.  I read through everything and I believe I got it better,  I made some assumptions on my own as to the location of the receiver modules.  The RADAR pages are 434 - 435.  I hope I'm not way off base...


However, if I am wrong.  Will you all please let me know...  I uploaded the latest version of Skizzenbuch to dropbox.


Regards,
Don_

[tore]

Don.
Just a small correction to your last "Skizzenbuch". In addition to U 315 the U-318 CO. Josef Will was in for continue fighting in the beginning.
Tore.

[SnakeDoc]

Hi Tore,

during some researches I have found information, that U663, before leaving Bergen for her first war patrol, had a collision with something called Felsen. I guess, that it was either ship or underwater rock or shoal. Do you know something having this name near Bergen?

--
Thanks, regards
Maciek

[tore]

Maciek.
To my knowledge there are no area or place in Norway called Felsen, neither is it a Norwegian name. However in the Bergen area there are many places which the Germans would name Felsen, so I guess it could be any place on the Norwegian coast.
Today 9. April  we are commemorating 75 years since the German invasion of Norway. Prior to the invasion the famous Polish submarine Orzel operating  in the RN 2nd. submarine flotilla outside the Norwegian coast, sank  April 8. the German troop ship Rio de Janeiro disguised as a cargoship hiding the invasion equipment and troops in the cargohold. As the soldiers were rescued by the Norwegians they told their story but nobody would believed  what they told. That very night to April 9. the invasion came.
Tore

[Don Prince]

Hello Mr.Tore,


U-318 was not in the list of 15 U-Boats...  Do I need to add another U-Boat to the lost or correct a name?


Regards,
Don_

[tore]

Don.
 U 318 was the missing 15 th. Uboat to be added to the list. See my post April 8th. the list is corrected by U 318. The fact is that on May 8th. it was 12 U boats in Narvik, 3 of the last Uboats came in May 9 th. namely U 278, U 318 and U-992. making a total of 15.
Tore

[falo]

Hello Tore,


me again with another technical question   


Please take a look at the attached pictures, showing the vents near by the kiel of the typeseven. Years ago I read somewhere that the vents were always open (as shown on the kit pictures) no matter if the boat was submerged or operating on the surface. I wonder if this information is correct? Many modelers of the typeseven kits are showing the vents closed, are they wrong?


Thanks in advance
falo


P.S.:
I caught the attached pictures a view years ago from this thread, started by member "Jan" in 2008:
http://models.rokket.biz/index.php?topic=68.0
Today sad to say the pictures of this thread are inactive.

[tore]

Falo.
The Kingstons,(Flutklappen) were shut when you  was alongside for some time f. inst refitting/ repairs. We kept the Kingstons shut when f.inst we expected unauthorised people on board, like a coctail party. It could happen somebody felt like removing the locking pin and pulled one of the ventlever of the main ballast tanks. On my model I made separate Kingston in an open position, see image below.
Tore
 

[falo]

Hi Tore,

thank you very much for you fast reply and the attached picture (by the way great looking model).

So if I understand your answer right you operated with opened "Flutklappen"/Kingstons during operations (I mean far away from harbour or yard) no matter if dived or surfaced? Resp. the opened Kingstons were standard during patrols?

Sorry for asking again.

Regards
falo

P.S.: Hence the Eduard photo etchings (1/72 scale) for there Kingstons are not correct because they offer a grid solution (?)

[tore]

Falo.
 Open Kingstons was normal standard during patrol. Normally open all the time when submerged, may be pending circumstances in wartime, shutting the MBT 3 Kingstons during depthcharging. The gratings for the MBT 3 Kingstons on the Edward photo etchings is possibly based on a misunderstanding, assuming as the       " flutklappen" for the Qs have gratings, seen aft of the Kingstons for the saddleballast tanks 4 port and stb., the same would occur for MBT 3 Kingstons.
When I was on board and still a skinny guy I managed to crawl into MBT3 through the Kingstons and did not hit any gratings.
Tore

[falo]

Hi Tore,


thanks again, your professional knowledge is striking.


Regards
Falo

[SG]

Tore, how many Kingstons (outwards opening) per side on a VIIB?
Thanks in advance

[tore]

SG
I believe the VIIB had 4 Kingstons on each side.
Tore

[SG]

Thanks a lot, Tore!

[Don Prince]

Hello Mr. Tore,


The original list with 14 U-Boats was:


"The formidable fleet of 15 U-Boats, U-294, -295, -312, -313, -363, -427, -481, -668, -716, -968, -997, -1165, -278, and -992 sailed on May 16th 1945 southwards bound."


Then your answer was:


"Indeed, so I had to check the list once more and found that U-318 is missing. In addition to this list the convoys included Grille, Hitlers former yacht, Huscarean a submarine depot ship,  Kamerun a minelayer, Stella Polaris an ex. Norwegian passengervessel and a naval tanker Kaernten. Only the Uboats continued to Loch Eriboll, the other ships continued to Trondheim. U315 CO. Zoller and U 318 CO. Will wanted to go on fighting instead of obeying order from Captain U/B northern waters, Reinhard Suhren. However upon a repeated order from Suhren they gave up. "


In the original list of 14 U-Boats, neither U-315 Zoller's U-Boat or U-318 Will's U-Boat is included.  That's my point of confusion.  If I add U-315, and U-318 to the list, then my list has 16 U-Boats.


Regards,
Don_

[tore]

Don.
U 315 was not amongst the Uboats in Narvik she was already in Trondheim unfit for sea,but the CO. Zoller wanted to continue fighting, my mistake, so we leave him out. The fact is: on May 8th. 1945 following Uboats were in port at Narvik : U-294, U 295, U-312, U-313, U-363, U- 427,  U- 481, U-668, U-716, U 968, U-997 and U-1165, being 12. In the morning May 9th. following Uboats arrived: U 278, U-318 and U-992 making a total of 15. Of these 15,  CO Will on U 318 wanted to continue fighting, but was ordered by Captain Suhrer to surrender and thus the convoy of the 15 uboats mentioned above plus the previously mentioned vessels sailed from Narvik May 16th. bound for Trondheim, but the U-boats were later redirected to Loch Eriboll, Scotland, the other vessels continued to Trondheim. U 315 and Zoller remained in Trondheim. I hope we got it right by now.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,


I updated Skizzenbuch with RADAR and GSR info and I corrected the info about the relocation of 15 U-Boats at the end of WWII.  While searching the internet, I found that I did NOT have a correct photo of Buchheim, or the correct information...WOW what a screw up that would have been!  I believe I have the correct info and photo.  The younger Buchheim does resemble the older Buchheim...


I uploaded the latest version of Skizzenbuch to dropbox, all 457 pages...


Regards,
Don_

[tore]

Don.
As far as the 15 uboats concerns your corrections seems OK.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,


I received an email this morning from Schiffer Publishing stating that they will be sending me a contract for:


"Skizzenbuch: Type VII C U-Boat Design and Functionality"


This afternoon my stomach still has "Butterflies" form the news.  I guess I was always expecting a rejection and this has not set in as of yet.  However, I have you and Maciek to thank for all your help with the book, and I will ask another favor.  Please take a close look at Skizzenbuch and if anything looks wrong or questionable, then please advise me of such.


Kind Regards,
Don_

[Don Prince]

Hello Mr. Tore and Maciek,


I just finished updating the GSR pages in Skizzenbuch and uploaded something like the Final version pending corrections to dropbox for your approval...


Regards,
Don_

[tore]

Don.
Congratulation!
 As the book contains today 457 pages it would take some time to check the whole book and may be the publisher would have a saying as well. I shall revert as time permits with possible remarks as I start checking the details whithin my knowledge.
Tore
 

[tore]

Hydroplanes.
The most common visible mistakes made by modelbuilders can be noticed on the hydroplanes, as the building kits as well as many GA drawings contains the same mistakes. On most of the GA drawings the hydroplane shafts are indicated as a shaft centerline going through the hydroplane guard as an outer support for the plane. The plane is made of welded steelplating filled with impregnated wood and the plane shaft ends about half way into the planes where a fixing nut is situated. The access is via a small bolted cover. On the aft hydroplanes it is a shut connection between the guard and the plane by a small stubshaft which has a small nut outside the guard, this is not a support, but a guard to prevent ropes or wires to come in between the plane and guard. Once we had an incident up north of Scotland during a night anchoring near Scapa Flow. When rising the anchor in the morning we discovered that the anchorchain had stuck between the guard and the forward hydroplane. No 1 had to dive in the cold water using his longjohns as wetsuit to release the chain. On that occasion it would have been handy to have a shut opening between the guard and the forward hydroplanes as well.

[tore]

Don.
Skizzenbuch. I have read the page 1-31 of the buch and recommend to change on page 31 last sentence on the main drainpump starting with " when draining from the forward  and aft.... by the following:  "The pump has a capacity of 1300 l/ min against up to 15 meters head in parallel, single stage mode and up to 500 l/min against a head of up to 100m in series, two stage mode." You can of course maintain the pretty obvious comments on the suction resistance, which in addition to the pipelength is depending upon the valves and filters in the system.
Tore   

[SG]

Tore, thats a great clarification! I had always thought that there was a connection between the forward hydroplanes and their guards.
Outstanding, Tore, as usual!

PS. warm blankets and a hot cup of joe for n.1 after his exploit in the freezing water? 

[tore]

Tore, that's a great clarification! I had always thought that there was a connection between the forward hydroplanes and their guards.
Outstanding, Tore, as usual!

PS. warm blankets and a hot cup of Joe for n.1 after his exploit in the freezing water? 

SG
When at anchor, not leaving before the next morning the Officers were allowed one Anchor dram, a whisky shot, pro man and that`s what he got ( the  night before). I am afraid we did`t have any extra blankets so he had to use his bunkblankets.
Tore

[SG]

 

[Don Prince]

Hello Mr. Tore,


I will make the changes to page 31 (already done so just waiting before redoing the complete PDF file)...


Thanks.


With regards to the model's forward hydroplane; my OTW Type VIIC U-Boat Kit (about $1,100 fiberglass and brass 1/32 scale) has a solid brass leading faring with two heavy brass studs that extend through the fiberglass hull.  I threaded the brass studs and bolted the fairings to the fiberglass hull.  The fairings don't have the incorrect end nuts.  However, there a small stud that extends into the outside of the forward hydroplane, but that is not visible.  So I guess OTW got it right...


Regards,
Don_

[tore]

Don.
Skizzenbuch page 39-46.
I have read through these pages and can`t find anything wrong but still I am afraid that the readers might have difficulties to understand the system. On page 39 you introduce the Q system by quoting the translation of the German Divingregulation. I am afraid the document has a fraction of "google translation" as might happen when the translator do not fully understand what the text describes. Furthermore these instructions are general and concerns a number of different types of U-boats.
A simpler text for the readers could be, after giving a short description of the Q (Untertriebzelle) system:


   Crash dive procedure.
 Preparing for crashdive implies filling the Q by opening the Q- floodvalves at the bottom of the tanks and the inside Q-ventvalve venting the tank through the mufflers in the control room. The boat is now floating heavy on the ballasttanks. When crash dive orders are given the boat is heavier than normal and dive quicker through the surface. Experience shows penetrating the surface is the crucial time delaying factor. As soon as the boat is submerged the normal trim , speed and hydroplanes controls the descend effectively and the Q has a smaller effect. Thus the Q is blown immediately  after boat is submerged 8-10 meter, saving HP air. Blowing is done by shutting the inboard Q-ventvalve,  now the common Q-ventpipe can be used as Q- blowing pipe and air via the common Q- HP blowingvalve is admitted to the pipe and in to the Q-tanks forcing water out of the bottom Q-floodvalves. The Q tanks are pressureproof for external pressure by internal strengthening, but have limitation as to internal pressure not exceeding 2 kg/cm2 above the ambient external pressure hence the Q system has differential gauges which are to be monitored to keep the inside tankpressure max.2 kg/cm2 above the prevailing external seapressure.
The waterlevel inside the Q tanks are monitored by testcocks. When air is coming out of the lower testpipe the Q floodvalves are shut and blowing is stopped. When the boat ascend the pressure differential gauges are monitored and possible overpressure is released into the boat.

The essentials of the above is repeated in different wording on page 39 through 44. which might be confusing. The artificial use of "express" would be confusing as well, as in RN English we use blow Q and vent Q.
Have a look at it with the eyes of a non expert reader and see if it is worth while changing.
Tore

[SnakeDoc]

Hi Tore,

The artificial use of "express" would be confusing as well, as in RN English we use blow Q and vent Q.

Well, I suppose, that term "express" was used to indicate that Germans used different terms related with blowing:
- anblasen - blowing tanks with compressed air
- ausblasen - blowing tanks with exhaust gases
- ausdrucken - blowing negative tanks
It can easily make confusion, as in RN English (or US Navy English) there are no equivalents of these terms.

I agree with you, that in such case, the quotation from the "Diving regulations" should be replaced with reworded description.

