Tores mailbox VIIC and VIIC/41 operation and technical details

[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