--
Regards
Maciek

[Don Prince]

Hello Mr. Tore and Maciek,


I really learned a lot form the discussion about page 39...  I updated page 31 as per Mr. Tore's previous recommendation.  I swapped page 38 and page 39 for cosmetic reasons, and updated page 38 to reflect the discussion which I found to be fascinating!  Please advise if you all approve of the new page 38.


I placed the latest version of Skizzenbuch into dropbox...


Regards,
Don_

[tore]

Don.
Your update seems to be OK. A small remark. On page 42 you have a cross section drawing of the Q tank, referring to the drawing at right, the drawing is to the left.
Tore

[tore]

Don.
Regulating tanks.
The description used by quoting the translation of the German divingmanual resembles what we previously have discussed under Q tanks nothing particularly wrong but difficult to understand for the readers speaking English.
I have made another attempt to describe the regulating tank system as follows:
The regulating tanks are provided for compensating the submarines daily change of weight and buoyancy due to consumption, leakages, seawaterconditions (salinity and temperature) and displacement changes with regards to compression of the pressurehull during deep diving.
There are four regulating saddletanks, two ( reg. tanks 2 port and starboard) each having a capacity of 7.600 m3 and two (reg. and f.oil. tks no 1 port and stb.) each having a capacity of 4.700m3. The latter tanks can be used as reserve fueloil tanks.
All the tanks are made pressureproof having a testpressure of 14 kg/cm2. If the differential pressure between two adjacent tanks exceeds 14 kg/cm2 f. inst in the  reg. tank 2 between Q and reg./ fuel oiltank 1 the two latter tanks should be put under some pressure to avoid exceeding the max. differential pressure and rupture of the bulkhead between the tanks.
All the tanks have graded waterlevel gauges in the controlroom showing the prevailing watercontents. All tanks can be operated by the main drainage pump, aux trim and drainage pump as well as airpressure.
When diving a pair of regulatingtanks are made ready for flooding and shallow water  discharging by air. The other tanks connected to the main drainage pump in two stage configuration ready for for discharging at greater depths and the tanks are put under airpressure app. 10-12 kg/cm2.
When cruising at periscope depth a decreasing of weight is done by admitting pressure air to the tank in shallow water configuration pushing the water out of the tank thus avoiding to use the main drainage pump set to deep discharging of the deepdiving regulating tanks.
An increasing in weight is done by filling the tanks via the fine filling seavalve and flowmeter.

When going deeper the pressurehull is compressed and the displacement is becoming smaller hence the buoyancy is less. This has to be compensated by discharging water from the regulating tank in deep dive mode. The required capacity would be appr. 100l/10m, but usually more is discharged to compensate for leakages.
Plate 7 shows the regulating tank system, however the real system deviates somewhat from plate 7.
Below I have tried to sketch an image to show how I assume the system works.
The fuel/regulating tank 1 port and stb. (red) are selected as the flooding/ discharging shallow water tanks. Flooding is done via the fine flood seavalve and meter, the discharge is done by admitting air pressure to the tanks (red pipelines), forcing the water either through the normal sea valve or the seavalve to MBT 3.
The regulating tanks no 2 port and stb. (yellow) are in deep water configuration having the main drainagepump impellers in series and the tank airpressure up to 14 kg/cm2. Discharge pipe (yellow) directly via the normal overboard valve or via MBT 3.
The above suggestion is one of several possible configuration indicating the working of the system. I have left out the fuelconfiguration of the regulating/ fueloil tanks for simplification.

[Don Prince]

Hello Mr. Tore,

"the discharge is done by admitting air pressure to the tanks (red pipelines), forcing the water either through the normal sea valve or the sea valve to MBT 3."

I  believe this should be the "(GREEN Piplines)"


I have done as you suggested and added 2 pages to Skizzenbuch to include your excellent drawing and description.  I re-indexed the book and re-numbered the 3 MS Word sections and re-compiled them into one PDF.  I have loaded the latest version of Skizzenbuch into dropbox...


Regards,
Don_

[tore]

Don.
Somehow the word pipelines was added after the red. It was meant to be red, referring to the tank, if referring to the air/vent it should of course be green.  If you look closer to the system you`ll see it resembles the Q system, using the same pipeline for "blowing" (admitting air) and venting, may be you could add that in the text.
Tore

[tore]

Don.
On page 38 you have a definition of the 3 different blowing orders used by the Germans. Your definition of 3. "Ausdrucken" is blowing the negative tanks. I don`t think this is quite correct as it is more general and concerns other tanks as well. If you look at plate 7 you shall see an airpipe into the common vent/blowpipe for the regulating tanks 1 and 2 marked "Ausdruck leitung". In this connection I believe it is meant an air pipe to put the tanks under pressure. This might be for transfer of water, as well a compensating for pressure differentials. An order in RN English for that would be: Pressurize tank no... to ... kg/CM2. My revised plate 7 sketch has a minor mistake as the " Ausdruck" airpipe for port regulating tanks did not have the blue colour as corrected on the revised sketch below.
Tore

[tore]

Don.
Minor correction page 44 left photo reliefvalve. Page 46 pressure differential manometer, gauge written gage, may be you can skip the gauge. Same thing in the last sentence down the page.
Tore

[Don Prince]

Hello Mr. Tore,

Great find of the wrong spelling of "Relief."  That would have been caught with spell checker because it was embedded in a photo.  I had gauge wrong in many places and fixed it with a search and replace...

I used your latest drawing and worked on the definition issue...  a strange thing; my internet translator does the following:

ausdruck = expression
ausdrucker = print out

That certainly is confusing!

I uploaded the latest version of Skizzenbuch to dropbox...

Regards,
Don_

[tore]

Don.
Your latest correction seems to be OK to me as long as you take the blame for my text you are using the word I.
Language can sometimes be difficult particularly when selecting words in a complicated technical description as you have to know the subject fairy well to choose the right words. The difference between submarine anblasen, ausdrucken and ausblasen is a bit complicated no wonder you are confused when you dictionary tell you ausdrucker means print out.
Tore

[Don Prince]

Hello Mr. Tore,


That was a type-O it was ausdruchen (print out)... The translation site uses 4 different translators in its presentation (Microsoft, Google, Babalon, and Prompt-Online).


http://imtranslator.net/compare/german/to-english/translation/


Regards,
Don_

[Don Prince]

Hello Mr. Tore,

In order to eliminate any possibility of confusing the reader of Skizzenbuch, I took your suggestion and updated pages 38 through 46.  I uploaded the latest version of Skizzenbuch to dropbox.

Please advise if I got anything backwards, or used the wrong context...

Regards,
Don_

[tore]

Don.
You update seems OK. to me, just a small misprint i qouting my remarks on page 38..... " as soon as the U-boat is submerged at normal trim, speed and the hydroplanes control the decent effectively.... I wrote descent but I hope the control goes decent as well .
Tore

[Don Prince]

Hello Mr. Tore,

Just for my own info....

I have a question about the regulating tanks set-up as a shallow dive tank.  When you want to decrease the contents of the tank, in this case you use air pressure to discharge some water into the sea, or MBT 3. Do you bypass the Main bilge pump with the two valve chests, or do you use the pump?

Regards,
Don_

[Don Prince]

Hello Mr. Tore,

I corrected the spelling of "descent" on page 38, and added some context to page 47.  I uploaded the latest version of Skizzenbuch to Dropbox...

Regards,
Don_

[tore]

Don.
You  normally don`t discharge the water by air through the main bilgepump pump.  In this case I guess I would discharge to the main valvechest and to the sea valve ,
However if the relevant tank is the reg and fueloil tank no 1 recently used as fueltank I would discharge into MBT 3. Just to give an indication of the many aspects and alternatives you have, I guess there is no single right answer for all conditions. You can compare a VIIC with an instrument well designed and the men that plays her as musicians. There are many ways to get the best out of her, depending upon the skill of the players, a manual cannot cope with all the variables and as such tell you what to do. The standard of the boat is set by the knowledge, skill and experience of the crew.
Tore

[tore]

Transferring liquids in a confined space is in some cases difficult to understand.
May be the trim system used for compensating for weight shifting fore and aft gives an explanation.
The image of the system is shown below. One trimtank is situated forward and one aft, an approximate distance between the tanks of some 41,6 meters gives a proper correctional momentum by shifting a relatively small amount of water in the system. The water can be transferred either by the trimpump or airpressure. When the system is operated by the trimpump, water is pumped through the trimline. The volume of the shifting air and water in the confined system is constant (you don`t add air or water to the  system) and according to plate 6 you don`t have local venting, everything is centralized in the controlroom. However as the volume of  water is shifted, the air volum ("venting") has to be shifted as well. This can be done by the airpipe between the tanks by putting the blow/ venting cock in the pumping position, straight through the cock as indicated on my image below, allowing the air to move between the tanks. Thus by pumping water from one tank to the other the ventingair can be shifted to the opposite tank via the airpipe. 
   When  trimming by airpressure the valves to and from the trimpump are shut, the water distributing ( Schalter) valve is put in a middle position and you have a direct water connection  between the two tanks, shortcutting the trimpump. When selecting the tank for air pressurizing (blowing) you put the air / venting cock in the airpipe in the required position and as you pressurize one tank by the air blow valve,  you vent the other. As you admit air to the system the tanks have to be vented into the boat, which means increasing the inside pressure of the pressure hull.
We usually used the trimpump avoiding increasing the ambient air pressure in the boat.
 The above is just an example to illustrate the physics of moving liquids and air in a confined space like a submarine.


Tore

[Don Prince]

Hello Mr. Tore,

I added some info to the compensation section and uploaded the latest version of Skizzenbuch to dropbox.

Regards,
Don_

[tore]

Don.
I think you put the description of the two ways of trimming just on the right place.
 When you see the VIIC system like the trim arrangement photo in the controlroom, having all the rough essentials in one place for trimming, it strikes me we did not badder to have a special place for the trimoperator who should handle the system. In to days submarines I guess the same system is installed, however the operator is probably sitting in a proper designed chair, looking at a screen, pushing coloured buttons for the same functions (and even more) as we turned the valves and cocks standing, stretching and twisting around using our ears, noses and eyes to monitor the operation. It calls for some reflections, today you put in  extra technical elements between the human operator and the piece of equipment we are controlling, are we loosing our the ability to use our senses by introducing  extra elements which might have a potential of failures? The VIICs are one of the last advanced mechanical, directly controlled submarines which made it unique though cumbersome to operate and maintain, thus having the disadvantage of requiring a large crew. To days submarines of the same size would probably have a crew of less than half of the VIICs and still a larger striking power.
Tore

[tore]

Don.
Referring to page 78 having showing an image of the fueloil watercompensating system plate 10 you have a description of same underneath starting with "when the U- Boat submerges.... I believe your explanation is a bit unclear and would suggest a text some thing like this : When the U-boat submerges the header tank systempressure is kept constant, equal to a liquid column height from the compensating pipes sea inlet in the external fueltanks and the top of the header tank waterlevel, regardless the divingdepth of the U-Boat. The internal fuel tanks are shut to the external compensating system by the hull valves "a" on plate 10. 
Tore

[SnakeDoc]

Hi Tore,

while cruising submerged (using electric motors), did you shut the internal fuel tanks to the external compensating system? I mean, if it was common practise to isolate them from the external pressure?

In the KTB from the 2nd war patrol of U663 there are described some damages:

Schaden: 25 cm langer Riβ in TZ 3 durch Sull Mannloch, Riβstelle nach innen gedruckt. TB 1 und 2 innen ständig unter Druck. Wassereinbruch 8 t in 3 Std. im Dieselraum aus Entwässerungsschalter.

My translation:

Damages: The coaming of the manhole of the main ballast tank 3 torn. The edges are bent inside. Internal fuel oil tanks 1 and 2 remain under (external?) pressure. Water intake 8 tons per 3 hours in diesel engine room through the bilge/drain system.

From the description I suppose, that internal fuel oil tanks are somehow no more pressure resistant. And thus my initial question...

And by the way - what do you think about this torn of the coaming? As far as I know, the only manholes of the main ballast tank 3 are located in the control room, so I wonder, how they could damaged (and if the coaming is needed at all inside the boat)?

--
Thanks, regards
Maciek

[tore]

Maciek.
As a rule we shut all the boardvalves not needed when diving and for sure the compensating water to the inboard fueltanks.
With regard to the manhole and damage on MBT 3 I wander what caused the damage, was it by blowing the tank? or was it depthcharging or deepdiving. As adviced previously U 926 got a damage on MBT 3 by blowing.
MBT 3 has separate Kingstons and blowing and venting valves for starboard and port side. On several drawings the tank is drawn and  marked as MBT 3 port and stb. Between the port and starboard side of the tank there is a center bulkhead, I believe not pressureproof, you can see this on several drawings and on U-historia images the bulkhead is used for supporting the bearings for the  operating rods for the Kingstons on both sides. In this bulkhead you have a manhole see my image below, I should not expect a coaming on this cover. I guess you can easily damage this bulkhead if the differential pressure between the two sides become to large, but I am at a loss to explain how they could observe the damage . This is just a far fetched idea and bad assumption from my side." TB 1 und 2 staendig unter druck" does not give much meaning to me. The tanks have reliefvalves both for pressure and under pressure, moreover you could shut the hullvalve and relieve the pressure in to the wastetank or other inside tanks.

[Don Prince]

Hello Mr. Tore and Maciek,

It looks like all the damages to MBT 3 were the results of a depth charge attack from a destroyer on the 13th and 14th of December 42 during their 1st war patrol.  Overall, U-663 was just too close to the pounding of depth charges for 2 days.  MBT 1 and MBT 5 have comb type grilling over the vents on the top side.  I could see them getting pushed inward from depth charge explosion pressure...

U-663 History
1st patrol 5.11.42 left Bergen returned Brest - Damaged 31.12.42 (repairs took about 2 months)
                4.3.43 left Brest returned 6.3.43
2nd patrol 10.3.43 left Brest returned Brest 4.4.43 - no damage reports
3rd patrol 5.5.43 left Brest - 7.5.43 attacked by aircraft Sunderland (RAAF) declared lost 8.5.43 - no survivors.

The very short life span of U-663.

Regards,
Don_

[Don Prince]

Hello Mr. Tore,

I changed page 78 as suggested and uploaded the latest version of Skizzenbuch to dropbox...

Regards,
Don_

[tore]

Maciek.
The report of U 663 says "Wassereinbruch 8 t in 3 Std im dieselraum aus entwaesserungs schalter." I guess in case of depthcharging, without shutting the board valve exposing the internal compensating system for excessive pressure fluctuation like a depthcharging, the two cocks marked on the drawing might burst and you get a substantial  waterflow into the engine room via the broken entwaesserungs schalter. It t. However you could avoid exposing the internal fueltanks for same pressure fluctuations even with open hull valve by shutting the valves "c" to the tank 1 and 2. It looks indeed like they did not shut the hullvalve, neither did they shut the c valves when the increased internal pressure occurred which could be a fatal mistake.
Tore

[SnakeDoc]

Hi Gentlemen,

Tore, thank you for your answer.

With regard to the manhole and damage on MBT 3 I wander what caused the damage, was it by blowing the tank? or was it depthcharging or deepdiving.

The damages were caused by depth charging. While pursuing SC-123 convoy, she was spotted by HMS Vanessa (D29) and forced to dive. During the first (of four) attack, destroyer dropped eight well-aimed depth-charges.

TB 1 und 2 staendig unter druck" does not give much meaning to me. The tanks have reliefvalves both for pressure and under pressure, moreover you could shut the hullvalve and relieve the pressure in to the wastetank or other inside tanks.

I suspected, that somehow the tanks themselves or the compensating installation was not tight and exposed to the external sea pressure.

The report of U 663 says "Wassereinbruch 8 t in 3 Std im dieselraum aus entwaesserungs schalter." I guess in case of depthcharging, without shutting the board valve exposing the internal compensating system for excessive pressure fluctuation like a depthcharging, the two cocks marked on the drawing might burst and you get a substantial  waterflow into the engine room via the broken entwaesserungs schalter. It t. However you could avoid exposing the internal fueltanks for same pressure fluctuations even with open hull valve by shutting the valves "c" to the tank 1 and 2. It looks indeed like they did not shut the hullvalve, neither did they shut the c valves when the increased internal pressure occurred which could be a fatal mistake.

It makes sense to me.

--
Thanks, regards
Maciek

[tore]

Don
Your latest update seems OK to me. Time has come for me to move up to my summerfarm very remote in the deep forrests which means I shall be without internet from tommorrow and  for some time, may be up to two weeks, before I get a satelite connection. In the meantime I shall have a further study of your Skizzenbuch and revert to same when I`ll be on line again. 

Tore

[Don Prince]

Hello Mr. Tore,


Have a good vacation on your summer farm in the forest and I hope its not too far from neighbors or friends.


Regards,
Don_

[Don Prince]

Hello Mr. Tore and Maciek,

Today, I just completed my permission list from the three (3) web sites which provided the documents for Skizzenbuch:

uboatarchive.net - Skizzenbuch 34 plates, U-570 reports and B/W photos
u-historia.com - Line drawings and a few color photos
uboataces.com - Most of the high resolution color photos we used for illustrations came from their CD

I will most likely sign and return the book contract to Schiffer Publishing, Ltd., next week...  The publisher suggested I get a small photo of my contributors and a short Biography.  I plan on replacing the photo of me at the end of the book with a better photo when I was at the Chicago Museum of Science and Industry.   I'm not sure if it will happen, but I asked my friend Jak. P. Mallmann Showell who has written many books about the history of U-Boats during WWII to do a short "Forward."  If that happens, I think it would be great!

Regards.
Don_

[tore]

Don.
I am finally back on the net. Good to learn you probably shall sign the contract next week. I have checked the skizzenbook up to page 77 and have a comment on page 69 "e" valve selection on the fuel daytank. I think you somehow got it wrong. Below I have made a sketch showing how the selectioncock is working I guess is  selfexplaining. Otherwise I cannot find anything wrong. However it strikes me when you substitute  an original German manual text translated  into English with an alternative text which may be a simpler to understand for a layman, you maintain the translated text from original German documents as well . For a layman the translated manual text is not easy to read as the English text sometimes can give an impression that the translator in spite of using the correct words sometimes do not fully understand the meaning of what is translated. It is not easy to translate technical manuals as you really have to know the working of the items you describe.  I guess what I am trying to say is, you get a double text on the same subject which might be confusing for the layman reader, for a professional however the original translated text shall be OK and that`s perhaps why you kept it.
Tore

[tore]

Don.
Skizzenbuch.  I don`t fully understand your text on page 79 under plate 10. The system works like this: If submerged and the hullvale "a" leaks or is left open, the internal pipesystem shall be exposed to the seapressure but is protected by the reliefvalve "f" in the engineroom. The internal fueltanks 1 and 2 are protected by the shut off valves "C". If these valves are open each fuel tank has a unit consisting of a reliefvalve for overpressure "f1"and under pressure "f2", fitted with a manometer for the absolute pressure prevailing in the tanks. These units protect the tanks for both over- and underpressures.
See my answer to Maciek 2651 and 2653.
Tore

[tore]

Don.
Skizzenbuch. On page 88 you have an elaborate description of the assumed waterlevel height of the compensating tank introducing the keel and the wind deflector. This might be complicated to follow for the average reader and as all the figures we have of the tank  would be approximate anyhow, I guess it would be simpler just to  introduce the approximate figures directly. As you see on my image below the watersupply pipe from the engines ends up in a pipe some 20 cm above the bottom of the tank to prevent a complete draining when the engines are stopped. When the engines are running the water is filling the tank until the overboard pipe approximately. 10 cm. from the top of the tank when the water goes overboard normally keeping the tank topped up 10 cm. from the topcover. Further the bottom of internal fueltanks are not going all the way to the lowest part of the pressurehull (see my sketch). This means that surfaced an estimated pressure of the internal fueltanks open to the system might vary  between 740 and 700 cm. watercolumn approximately corresponding to 0.74 and 0.70 kg/cm2.  or 10,5 and 9,95 lbs/sq. inch.
Tore

[tore]

Don.
Having checked your Skizzenbook up to page 108, I have the following last remarks: Page 109 Safety valves . You have a remark on the safety valve (Reliefvalve) on the main blowingpanel dealing with the event that you had an air pressure supply of only 25 kg/cm2 or less that you could adjust the reliefvalve or improvise. In such unlikely event you don`t have to do any thing else to the relief valve or other components but blowing whatever you got of air so I suggest you skip that paragraph.
On your description of the electric aircompressor,first line lunching to be substituted with launching torpedoes .
The description of the Junker compressor I believe is superfluous as you have a description on page 92 through 97.
Tore

[tore]

Don.
Skizzenbuch page 116. Coolingwater. The header tank uses the water to pressurize the RFO tanks... I suggest you revise the text to: ...is used for pressurizing and watercompensating of all fueltanks except RFO 1. The excess water goes overboard via the external mufflers and headertank overflow.
On the same page you mention the coolingwater for the Junker, I suggest you change the text to:....... diesel powered unit having its own attached rotary vane coolingwater pump and external exhaust cooling watersystem via e3.

Page 123. The text starting with:  The engines were Krupp  for the VII Cs..... I think you quoted my text dealing with a description of the main engine of KNM Kaura ex U-995. As you know the VII Cs main engines could be Krupp Germania Werft or MAN the latter having the Buchi system exhaustdriven supercharger I suggest you rewrite the text to make it more general for the VII Cs.
By this your Skizzenbuch is checked up to page 133.
Tore

[tore]

Don.
Skizzenbuch page 157. Starting procedure main engine. I suggest you change the sentence .....the starting handle is put in a start position...... with: the startinghandle is put in a start position, air is admitted to the top cylinder of the starting valve pushing the valverod.....
Page 170. Stb. exhaust blowing valve in the engine room. You write this as black, it is green ( not very important as we did not have these colours on the valve wheels.
You describe correctly that the bores in the  main exhaust valves wheels were  for putting a bar into the wheel for a larger torque. We did not use the bar very often but waited until we reached some 2-4 meters depth creating a nice backpressure when we were grinding the outer exhaustvalve, however when we reached 5-6 meters the backpressure would be too large for the pneumatic motors to turn the valve disc so you had to be quick.
A minor thing, you are quoting some of my remarks where I am referring what I or we experienced or did under different circumstances like page on page 157 .... I personally checked the combustion by........It might give a confusing or even wrong impression without mentioning who are behind I or we. You could rewrite into a more general form skipping the we and I or quoting who is behind the statement, otherwise you get the blame for my possible mistakes .
Your Skizzenbuch has now been checked up to page 172.
Tore

[Don Prince]

Hello Mr. Tore,


Post 1752, I used your latest drawing as suggested.  Is the text OK?  I'm not sure you wanted me to change anything.  I have bee AWOL (Absent With Our Leave) for this weekend and will get back to work on Skizzenbuch.


Regards,
Don_

[Don Prince]

Hello Mr. Tore,


I believe I got everything updated...  I'm not too sure what you wanted me to change on page 109...  I left the paragraph in there about the Junkers compressor because of too much open space if deleted...


I uploaded the latest version of Skizzenbuch into dropbox...


Thank you for taking your time to correct my typing errors.  I don't usually have torpedoes for 'Lunch"!!!



Regards,
Don_

[tore]

Don.
Your reply #2664 I am not sure which drawing and text you are referring to as  post nos are just the a number indicating my total posts, could you refer to reply number?
I have checked your Skizzenbuch 1 before your update of today up to page 193 and have a few remarks. Page 187 clutch for hydroplanes you are quoting my description referring to the coloured sketch 2. paragraph. Somehow the green coloured part is quoted as wormwheel housing. The housing is not shown and the green parts are the e-motor worm gearwheel assembly.
On page 188 you have a funny misspelling ....... hydroplane setting while cursing   on the surface.....
On page 191 you are referring to the inclinometer (along ship) as showing the tilt, we normally used trim. There is another inclinometer showing the list ( atwartship tilt) I remember looking frequently on the device in rough weather in view of the battery acidspill. I guess it was in the control room but can`t find it on U-995, may be somebody pinched it.
Page 193....... Keel depth varies slightly depending on the loadfactor.... It depends on the sea salinity and temperature as well, you see it on the classification marks on every shipside.
As to your to days #2665 I shall revert later.
Tore

[Don Prince]

Hello Mr. Tore,


I made the suggested changes and spelling corrections...  I uploaded the latest version of Skizzenbuck to dropbox.


 "Hydroplane settings while cursing on the surface" was changed to "Hydroplane settings while cruising on the surface"  I guess I misspelled 'Cruising" and word automatically inserted "cursing"…… Then after that, it passed Spell Check!    Many times


Regards,
Don_

[tore]

Don.
Skizzenbuch1 of today:  page 78 text under image misprint .... height of the water column form the deck...... You are on most of the text concerning fueloil tanks as from page 78 and onwards referring to RFO tanks, you better check these texts as most of them concerns FO tanks and not only RFO (reserve fuel oil tanks).
Page 79 see my reply #2659
Page 116...... The RFO tanks and the excess water is drained back.... suggest you skip this sentence.
As far as I can see apart from the above correction everything is OK up to page 193.
Tore

[tore]

Don.
Skizzenbuch page 199. You describe the man operating the engine telegraph as giving order to the electrician and that he responds after the command is completed. This not quite the case, the engine telegraph is used both for giving orders to the dieselroom as well as the E-room depending on the prevailing propulsion configuration. In this case it could f.i. be a dieselconfiguration on a surface attack and the orders would have been given to the diesel engineers. In any case the order procedure is different from what is stated by you. The speed order is given by the officer on watch, only to be overruled by the CO, in that case he takes over the command. When the order is given to the helmsman wherever he is placed, he put the engine telegraph pointer to the ordered speed, repeating the order to the officer on watch (or CO) the order is transmitted to the diesel room or E-room depending on the configuration. The engineer or electrician put the telegraph pointer to the ordered speed prior to the execution, not after the order is executed, as a sign they have understood the order correctly and the helmsman report to the officer on watch.
The "speedgauges as you calls it" are called tachometers. Skizzenbook checked up to page 199.
Tore

[Don Prince]

Hello Mr. Tore,


I believe I have everything up to date...  I re-wrote 3 paragraphs  - pages 78, 116, and 199.  I believe they reflect your suggestions.  Please let me know if they are OK.  I uploaded the latest version of Skizzenbuch to dropbox...


Regards,
Don_

[tore]

Don.
Page 78. Normally when you use the compensating water you only pressurize the fuel tanks and do not have a water consumption. Only the bunker fueltanks selected to supply fuel to the diesel engine daytanks would require compensating water equal to that of one of the daytanks, a total capacity 730 litres. The engines have at normal cruising speed an average total consumption of say 420 litres/hour, so lets assume you top up the tank once pr. hour by 420 litres you have the average compensatingwater consumption. Compared to the total cooling water supply from the diesels say 40.000 litres/hour only 10% of the cooling water is used for watercompensating while cruising by diesels. So you statement..... most of the water is channeled to the fueltanks....should be corrected.
Page 199.   ... the engine room dieselengineer or the E-room electrician will respond with his telegraph unit after the command has been completed and then the.......
The engineer or the electrician acknowledge the order prior to the execution of the telegraph order.
Tore

[Don Prince]

Hello Mr. Tore,


I have a question about the muffler spark suppressor... Does it spray water onto the exhaust to extinguish the sparks?  I thought I read something about white smoke coming from the U-Boat exhaust (possibly steam)?  If that were the case, then they would only want to use the spark suppressor at night to eliminate that tell-tale glow of the U-Boat's exhaust so not to give away its location...


Regards,
Don_

[Don Prince]

Hello Mr. Tore.

Are these statements correct?

"The day tank has two sides and each has a capacity of 720 Liters"

"Compared to the cooling water supplied from the diesels approximately 4,000 liters/hour, only about 10% of the cooling water is used for water compensating while cruising by diesel."


If we top up the tank once an hour...  Then that means we switch tanks and top up the tank that was being used and we have an hour for the fuel to settle before switching again.  These sound more like hour tanks rather than day tanks...

Regards,
Don_

[tore]

Don.
 I don`t think you should take the daytank on a submarine literally. The expression is used by the enginecrew and comes from the merchant marine where they have the space for a 24 hours tank. You may use the expression setling tank or even headertank. I guess the total capacity for both tanks together is 720 liters in excess of 6 US barrels. If you look at the both tanks together I don`t think they have the capacity of a total of 12-13 barrels.  The tankcontent is not very much and indeed it is a short setling time, but it is better that taking the fuel directly from the bunkertanks. All these figures are only approximate figures roughly calculated by me to illustrate the working of the system.
Tore

[tore]

Don.
Spark arrestor. I think the VIICs have a number of different exhaust outlets and possibly spark arrestors. I have put up some 5-6 versions on the images below. So I have to answer you questions more generally. The sparkarrestors for submarines may be of two executions wet or dry. In the wet execution the engine coolingwater is sprayed into the arrestor or the gases are emitted into a coolingwater well  in case same is placed above the watersurface (sea) or the exhaust is emitted below the watersurface (sea) without a special casing for a spark arrestor. The latter execution was the original U-995 design, this has been changed on today museum U-995 as shown on the image. The dry sparkarrestor has an intricate system of baffel plates to arrest the sparks inside a casing.
Tore

[Don Prince]

Hello Mr. Tore,

I added the info you provided on the exhaust location and the spark suppressor on page 117.  I also added your info to page 78 and I did a lot of research and add some additional info as well.  However, as always -  if I got it wrong, then please tell me so and I will correct it.

I uploaded the latest version of Skizzenbuch to dropbox...

Regards,
Don_ 

[tore]

Don.
Page 78. Running one diesel at full ahead on one shaft using the generator to power the other shaft by E motor at half the propeller rpm as of the "diesel shaft" was a very seldom configuration. You would get an unequal load on the propellers requiring a constant  correction by the rudders, resulting in a increased hull resistance. Depending on circumstances as when you had to be at your destination and your battery charge, you choose the configuration. I guess normally I would have run both diesels at 3/4 load if no charging was required. If charging was required, as was very often the case, I would put on the battery charging on both diesels, and adjusting the load and rpm at the lowest specific fuelconsumption of the diesels. But we did not often made to much theoretical speculation around the matter, it is so many variables like hullresistance which varies with the  maintenance, optimal variable specific fuelconsumption of the diesels, weather, sea etc. A long story on these matters in an explanation of the daytank would possibly be confusing for the reader and take the focus from the daytank.

There is one fringe benefit with the water compensating system which we have not touched upon, the hot water sanitary system. From the headertank you have a fourth connection (drain)supplying warm seawater to the galley and the lavatories, see the image below, which I guess is self explanatory. Although the water consumption is fractional it is nevertheless worth while to mention.
Tore

[tore]

Don.
Your page 117 seems to be OK.
Tore

[tore]

Don.
Page 199 misprint..... attach periscope....
Checked up to page 237, more than half the Skizzen Buch OK  
Tore.

[Don Prince]

Hello Mr. Tore,

I read that they used the economy method for two reasons... 
1.  One diesel was down for repairs so it could not be online
2.  They were on a search grid and fuel was a concern because of a long patrol

I found another instance....
By May 1943 surfacing was fraught with danger, and standing orders from Admiral Godt (who took command of the U-Boat Arm when Donitz became C-in-C of the Navy) instructed captains to run on the surface with the U-Boats in neutral buoyancy, with one diesel and one electric motor running, and to be ready to dive at all times.

It looks like times were getting pretty desperate...

Regards,
Don_

[tore]

Don.
As mentioned many times before, operation of a submarine have many options both with regards to using the flexibility of the systems as well as sailing the boat in the best possible way under different circumstances. That takes skill and experience. However when you shall explain systems related to fuel consumptions I guess normal circumstances should be the reference. An easy way of doing that is by using the engine specific fuelconsumption. Down below I have put up a graph showing the specific fuelconsumption measured on the test bed for a VIIC GW engine. The waterbrake follows the propeller law. The red graph is the non supercharged range of the engine and as you see the lowest possible specific fuelconsumption is 180/g bhp hour achieved at app. 380 rpm and slightly in excess of 800 HP. The specific consumption is then about the same until you increase the rpm to app. 425. and 1000 bhp, then you got to switch in the supercharger and the efficiency of the engine drops (the Roots blower take a lot of energy) the specific fuelconsumption, yellow graph, is then increased to 188 g/bhp starting to raise further from 470 rpm. This graph can be used when you want to run the boat in a best possible fuelsaving way, however as I said before, there are many aspects in the operation of a submarine, fuelconsumption is only one of them..
Tore

[tore]

Don.
Skizzenbuch page 261 misprint ....attachperiscope.... page 262 misprint .... from the sten... . In your description of the periscopes- hydraulic may be it is worth while to mention the importance of having the periscope resting on the bottom stoppers while going deep. The reason for that is to releave the stresses on the wires. In the unlikely event of a cable snapping while the periscope is up, you`ll have an unarmed "torpedo" ramming the pressurehull bottom. Otherwise at f.i. 25 meter, the raising and lowering of the scope was an elegant way of adjusting the trim, when you only needed minor adjustment, by using the displacement of the periscopes as an adjustment tool.
Your skizzenbuch is checked OK up to page 274.
Tore

[tore]

Don.
Skizzenbuch. Page 247 2nd. lowest line misprint ..... toiled......
I have not checked the pages 277 up to 321 on the torpedoequipment.
On the ballast tanks and venting you are using a lot of drawings from U-historia, nominating the various items. I guess when you translate German into Spanish and then to English you might get some strange nominations, which deviates quite a bit from expressions and nominations previously used in your book. This can be confusing to your readers, moreover in the submarine language it is vital not to use different names for the same item. Examples are Divetanks / Ballasttanks, Hydroplanes/Diveplanes,Shut/Closed, Ventilationvalve/Ventvalve, Floodvalves/Kingstons etc. As the naval expressions deviates even between the English speaking countries it become difficult. I guess you have to chose US Navy or RN English.  I fully realize this is not easy when you quote different sources, although the different words might be correct, I guess it is a bit confusing for a reader but definitely cumbersome for the editor to correct.
The venting of the ballasttanks is an important part of a submarine, and you have some excellent images from U-historia, one thing is missing though. On the large handles for the vents of port and starboard MBT 3, MBT 2 and 4 the lockingpins are left out. Just imagine if the Kingstons were open and somebody accidentally grasped the handle.   Below is an image of the lockingpins in place.
You Skizzenbuch is checked up to page 340 except the pages mention above.
Tore

[tore]

Don.
If the MBT 2 and 4 were in RFO configuration both the gatevalves and the Kingstons would be shut and main ventvalve would`t work, the same goes for the emergency shut of the ventducts. MBT3 venting would`t work if kingstons were shut. Generally in harbour for a longer period, I guess normally all the kingstons were shut. I don`t think the greatest risk would be in harbour.
When at sea the order: "make ready for diving" is given and a number of actions take place to make the boat ready and after that is done an accidental pulling of the vent valvelever could be fatal. The locking pins are simple and quick to remove and is done as a part of the diving procedure. In wartime and surfaced in hostile waters I guess they would be left out all the time.
Tore

[Don Prince]

Hello Mr. Tore,

I went through a major upgrade to Skizzenbuch as suggested:
1.  I removed all references to the D designation for the Ballast tanks on both text and photos.
2.  The word Dive Tank was replaced with Ballast Tank
3.  The word Dive Plane/s was replaced with Hydroplane/s
4.  The word ventilation valve was replaced with vent valve
5.  The word flood valve for MBT 2, 3, and 4 was replaced with Kingston/s

I corrected page 199, 261, and 262 = Attack and not attach
I added periscope info on page 260
I added warm wash and shower water info on page 247
I added fuel consumption info on page 401

Mr Tore, I am very grateful for your suggestions about cleaning up all the inconsistencies...  If you see any other problems, them please adivse.

Regards,
Don_

[tore]

Don.
Checked your correction OK. A few remarks on page 401. The accurate outputs of the engine are measured on the testbed by having a waterbrake attached, the braking is done according to the propellerlaw. The output measured is the brake horse power BHP, not break.
I do not fully under stand the figures stated in you column: Mid war diesel engine reversing gear was removed. It is of course correct that the reversing gear was removed, but that does not influence the ahead output/rpm range of the engine which is the same as on the testbed graph. It might look as if you possibly show the outputs of the engines without a superharger, but the supercharger was not removed with the reversing system.
 On the direct reversible engines it was not possible to run astern with supercharger clutched in, it could be that you are showing these diesel astern figures.
In that case I suggest you call the column Astern figures for direct reversible dieselengines to prevent confusion, otherwise use the figures in the VIIC manual page 14, A ship info. I General.
Tore

[tore]

Don.
Skizzenbuch. Page 402 contains a short description of the thrustbearing, 403 a more elaborate description of same do you want both? Page 404 shaft break......- shaft brake.....Page 405 charging mode, you can run both engines in charging mode simultaneously as well. Page 406 ...the large red handwheel and the black starboard handwheel...... I believe on the museums U-995 they took fun in painting levers, handles and wheels, red for port equipment and green, not black, for starboard. Looks sometimes almost black on the photos though. Not very important in my time we did`t use these fancy colours. The propeller clutches are named differently, like Main clutch,E-motor clutch , Propeller clutch. The RN expression is Tail clutch, I personally like Propeller clutch. Anyhow as mentioned before, only one name for the thing would be preferable. Skizzenbuch checked OK up to page 410.
Tore 

[Don Prince]

Hello Mr. Tore,


If running on the surface and charging with both diesel engines, would that be considered a lighter charging mode?  If one diesel engine is dedicated to charging the batteries, then would that be considered a full charging mode?


If charging with both diesel engines while schnorcheling, they still have the 6 knots speed restriction; correct?


Regards,
Don_

[tore]

Don.
Charging with both diesels could be anything, low speed, high charge or high speed, low charge depending upon the requirement. The advantage is to have the same propellerload  on both propellers which mean you do not have to compensate an uneven load on the propellers by the rudders. Whether or not you have a full charging mode depend on the state of the batteries, what charge you can put into the batteries, you have to reduced the charging at the last part of the charge to prevent gassing and not to shorten the lifetime of your batteries.
6 knots restriction has nothing to do with the mode of charging it is merely a restriction due to the bending forces created on the schnorchelmast.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,

I made all the suggested corrections and the one in the Naxos section.  After thinking about Mr. Tore's comments about running both diesels engines and their e-motors as generators...  I was thinking and changed page 405.  I know me thinking is dangerous, but an I correct, or all messed up again? 

I uploaded the latest version of Skizzenbuch to dropbox for your review.  It looks like we are getting to the 400's pages and almost done...

Then I have to re-configure Skizzenbuch's pages for Schiffer, and I'm going to re-configure Skizzenbuch for my leather covered post binder.  I going to change the page layout so I don't need to worry about the binder spacing.

Regards,
Don_

[tore]

Don.
Skizzenbuch page 405. I believe it is OK and I don`t think you should elaborate this further as it could be a bit complicated. Instead of  making a long list of various configurations may be a general description is easier. As previously mentioned the engine performance graph is registered on the testbed waterbrake according to the propeller law. That is an ideal theoretical condition for an optimal propeller, which is useful for estimating vital engine figures. If you put a charge on top of the propeller load you upset the ideal load ( propeller load) and the engine performance both with regards to fuelconsumption and the max. load. I have made a new graph in our testbed scheme showing the max output and an assumed charging load graph (blue) showing how it would upset the performances. Kindly note these are not readings just an illustrating of my explanation. The engineers know how to avoid an overload and adjusting the fuelinjection according to the revs and exhausttemperatures, not by reading tables, as there are so many other variables like hull resistance,(draft and fouling) it is literally impossible to put everything in a list. With to days computers I presume it would be possible to make a programme, but I am that old that I trust human experience and know how before a machine .
Tore

[tore]

Don.
Page 404 ...shaftbreak....   Page407   Manual Clutch Drive ..... is to be engaor...... Page 411 ...... Air flow blower: Supercharger..... Mounted on the back side of the engine. Normally we refer to the back side of the engine  as towards the boardside ..We would say the supercharger is fitted on the aft end of the engine...
Checked OK up to page 412.
Tore

[tore]

Skizzenbuch.
 Page 375. I just stumbled over your remark on running the E compressor submerged due to excessive air pressure quoting Tauchvorschriften. It is a lot more problems than acid problem at the opening of the towerhatch. Overpressure have a negative influence on the human body, all the gauges including the depth gauges showing the wrong depth, the galley cooking the meal at higher temperatures  etc. and  is not desireable in the compartment of a submarine. As mentioned before when diving, leakages occur particularly on the diesel main exhaustvalves which always needed to be ground by the pneumatic motors which are expelling a substantial amount of air into the engineroom, moreover the inside venting of Q and other tanks all contributes to an overpressure as well and so are leakages and drains. All told, there was always an overpressure when diving, which should be taken care of. Hence if at all possible the E-compressor was started. Opening the towerhatch when the compartment had overpressure could come up with suprises, from the CO being shot overboard to the coocks pots and pan starting to boil like crazy. I have mentioned these events before, including a crewman always having a firm grip around the CO`s  ankles in case he had no time to release the overpressure prior to opening of the towerhatch.
Tore
 

[Don Prince]

Hello Mr. Tore,


I corrected pages 404, 407 and 411.  I also added a paragraph with the info you provided about Over Pressure on page 375.  I uploaded the latest version of Skizzenbuch to dropbox...


Regards,
Don_

[tore]

Don.
Page 411 the supercharger is fitted on the aft side of the engines.  Page 375 the overpressure ....you don`t have to cook at higher temperatures, it is simply that the laws of the thermodynamics makes the water starting boil at  higher temperatures. F.inst. if you put on the coffeepot it boils at 100 degrees C at normal atmospheric pressure, at higher pressures the coffee get hotter before it boils. This can have a substantial effect on the cocks pot and pans, if he has every kettle nicely simmering at an overpressure submerged and all of a sudden you are surfacing and the towerhatch is opened, releasing the overpressure, the pots and pans starts to boil vigorously spilling the food all over the galley .

Tore

[tore]

Don.
Skizzenbuch page  413 first generation schnorchel system. On the system sketch the airinlet pipe is coloured blue, however at the engineroom inlet valves on your sketch it is marked as if it enters the ventilation system as well as the diesel air inlet valve. As the text is saying the air enters only via the dieselair intake valve. See revised sketch below.
Tore

[tore]

Don.
Page 416. Schnorchelmast head  ....... inletcap and the masy..... 3rd. paragraph.......dieselebgine.....   ..... secon dieselengine.... the commander had to surfase.....
Page 418. On the schnorchel raising lowering ram assembly you  see two rods one on each side of the pistonrod. These are the guide rods for the guide shoe taking up the sideforces when raising/lowering the schnorchel mast, see image below.
Skizzenbuch checked up to page 419.
Tore

[Don Prince]

Hello Mr. Tore,

I believe I got all the corrections done and I changed out the schnorchel drawing and added the photo of the hydraulic ram.

I uploaded the latest version of Skizzenbuch to dropbox...

Regards,
Don_

[tore]

Don.
Your corrections seems to be OK.
Tore

[tore]

Don.
Skizzenbuch page 419. I see you refer to the CO of U 995 as the holder of the Knight Cross (Ritterkreutz) which is correct, but yet a bit on the borderline. Hans Georg Hess being the youngest CO ever of a U- boat was on one of his last missions with U-995 February 1945 and sighted a Norwegian freighter S/S Iddefjord of 6300 DWT in the harbour of the Norwegian town Kirkenes, unloading supplies to the inhabitants. At that time the town was recaptured from the Germans by Soviet troops. Allthough his orders were to go after the Murmansk convoys he called in his officers and said: Gentlemen how about an attack a la Prien, suggesting the should sneak into the harbour of Kirkenes and sink the Iddefjord. So they did and they launched 3 torpedoes registered 3 explosions which they recorded as hits. However non of the torpedoes were hits they exploded in the nearby rocks and Iddefjord sailed unharmed a few days later. The sinking of Iddefjord was recorded by the high command and CO Hess got his Ritterkreutz. He was confronted with this some 50- 60 years later at a meeting with some Norwegian merchant naval gunners in Kiel and answered he had been convinced he had sunk the Iddefjord.
It is correct that 8th of May 1945 U-995 was at the yard in Trondheim installing Schnorchel that save her from operation Deadlight as she was unfit for passage to Scotland.
Page 421. U 480 2ND. warpatrol. The report is very interesting and correspond to my experience during a 28 days test schnorchelling with KNM Kaura ex. U 995. The underpressure could be a bit unpleasant possibly more that an overpressure. We expelled the garbage in the same way by the torpedo tube without a piston, however we did not use cans, but bags which sometime bursted and fouled up the torpedotube much to the torpedopeoples dismay.
I have put up a table in order to visualize the effect of the pressure fluctuations by showing the changes of water boiling temperatures. The yellow parts are the normal underpressure and the green part the normal overpressure. Red are the figures at normal atmospheric pressure.
Skizzenbuch checked up page 423.
Tore
 

[tore]

Don.
Pages 425 to 441 not checked, pages 441 up to 444 checked OK.
Tore

[Don Prince]

Hello Mr. tore,

I had to change the write-up on page 376; the gas law would not actually work for the boiling point of water with changing pressure.  I found a formula on the internet:

Boiling Point = a constant (K = 49.161)  x Ln  [pressure(in Hg)] + 44.932

This seems to be very close to the chart that you posted.  I used the chart and changed the text because I didn't want the reader to attempt the formula (which I did not include), and use the Windows scientific calculator to check the results.  In addition, I found some very interesting info on under pressure when running with the schnorchel.

I uploaded the latest version of Skizzenbuch to dropbox. Please advise

Regards,
Don_

[tore]

Don.
I agree, the use of water in the demonstration of the ideal gas law is not very wise, as you see I deleted yesteday the formula.
Tore

[tore]

Don.
I checked your page 376 and think it is better. On a RN submarine the schnorchel float valve would shut and not close .
When mentioning the the battery electrolyte, this was of course one of the vital elements in staying submerged. Every morning and evening the chief electrician measured the specific gravity of the battery electrolyte and wrote the figures on a blackboard in the wardroom. We all kept an eye on that blackboard.
Tore

[tore]

Don.
Pages 442, 443,and 456 checked OK and that completes my checking of your Skizzenbuch. As to the Pillenwerfer I can briefly mention that this device was used to launch signal rockets as well, for instance during exercises and in case of emergencies .
I guess a book like yours never shall be flawless being packed with details from many sources of different qualities. Nevertheless it shall be an important source of information for people interested in submarines generally and the VIICs particularly.
Tore

[Don Prince]

Hello Mr. Tore,

Thank you for all the effort you have put into guiding me with Skizzenbuch in the current form.  I have to create a version for Schiffer Publishing with all the special characters, and one for my Leather post binder which is just a 1.75 inch binding side offset.  This is just a conversion process now that I have a final version in hand.

Kind regards,
Don_

[tore]

Don.
Wishing you good luck with your next step.
Tore

[falo]

Hi Tore,


just another question: Did you use the Enigma-Machine for coded radio transmitting on "Kaura"?


In a a tv documentation I saw a few years ago it was reported that the Royal Navy gave the Enigma Machines to there allies (for example India) with the evidence that they never cracked the code (as an quality attribute). From then on the Royal Navy was again able to read along the radio transmission. Unless I'am mistaken this secret was uncovered in the nineteens by the RN themselves.


Thanks and regards
falo

[tore]

Falo.
This is a bit off my line, but I don't think we ever used the German Enigma Machines. As in my time we were member of the NATO having its own standard of Crypto- and Cipher systems of which I don`t know very much. I guess the bases for the German crypto-/cipher machines was developed at the end of WW1 and commercially available in the thirties. I presume the Enigma has been refined many times since then. I should assume the value of revealing the German WW2 Enigma system was not the system as such, but rather to keep the news about the revealing secret so the Germans continued to used the same system unchanged. But as I said this was definitely not my field.
Tore

[falo]

Hi tore,


thanks for the information. Certainly you are right with the NATO standard. Funny to mention that during my army days in the mid eighties as a combat engineer I was also in touch with radio transmission and field telephone but I forgot all that NATO stuff until your answer. Maybe embarrassing to say but I thought always Norway was neutral as Sweden during the cold war. Sorry for that wrong conclusion   


Thanks again and regards
falo

[Don Prince]

Hello Falo,

If you are interested in the Enigma, then this youtube video may be of interest.  It tells the story of the Bombe development by the National Cash Register Company (now the NCR Corporation) after the German Kriegsmarine went from the 3 rotor to the 4 rotor Enigma machine.

https://www.youtube.com/watch?v=v33IPQwKFKY

I started working for NCR back in February 25, 1963 and retired on April 1, 2009, after a little over 46 years of service.

Regards,
Don_

[falo]

Hi Don,


thanks for the interesting youtube link.


Regards
falo

[tore]

Don.
I had a quick glance on your latest Skizzenbuch page 341 dealing with the venting of the MBT 2 & 4 port and stb. The residue venting valve for MBT2 port and stb. is named on your drawing as aux valve. I suggest you use residue venting valve. Likewise the emergency shut off valves for MBT 2&4 port and stb are named as ventilation valve , I suggest you name same emergency shut off valves to prevent confusion. The same goes for the emergency shut off vent valves for MBT 3.
The venting system is one of the prime systems on a submarine and the VIICs have one of the most extensive mechanical operation systems for ballast tank venting. For a quick operation of the MBT 3, 2&4 the venting of these tanks are done by large pull- push levers in the control room. The mechanical rods and links for these vents might be a bit complicated and I believe some of the drawings shown are not 100% correct. At the order Dive,Dive, Dive the levers are pulled down opening the ventvalves and as soon as the air has escaped, the vents are shut  by pushing the levers up in a more or less horizontal position. On plate 28 and the U historia drawing for some reason the shut position is shown with the levers down. In that case the levers would be an obstruction for the crew under normal circumstances. Normally they are up shut as on the museums U-995.
Down below I have tried to explain the open/shut position of these very important vents.
Tore

[Don Prince]

Hello Mr. Tore,


I have had an issue with the Vent levers ever since I seen both the u-historia.com drawings and the original German Plate 28!  Below I have redrawn both Ventilation levers...  What do you think?


Regards,
Don_

[tore]

Don
Somehow it says I am not allowed to enter ( enlarged) the image, but the way I see the small image it seems to be OK. In order to explain the details of this intricate rod and lever system I have made a sketch showing the principle, rather than the correct angles and length of the levers /links. May be it is selfexplanatory
Tore

[Don Prince]

Hello Mr. Tore,


Actually your previous composite diagram was very helpful to me to get an understanding of hoe the ventilation lever works within the ventilation bridge casting. 


1.  I colored the vent valve drive plate red - it has two studs which are yoked by the 2 drive links in blue.
2.  When the ventilation lever is pulled down, the upper and lower drive arms move as one because of the common link between them.
3.  The lower drive arm swings outward pulling the valve drive shaft downward.  The drive plate studs riding in the bridge casting side raceways assure the shaft is pulled straight down, and not off to the side and the vent valve is opened.
4.  The locking pin is inserted into the holes in the ventilation bridge casting in front or the joint where the drive links are connected to the lower drive arm.  The pin will stop the lower drive srm ans conversely the upper drive ard and ventilation lever from moving.  There is no hole in the drive links for the locking pin ( this would be a point of weakness.


I updated Skizzenbuch with this information as well as all your suggested corrections to the u-historia.com drawings and the latest version is in dropbox...


Regards,
Don_. 

[tore]

Don.
I guess the latest correction in your Skizzenbuch is OK. However on page 339 you are referring to MBT 2,3 and 4 stating  the hullvalves are normally open at sea and these levers are used for initiating a dive for these tanks. I suggest you change the text to: the Kingstons ( Flutklappen) are normally open at sea and the ventvalves are shut by the levers immediately after the ballasttanks air has been evacuated.
Tore

[tore]

Don.
I guess you correction is OK, however I wonder what you mean by .....(MBT 2 and MBT 4 floodvalves are normally open as well)... MBT 2 and 4 are as you know saddletanks and in RN English we usually call the floodvalves for these tanks the same as for MBT 3, Kingstons. Kingston valves, named after an English engineer John Kingston who died mid 1800,  were used for any type of ship hull flooding valve, however in the RN submarine language it became the nomination for the ballast tank floodvalves.
Whether or not you should name the ballasttanks by capital letters I really don`t know. I usually indicate the ballasttanks by capital letters for some reasons. Anyhow I agree you should standardize the names whatever name you use.
Tore

[Don Prince]

Hello Mr. Tore,


I really apologize for wasting your time.... I was attempting to convert some of the Skizzenbuch files and Word keeps crashing and corrupting my files.  So I have removed all applications from my computer except for Word, and hopefully I can get this mess straightened out.


1.  I have changed the text on page 330
2.  I changed the header and text on page 339
3.  Page 340 - corrected the top left drawing - Ventilation lever up to match the valve position
4.  Page 340 - corrected the lower left drawing - ventilation lever up to match the valve position and renamed the valve to Emergency Shut-Off Valve
5.  Page 340 - corrected the lower right drawing - redrew the ventilation valve to the open position to match the lever
6.  Page 340 - corrected the text in the 2 paragraphs
7.  Page 341 - used your drawing that I modified
8.  Page 341 - corrected the text in the lower paragraph
9.  Page 342 - corrected the drawing to indicate a "Residual Vent Valve," a "Emergency Shut-Off Valve."


I have uploaded Skizzenbuch to dropbox for your review.  It is very important for me to get through this review process with you.  I have been reading through some of the earlier pages and I can see as my education evolved and some of the old stuff was just terribly written.


One question...  In order to start standardizing words;  Should it be 'MBT 3" or "MBT3" without the space for all the tanks?


Kind regards,
Don

[Don Prince]

Hello Mr. Tore,


The flood valved for the saddle tanks are normally open during a war patrol; is that not correct?


Don_

[Don Prince]

Should the Saddle tank flood valves be called Knigstons too?

[SnakeDoc]

Hi Tore,

The flood valved for the saddle tanks are normally open during a war patrol; is that not correct?

It depends on the current function of the saddle tanks. If saddle tanks are used for fuel storage, the flood valves are shut. When the fuel was used, tanks are converted into ballast tanks - the gate valves in the vent ducts are opened, the vent valve levers are unsealed and the flood valves are opened.

--
Regards
Maciek

[tore]

Don.
If we leave out the saddletanks in the fuel bunker configuration where the saddle tank Kingstons are shut all the time, the saddletank Kingstons in ballast configuration are normally open as for the MBT 3 during war patrol. The Kingstons are time consuming to operate, and you want to be able to dive quickly.
As I mention previously  in the RN English we usually call all the MBT floodvalves for Kingstons, including the saddletanks floodvalves, so if you choose to use RN submarine English in you Skizzenbuch, I guess you should use that nomination. Otherwise sometimes Kingston were used in surfacevessels for several hullvalves, but for submarines only for MBT floodvalves.
I usually use MBT 3 with space but cannot guarantee this is 100%  correct. Anyhow in order to prevent confusion stick to the same language throughout the whole book being aware that the US submarine language is most probably deviating to some extent from the RN English.
Tore

[tore]

Don.
I have  checked your text and sketches on page 340 through 342 and I think your text is better and easier to understand. May be you should skip the ventilation levers for the ventlevers, as we normally use vent  for ballast tanks venting and ventilation for the compartment ventilation.
Tore

[tore]

Don.
My post (sketch) no 2716 of June 4 Th was not very good, showing only how the rods and levers worked, but they were all drawn in different and wrong positions which might be a bit confusing. I have tried to correct this by the sketch below showing MBT 2 & 4 stb assembly. As you probably have noticed there is a slight deviation between the A bracket for the vent valve of MBT 3 and MBT 2 & 4. this does not change the working principle for the two assemblies which are the same.

I made a bad mistake not mentioning I made use of Simons excellent drawings below to show the position of the stb ventvalves outside the pressurehull. My sincere apology Simon.


Tore

[NZSnowman]

Tore, how did the German's seal the rod that went through the pressure hull? Was there a series of O-rings?

[tore]

Simon.
I am  very sorry making a bad mistake not mentioning I made use of one of your exellent drawings in showing the position of the ventvalve for MBT 2 & 4 stb outside the pressurehull.
Kindly accept my apology for this regrettable mistake.
Tore

[NZSnowman]

Hi Tore

No worry and you do not need apology about the using my drawing. What is why I do them so people are use them.
 
It was not what I was writing about. It was "How did the German's seal the rod that went through the pressure hull? Was there a series of O-rings?"

[tore]

Simon.
I don`t think there is a O ring packing box, more a conventional stuffing box with a laternring having a greaseinjection and gland.
Tore

[tore]

Simon.
I guess more like the box below.

Tore

[NZSnowman]

Would the packing be wood?

[tore]

Simon.
I don`t think so Simon, wood like Lingnum Vitae is usually used in heavy loaded rotating shafts having submerged bearing like propeller shaft. For smaller spindles like valvestems etc having reciprocating movements stuffing fibers like shown below are cut into excact length to fit the circumference of the shaft, you don`t wind it around but each "ring" are separately placed on top of the other having the cut on different place for each ring. The fibermaterial could be of different materials, even asbestos and "impregnated" with graphite. Having a lantern ring between the two stuffings allows grease to be injected both for sealing and lubrication of the reciprocating shaft.
Tore

[tore]

Simon.
Knowing your likings for small details here is the greasing details. The greasing of the stuffingboxes was done by a grease gun to one common grease nipple serving two stuffingboxes as shown on the image below.

Tore

[tore]

Simon.
You are a snowman getting you master on snow, make a living working with the snow on the southern hemisphere and going into your winter season,we are in my part of the world still figthing to get rid of the thing. We still have snow which shall last for months. Below is an image taken last week from the highway between our two major cities Oslo and Bergen crossing the mountains. The snow is still up to 11 meters and yesterday they had to dig out one of the skiing slopes as they couldn't find the skilift. So if you need practice come to this area.
Tore

[Don Prince]

Hello Mr. Tore,


Why don't they ship some of that snow to the US West coast?  California is rationing water use right now; Maximum 10 minute shower and 1 per day per person, and the lawns are not to be watered/just burn out.  The population kept on increasing and the environmentalist would not let then build water reservoirs because there was a smelt (snail darter) found down stream that was endangered 25 to 30 years ago.  Last year they found one snail darter in the entire river basin that dumps into the pacific Ocean.  Now about 75% of the Sierra snow melt dumps into the pacific Ocean while California burns out...  This country is all screwed-up with environmentalist and political correctness idiots gone wild!


Regards,
Don_

[tore]

Don.
Our dams are overfilled and all the snow would create an unbelievable flooding with spectacular waterfalls and possible damages. When all that meltingwater is ending up in the fjords it creates an interesting situation from a submariners point of view as numerous of layers of water with different salinity is acting like an Asdic mirror,a dreamarea for a submarine CO to exercise and practise hide and seek play.
Tore

[VIC20]

Tore,
I'm still here 
There was a gap between the periscope tube and the opening hole/shaft (the open tub like thing on the bottom of the command room) when the periscope in the command room was retraced right?


I guess it is hard to explain but could you describe the sound of both periscopes?

[VIC20]

I forgot that I can quickly show what I mean 

[Don Prince]

Hello Mr. Tore,

Reviewing the text for:

GW Sequencing…

First you open the main starting air supply valve to admit starting air to the cylinder starting valves and the starting air manifold. Then you move the starting handle to start, on a direct reversible engine you pass the "umsteuer" maneuvering position; the run position and nothing happens. The run position is only the venting valve open the others shut. On the maneuvering position, the starting lever has to stay in reverse position in order to start the reversing process.

When the starting handle is in the start position, air is admitted to the top piston on the cylinder starting valves; pushing the rocker arms down to engage the rollers on the starting cams. On direct reversible engines the cams are selected by the ahead/astern handle and the engine start to run on air. When you obtain the proper revs you move the handle to "betrieb" or "run" the valves supplying air to the "umsteuer" mechanism and top of the cylinder starting valves are shut, and the vent valve on the air manifold opens and the spring under the top piston on the cylinder starting valve forces the piston up lifting the starting valve rollers from the camshaft.

Everything makes sense to me except the first paragraph, and the next to the last sentence -- "The run position is only the venting valve open the others shut."  Could you clarify this sentence?  What others shut?


Regards,
Don_

[tore]

Tore,
I'm still here 
There was a gap between the periscope tube and the opening hole/shaft (the open tub like thing on the bottom of the command room) when the periscope in the command room was retraced right?

Mark.
It is indeed an open space between the periscope well and the navigation periscope, however on the museum U 995 they put a cover on the well.
Tore


I guess it is hard to explain but could you describe the sound of both periscopes?

[tore]

Don.
Would the sketch below give you an explanation? The distribution air manifold with valves is encircled in red and showing the valves in run position.
Tore

[SnakeDoc]

Hi Mark,

There was a gap between the periscope tube and the opening hole/shaft (the open tub like thing on the bottom of the command room) when the periscope in the command room was retraced right?

See attached picture, presenting the control room of HMS Graph (ex-U570). You can see the periscope lowered into the periscope well.

I guess it is hard to explain but could you describe the sound of both periscopes?

Here you can hear the sound when operating the periscope on USS Pampanito (Balao class submarine):
http://archive.hnsa.org/sound/pampanito/periscope.mp3
Her periscopes were also raised and lowered hydraulically.
It sounds quite similarly to the periscope sound in the Das Boot movie.

--
Regards
Maciek

[VIC20]

Thanks, I know this graph picture but I totally forgot to look on it. 

[tore]

Mark.
The sound picture of the periscopes for a VIIC is slightly different and may be variable. The hydraulic system has three large accumulators storing the hydraulic energy and prior to any planned attack this storage was filled by IMO pumps which usually was not necessary to run during the attack, sound picture no 1. The sound picture for the navigation/air periscope is that of an IMO pump running as a motor operating a winch via a geardrive. Sound picture no 2. all told not very high. The attack periscope has two sounds, that of lowering and raising the periscope (very much the same as for the navigation periscope) and the turning of the periscope including the operator which is controlled by foot pedals of the operator and driven by an IMO pump running like a motor via gear assembly. As far as I remember slightly more noisy than the lowering/raising sound and a bit more "whining". Sound picture no 3.
Otherwise I agree with Maciek, may be the movie " Das Boot" gives the best indication.
Down below is the present day U- 995 controlroom with navigation periscope well covered.
Tore

[SnakeDoc]

Hi Gentlemen,

while looking for the photo of the uncovered periscope well, among the other photos from HMS Graph I have found some worth of interests.
13.jpg - the vent of the (I'm not sure) MBT3 or saddle tanks starboard. In the VOZM book, it is described as MBT 3 vent.

16.jpg - the vent valve lever of the MBT 3 port

10.jpg, 11.jpg - there are visible two handles for operating the flood valves (kingstons) of the MBT 3. As we know, there were 3 pairs of the flood valves. These handles are inserted into the slots for the forward two pairs (see the picture "flood valves.jpg").

21.jpg - this photo presents the charging the U-Boat HP air flaks (or less likely the oxygen flask). This photo is quite similar to the photo published in the VOMZ book, but is taken under quite different angle, so more interior of the magnetic compass casing is visible. What is interesting here, are the visible handles of the emergency blowing manifold. You can clearly see the handles with thickening for easier recognition by divers (see the picture "emergency blowing manifold.jpg").

Don, I think you have to revise picture on the page 218 in your Skizzenbuch and move the ovals, which marks the location of the emergency blowing manifold to the magnetic compass casing.

--
Regards
Maciek

[tore]

Maciek.
Interesting photos, 11 shows the timeconsuming operation of the MBT 3 double kingstons and 13, I agree, must be the ventvalve of MBT 3 stb. 16 shows a different view as well as giving a better understanding than the overpainted assembly from the museum U 995. Thanks a lot.
Tore

[Don Prince]

Hello Mr. Tore,


Just to verify my insanity... Would the posted drawing ID Tags be correct?


Kind regards,
Don_

[Don Prince]

Hello Mr. Tore,

Would you please elaborate about operating the Kingstons for MBT 3?  There looks to be 2 locations in the forward control room floor (1 on each side of the keel) to operate the dual Kingston valves, and there looks to be a smaller opening for a grease gun to lubricate the valves drive structure.

I believe there would be 2 locations in the aft control room floor (1 on each side of the keel) to operate the single Kingston valves, and I would assume the same lubrication installation.

1. Once these valves for MBT 3 were set open for a war patrol, was there ever a need, or reason, to make adjustments?

2. How do you know the Kingston Valve were fully opened, was there a hard mechanical stopping point?

Regards,
Don_ 

[tore]

Don.
I guess your question on tagging would be answered by the image below. As far as I know the U-570 still had the rescue/markerbuoy in the casing.
Tore

[tore]

Don.
Your assumption on the aft kingstons is correct. In the center of MBT 3 it is a bulkhead separating port and starboard MBT 3. On this bulkhead the bearings for the kingston rotating operation rods were mounted. The driverods ended in a threaded part, on this part a yoke having a central nut (inside threads) moved axially as you turned the rod, thus moved the Kingstons as shown on the image. In the outer positions the yoke nut have a stop at the end of the travel against the end bearings.
I cannot recall we ever had to adjust the Kingstons and they are either fully shut or fully open. As they open outwards, the seapressure keep the Kingston firmly shut when in shut position. 
Tore

[Don Prince]

Hello Mr. Tore,


Thanks for the info...  Do you happen to have a photo of the GW Diesel engine full control panel?  I would like to see the Ahead/Astern Handle...


Regards,
Don_

[tore]

Don.
The photos I have are all of very poor quality. It is really not much visual changes between the direct reversible and the non reversible engines. The reversing handle was removed but the reversing plate was kept at the maneuvering stand. The most significant change was the removal of the large vertical reversing cylinder and the smaller vertical slide valve. On my image below is the removed items indicated.
Tore

[Don Prince]

Hello Mr. Tore,


I'm still having issues with the Reversing Handle....  See my attached photo.  In the Reversing Handle is on the Left side (blue arrow), then it looks like the handles interfere with each other???  However, if it were on the right side (red arrow), then it looks like the handles will work???


Regards,
Don_

[tore]

Don.
I believe you are mixing the fuelhandle with a reversinghandle. As your image shows the ME maneuvering stand of U-995 being non reversible engine the reversing lever is removed only the residue plate and some visible rods are left. On your photo the fuelhandle is to the far left, the starting lever is in centre and the removed reversinghandle is should be to the right.
Se my image below.
Tore

[tore]

Don.
As I have no original photo of the reversinghandle I made one on the U-995 maneuverstand don't forget it is a fake!
Tore

[Don Prince]

Hello Mr. Tore,


The last few drawings clears things up for me....  I called the middle handle the "Maneuvering Handle" because on U-995 there are 2 selections "Operate/Run" on the top, and "Start" at the bottom.


On a reversing engine you have; Stop, Operate/Run, Reverse, and Start.  So, The Maneuvering Handle seems to make more sense to me because it's much more than just a starting handle...  Am I wrong?


Regards,
Don_

[tore]

Don.
I guess it is named starting handle because it primarily operates the valves in the starting air manifold. The other positions for a direct reversible engine are required to engage or disengage the interlocks in the system to prevent major dammages. On plate 29 you see the starting system. I don`t think I would call one handle maneuvering handle as all the three handles are really handles on the maneuvering stand taking part in the maneuver.
Tore

[Don Prince]

Hello Mr. Tore,


After much consideration...  I am going to go back to "Starting Handle" as the  name.


Kind regards,
Don_

[tore]

Don.
That`s what we called it.
Tore

[Don Prince]

Hello Mr. Tore,


On U-boats after 1943, the hand-wheel for MBT 1 was mounted on the aft control room pressure hull bulkhead.  Do you have any photos or drawings that showed the MBT 1 hand-wheel located in the aft torpedo room?  I assume the change was made to have all ballast tanks controlled from the control room...


Regards,
Don_

[SnakeDoc]

Hi Don,

I guess you are wrong here.The vents of all ballast tanks were controlled from control room from beginning. The remote control for bow buoyancy tank on the forward bulkhead was added later.
The driving shaft for the operating MBT1 vent valve is going from control room to the aft torpedo room through petty officers room, diesel engine room and electric motor room. In each room, to the shaft is attached the driving hand-wheel, for operating the shaft and vent valve when part of the shaft is damaged.

--
Regards
Maciek

[tore]

Don.
I fully agree to Maciek  last post. In the aft pressure bulkhead of the controlroom you have two ventwheels. The stb being for the residue venting of MBT 2 port and stb. The rod goes all the way to the engineroom where a 90 degrees bevelgear takes the rod through the pressurehull right up front of the stb. main exhaust blowing valve and then to the two residue ventvalves. The other wheel on the port side  operates the rod to the MBT 1 ventvalve. The rods goes on port side to the engineroom. Just aft of the port main exhaustvalve a chaindrive connect the drive to stb side and the rod goes now on the stb. side to the aft torpedoroom where it goes trough the end of the pressurehull at  frame 0 and the externally to the MBT1 vent..
Both vent wheels are normally operated from the controlroom and the wheels can be locked as for the other main ventvalves levers and wheels.
See my image below.
Tore

[Don Prince]

Hello Mr. Tore,


It was late and I just got things wrong!  The last photos put posted...  Could you provide me with the top photo only of the 2 hand-wheels for MBT 2 Residual and MBT 1 without the remarks because I use Times New Roman type set...


Thanks,
Don_

[tore]

Don.
I guess this shall do.
Tore

[Don Prince]

Hello Mr. Tore,


Super fast...  Thank you!  I just notices something - The diesel maneuvering panels have the levers arranged differently on the port and starboard side.  They simply moved the fuel and starting lever assembly from one side to the other, but that changes the location relative to the center walk-way (They are not Mirrored).  They have the reversing lever on the inside of the moved assembly next to the starting air hand-wheel.


I was getting confused (very likely) when you posted the photo showing the reversing lever on the left of the fuel and starting levers, and my photo showed the reversing location to be to the right.


Regards,
Don_

[tore]

Don.
You shall find this done with a number of items on the engine f.inst the fuelpumps which are the same. This is much cheaper to produce and you have only one item to keep as sparepart on board.
Tore

[Don Prince]

Hello Mr. Tore,


My understanding of reverse...  If the engine was running forward, then you stopped the engine.  To go in reverse, you select reverse with the starting lever, and then move the ahead/astern handle to astern and once the cams are shifted you move the starting handle to start. at this point the diesel engine can run in reverse.


Now we stop the engine again.  To go forward again you move the starting handle to reverse again.  Now you can move the ahead/astern handle to ahead.  Once the cams are shifted, then you can move the starting handle to start and away we go in forward...


I know I skipped a lot of details, but I just want to know if I have a basic idea as to how it works...


Kind regards,
Don_

[Don Prince]

Hello Mr. Tore,


The attached photo shows the panel on the other diesel engine and the Ahead Astern unit has a very wide space from the other levers.  That way the ahead/astern and the fuel lever handles can point toward earh other still and not interfere with each other.


Regards,
Don_

[tore]

Don.
If you want to simplify the description of the reversing system, may be you could use a text like this:
The starting handle has four position 1. start,  2. run,  3.  stop and 4. reversing. These different positions are necessary to release and engage the various interlocks in the reversing/ starting system.
The start position allows the starting air to enter the cylinders, and when the engine runs on air, the fuelhandle is moved to run to allow fuel to the cylinders. When the engine is running on fuel, the starting handle is moved to run position shutting the starting air to the cylinders. The startinghandle in  stop position locks the system when the fuelhandle is put to 0 fuel.
The reversing is done by placing the starting lever in reversing postion thereby engaging the starting interlocks,  releasing the reversing interlocks and admitting air to the reversingcylinder slide. When the interlocks are released they allow the reversinghandle to move into the ahead/astern position and the reversing cylinder is shifting the camshaft in the required position, when this sequence is completed,the starting interlocks are again released and you repeat the starting procedure in the new direction of rotation.
This description is not complete but gives a rough idea of the starting/ reversing procedures.
Tore

[tore]

Don.
Your "discovery" of the maneuverstand not being mirrored touch upon an interesting subject. Modern warfare is depending upon access to rawmateriel, people and industrial capacity. The Nazi Germany was limited in all and in the submarine construction details you might find clever details to come around their problem. The most common submarine engine was built in two versions, 6 and 9 cylinder using as many interchangeable components as possible. This was done by making symmetrical parts which could be assembled 180 degrees avoiding mirror ( two) executions in a twin engine installation. For instance the large items as the cylinderblocks were made in 3 cylinders symmetrical units. The same casting could be assembled in 2x3 units= 6 cylinder units for the VIIC and 3x3 units=9 cylinder for the IX, being symmetrical they could be turned 180 degrees and used both as a port and stb. engine. On the image below you see the U 995 6 cyl. engine connectionflange for the two 3 cylinder blocks. Between the blocks there is an inch visible gap between the cylindercovers because of the extra space required for the cylinderblock flanges.
For the fuelpumps they followed the same system. One type of fuel pump for port and stb. engine, not mirrored on the other engine, but simply turning the fuelpump 180 degrees. By that you face  a problem as the fuelplunger is controlled by an axially movement of the fuelrack and by having the maneuverstands on both engines up front and governor in the aft you have to change the direction of the fuelrack movement on one of the engines. On the port engine the fuelrack moves aft to increase the fuelinjection on stb engines it moves fwd.
The movement of the fuelhandle and the hydraulic governor are the same on both engines, a change of the fuelrack direction is done by introducing and extra lever in the rack linkage for the fuellever and the governor on one of the engines.
The whole engine is full of such solutions, like on cylindercovers, supercharger etc. etc. and means a vast saving in production and storage.
On the raw materiel you see substitutes for brass and nickel alloy. F.inst on the U 995 all the text plates on the maneuvering stand are a very dull aluminium instead of brassplates, even the gauges have in some cases substitutes for brass.
I remember during "WW2" all the nickel- and coppercoins were withdrawn from the circulation and substituted by iron and zinc and all the brass ashtrays and handles were removed from the streetcars and trains to be used in the German warproduction.
May be difficult to understand today, but dead serious in my younger days and, as you see ,an impact on the submarine constructions as well.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you for the information about the construction of the Krupp GW Diesel engines...  I have been working on the Schiffer version of Skizzenbuch; compressing pages and adding some of the great info provided by you lately.


Regards,
Don_

[Don Prince]

Hello Mr. Tore,


Skizzenbuch page 411 - the Roots Supercharger - The yellow pipe supplying air to the cylinders - Are there 6 pipes for the Type VIIC Krupp GW Diesel engines, one for each cylinder?


Regards,
Don_

[tore]

Don.
The air supply to the cylinders goes via separate ducts for each cylinder. The system works as follows: When the engine is on moderate load e.g. Roots blower not engaged, the air is sucked in by the engine via several inlets on the common air manifold. From the manifold the air goes via separate airducts to each cylinder.
When the Roots blower is clutched in, the clutchhandle simontaneously turns the rotating valves at the separate normal aspirated air inlets on the manifold, shutting the inletvalves and the compressed air is supplied via the separate air inlet for the Roots blower being compressed and then discharged to the airmanifold.  The compressed air is then supply to the cylinders via the separate airducts. Down below I have tried to make an image using one of Simon exellent drawings.
Tore

[tore]

Don.
Another important large item is used on both starboard and port engine. The cylindercover, which is designed with starting valve, fuelvalve and safety valve in the centerline thus the cover is symmetrical to this line. However on the 180 degrees turned cover the exhaust and inlet valves  change places. This is compensated by having the valves in cages, a seawatercooled cage for the exhaustvalve and a noncooled version for the inlet valves. The outside construction and dimensions are the same for both versions and they fit in both corresponding pockets in the cylindercover, however the coolingwater outlet from the cylindercover to the exhaust valvecage must be replaced on the 180 degrees version. This is done by having two coolingwater outlets symmetrically placed on the cover, the outlet not in use, being blanked off by a blindflange. Various smaller pipes as venting- and lubrication pipes are adapted as well, but the idea of having one cover fitting both engines is obtained which simplify the sparepart storage (and cost).
Down below is an imaged where I am trying to explain the system and again using some of Simons images.


Tore

[tore]

Don.
I realise may be the outlet coolingwater from the cylindercover to the exhaustvalve casing might be a bit unclear. Down below is an image which shows the system. The full flow coolingwater from the relevant cylinder enters a regulating valve where part of the water goes to the valvecage the rest to the exhaust manifold. The outlet from the cage enters the regulatingvalve and leave together with the bypassed enginecooling water to the exhaust manifold.
Tore

[Don Prince]

Hello Mr. Tore,


The drawing you provided has 2 items that I relabeled.  However, when I make the image small enough to upload it's not very readable...


1st item - Super charger clutch handle
2nd item - Foldable starting air handle


Are these the correct label?


Regards,
Don_

[tore]

Don.
Correct, maybe " foldable starting wheel handle" would be better. It seems as if the quality of the image is not very good, down below I am mailing a new larger image (max. allowable) may be it is better.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you...  The Super charger manometer, isn't that the Exhaust pressure manometer for when blowing the ballast tanks?


Regards,
Don_

[tore]

Yes Don. This is an old image with a wrong text. The manometers are used for adjusting the exhaust blowingvalves (next to the roots blower) for the ballasttanks.
Tore

[tore]

Don.
Down below is an image where I have used one of Simons images to turn the stb. main engine cylinder block 180 degrees as well as the fitting of the port exhaustmanifold.
As you see the exhaustmanifold consist of two different parts, when the cylinder block is turned, the cylinder covers air inlets becomes the exhaust outlets. The exhaust manifold aft part, being slightly longer than the other is then placed up fwd to match the new exhaust outlets, thereby the same exhaustmanifold can be used for both engines.
As previously mentioned the movement of the fuelrack is changed when the fuelpumps are turned 180 degrees as well, the direction is indicated on the image. However as you want to have the identical movement of the maneuvering handles for both engines you overcome this by adopting the linkage of the maneuveringstand for on the engines.
 As to the governors and the servomotors, they are not turned 180 degrees and same execution is on stb. and port engine, pretty much as for the maneuveringstand. The governor and servo linkage is adopted to overcome the non turning of the servo as well.  As a description of the system require an understanding of the governor and the servo which might be a bit outside the scope of your Skizzenbuch, but in case you want to go into this details just let me know.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,

As you all know Skizzenbuch is composed of 3 Word document files because of crashing and corruption issues with MS Word and large dot doc files. I have gone through Skizzenbuch in the past few months and reformatted it to a MS Word standard for a 11 x 17 format and ran grammar check and spell check. I have re-sized and edited the photos for the best possible color and contrast within the limits of the original photos.

During the grammar check, I had to change some of the wording to get through the process, but not to any great extent. In the past month, I have amended several pages and added 2 others. The final page count is 459 pages, so I believe Schiffer Publishing will make Skizzenbuck a 2 volume set.

I have uploaded the last 1/3rd section into dropbox, the file name is "Skizzenbuch 11 x 17 - 3.pdf"...

Mr. Tore, would you please check pages 340, 348, 349, and 358 for a sanity check.

Maciek, would you please check pages 397, and 407, and again for a sanity check.

You all are welcome to browse the last third and make any comment. I will work on compiling the new formatted version into one complete file this weekend. That will be the version that goes to Schiffer Publishing for approval. I had to learn how to convert XLS to a DOS Text file, and then add the German special characters for the 34 Plate description pages. I had to learn to create Word columns in a document for several pages, in order to run grammar check on the document (I learned that offsets and simple spacing really screws things up).

After all this, I have to reformat Skizzenbuch again to match their publishing printer standards which does not support any formatting standard, no columns, no tables , etc.  They needed a Word formatted document as a reference.  I will find out in a few weeks how to reformat Skizzenbuch.

This is a real hassle - I can take my PDF version of Skizzenbuch to Office Depot, or Staples and have it printed for my leather post binder with NO conversion.  Their printer is compatible with an Adobe PDF formatted file and several other formats.

Kind regards,
Don_

[tore]

Don.
The lay out looks much better. I have just read page thru 328 thru 337. And have following remarks:
Page 328 ....using ventilation levers..... ventlevers ..... located in the aft controlroom ceiling.... We don't`have ceiling
               on boad ships and particularly not on submarines. Better use upper part of pressure hull.
Page 329 In the list of fueltank capacities you have included the small fueloil collecting tank but omitted the the fuel oil
               daytanks (header tanks) I suggest you include the daytanks as well.
Page 334  .... both handwheels have a lock.... change to both ... vent handwheels ... not to mix up with the ventilation handwheels.
Page 335 .... crank to open and close..... change to shut.
Page 336 ... larger  lever for MBT 2 and MBT 4.. I guess you are fooled by the camera angle as both levers are about the same size. The levers for MBT 2&4 have bends which make it look as if they are shorter. I suggest you use: the aft levers are for MBT 3 port and stb. the fwd levers are for MBT 2&4 port and stb.
Page 337 ....saddletanks kingstons are normally open as well. May be you should add : .. when in ballast configuration.
               U-historia image.  It seems you have Googled the Spanish text, I suggest the following:
                 8  pressurehull. (14a) watergauges for regulating tank 2 and (14 b) regulating and reseve fuel oil tank 1. (15) Trim-, aux bilge and     floodpump.
Tore

[Don Prince]

Hello Mr. Tore,


Do you remember if the Day tank was directly above the Dirty oil storage tank.  If so I can use the same distance from the center of gravity in the table (-9.5)...


Regards,
Don_

[tore]

Don.
I believe the aft part of the dirty f.o. tank is about 1/2 a frame fwd of the fwd part of the daytank.
Tore

[tore]

Don.
Skizzenbuch page 340,348,349 and 358. The isometric image on page 341 does not show the centre bulkhead in  MBT 3 thus not the fixing of the operatingrod bearings for the kingstons.
Page 343 image of the bow buoyancy tank marked ventilation valve,.... vent valve.
Page 348 basic starting sequence..... 5. move the starting lever to run .... lifting the cylinder starting air rollers from the starting cams and shutting starting air to                  the cylinderstarting valve.
Page 349 GW Maneuvering Panel Sequencing. I believe you are more or less describing, in different words, the same sequence as on page 348. Suggest you give a condensed ( and incomplete) description of the reversing instead, may be as follows:
Reversing.
Starting lever is placed in the reversing position, this vent the top piston of the cylinder starting valve, lifting the camrollers free from the camshaft at the same time air is admitted to the reversing slide.  The reversing handle is then put in astern position, this movement lift the exhaust-and inletrollers free from the camshaft. The camshaft is now ready to be moved axially. Air is admitted from the reversing slide to the reversing cylinder which move the camshaft axially and placing the astern cams under the valve pushrod rollers which now are lowered on to the cams. As soon as the camshaft is in the astern position, the interlocks are released and the engine can be started now astern as previously described


Coming weekend I shall be away from the internet I hope to be back Monday.
Tore
the push rods rollers can now be placed on the asterncams, the engine is ready to run astern and starting can be done as previously described.


 

[Don Prince]

Hello Mr. Tore and Maciek,

I made all the changes as suggested, and fixed the 3D MBT 3 drawing...  I have completed the MS Word document where there are no offsets, and I used columns to get everything aligned. I re-indexed the file and had to break Skizzenbuch up into 4 files because the 3rd file got too large and was crashing Word and corrupting the file.  I uploaded the latest version "Skizzenbuch 11 x 17 - M" (M = merged) to dropbox.  This is my final version for Schiffer Publishing, Ltd; Spell and Grammar checked - pending information corrections.

Maciek - I updated the RADAR, Naxos and Wanze section with some new info.  I would appreciate if you would review it and provide any comments.  I believe you are better qualified than I on this subject matter, and most others.

Mr. Tore -  You are the expert on all things that pertains to the Type VII C U-Boat, and I value your opinion and always take your suggestions.

Kind regards,
Don_

[tore]

Don.
I started to read the Skizzebuch all over again. Here are my remarks up to page 170.
Page 38 ..negative bouyancy tank.... In RN submarine english this is a word never used, we call it the Q tank, neither do we used the constructed word express, we simply use : blow Q!     
Page 78 .... the pipe to the right is a drainpipe.... It is a hot sea water supplypipe to the galley and the sanatary system.
Page 117 Exhaust port and spark arrestor.  .... and possibly spark arrestor... here is a capital p wrongly used.
Page 123..... or a MAN with a Bachi exhaust.....It is a Buchi exhaust... the u is a german letter having two dots on the top "u
[size=0px]           [/size][size=0px]    .......[/size] The vibration damper... better use torsional vibration damper.
Page 170 The MBT 3 blowing manifold (exterior to the pressure hull)  ..... exhaust blowing manifold ... not to be confused with the HP air blowing                         manifold inside the pressure hull.
Tore

[tore]

Don.
Checked up to page 176
Page 170 I believe a better image is my new one below.
Page 172 Starboard side ceiling does not exists........ stb. side upper pressurehull.
Page 173  Same as on page 172 ceiling...
               The reason for MBT 3 dual system of venting,kingstons, hp blowing and exhaustblowing is it is a center bulkhead in the MBT 3 thus you have port and                                starboard.
Page 174 Down below is perhaps a better image of the residual venting bevelgear.
Tore

[tore]

Don.
Skizzenbuch comments.
Page 177  ...... aproximately 10 meter waterclolumn of fresh..... Possibly better: ... 10 meter column of fresh water at 4 degrees.....
Page 182... the forward and aft hydroplanes are mounted on common shaft... can be misunderstood, possibly better ... the port and stb hydroplanes are mounted on a common shaft...
Page 183....Possibly better: .. the large handwheel on the left is the emergency handcontrol of the fwd hydroplanes and the handwheel to the right, the emergency hand operation of the aft hydroplanes. The normal control is carried out by the electric push buttons on the BBC controlbox in the center of the handwheels.
Page 184...The two diveplane stations... the two hydroplane stations...   .... to manual at the clutch near the dive plane.... hydroplane.
Fuerungsslange mit gewinde- threaded operation rod.  Kreutz kopf -crosshead.
Page 195 ... so when silent running was needed the telegraph could be sill... still...   Last paragraph  I guess you should change this paragraph as the procedure is:  the order is given, the telegraph is set to the order, the reciever acknowledge the order immedeately and then execute the order, thus the reciever do not wait to execute the order before he answer by the telegraph.
Page 196... There are two arrows red and green, not black.
Page 197.. the engineer or electrician will answer ( as mention above) when the order is recieved before the order is executed.
Skizzenbuch up to page 200 checked.
Tore


 

[tore]

Don.
Skizzenbuch
Page 206 inspection manhole MTB 3 ... this is a manhole in the center bulkhead of MBT 3 may be you should name it : inspection manhole centerbulkhead MBT 3.
The following pages up to 209 deals with the with the  Q tanks. I guess we have discussed it before, but to me using "negative buoyancy tank"for Q is strange, in fact all the ballasttanks are negative buoyancy tanks when diving. It is a long and difficult word which we never used in RN English. Untertriebzelle is a much better German word for the tank and so is Q for quick diving. As you are quite frequently using, to me, the correct name "Q", I guess you should stick to the one and same word in your book. Another word you are frequently using in the following pages concerning the periscope is "wench". I am not familiar with this word, as we in RN English use "Winch". Is it a US word?
I have looked so far through all the pages up to 320 apart from the torpedo pages and have so far not any remarks.
Tore

[tore]

Don.
Skizzenbuch
Page 337.... of the controlroom there are 4 ventilation lever bridges...... venting..   Left image 4 ventpipe- ventilation pipe. 11 Shut off cock.
Page 338[size=78%] ...[/size]Image left  Ventilation of Waterballast.... Venting...Image lower left Driveshaft opening closing- shutting. ... opening closing          lever-   shutting.
Page 339 Venting ...... by large pull-push levers in the controlroom ceiling.... upper part of pressurehull. ..., and ballast tank no 4....ballast and RFO tank no 4.   .... if  the Uboat had any dammage to the airtrunk f.i.by enemy aircraft machinegunfire......
Page 342  Image ventilation valve- ventvalve.Page 343 ..... bow buoyancy tank was located in the ceiling.... upper part of pressurehull. Lower left...eliminating the ceiling mounted handwheel  upper pressurehull.
Page 344 .... with the interlocks in the ceiling ..... aft torpedo room ceiling.... upper pressure hull.

Tore

[tore]

Don continuing the Skizzenbuch.
Page 347 ... shifting shaft for forward or reverse...  astern. In RN english Reversing means the operation where the engine is shifting either to ahead or astern. Hence you can be reversing the engine from astern to ahead.
Page 349  2nd section 2nd last paragraph ....extra required space required...2nd last sentence ... the gauges having aluminium  was substituted... as substitute ...
k verblockung = interlock.
Page  352....translation of text plate 29 a.  A funny misprint Analassen-Anlassen .
The following pages up to page 400 deals with electrical details which I presume you take care of yourshelf.



Tore

[Don Prince]

Hello Mr. Tore,

Thank you for the excellent review work...  For my part, my spelling error was really funny and really stupid!

"Winch" is a mechanical device; as you know...

"Wench" is what pirates called women with loose morals...

and that was not picked up with MS Word Spell or Grammar Check!!!

Regards,
Don_

[tore]

Don.
I see, I have spent quite a few years in Caribbean waters but never met a wench, put it in your Skizzenbuch dictionary together with Analassen.
Tore

[Don Prince]

Hello Mr. Tore,


Page 337, item 3 on the u-historia drawing is a "Ventilation Pipe" correct?
Regards,
Don_

[tore]

Don.
Absolutely, 3 is the port ventilaton pipe. Below I have made an image showing the two ducts stb and port.
Tore

[Don Prince]

Hello Mr. Tore,


When U-995 was caught in the North Sea gale and damaged in 1953; were the emergency shut-off valves used because of damage to the air trunks outside of the pressure hull?


Regards,
Don_

[tore]

Don.
The damage was primarely done to the casing and the sturdy pipings and ducts inside the casing were intact.
Tore

[Don Prince]

Hello Mr. Tore,


The photo I had of under the deck has the common trunk missing for MBT 2 and MBT 4...  Was that a result of the storm damage?  If so, then the emergency shut-off valves would need to be used...


Regards,
Don_