Tores mailbox VIIC and VIIC/41 operation and technical details

[Don Prince]

Hello Simon,


I was looking at your drawing new2u and now I see where you have configured in the D2 tanks residual vent valves b1 in your WorkingDrawingV03.  Could the d1 control valve wheels be in the ceiling of the diesel room?  That sounds like a Mr. Tore question, if he has not already address the issue.


My offer still stands...  Simon if you ever decide to publish a book with all your Type VIIc drawings, then I would be one of the first in line to purchase a copy.  Your work is that good!


Regards,
Don_

[tore]

Don.
Some time ago we discussed these valves see page 53 thru 55 in this thread. However I better sum up: The venting system of both the main venting MBT 2 and 4 as well as the residueventing MBT 2 have all fairly long external venting pipes which are controlled from the inside by common ventvalves for quick handling. The main venting of MBT 2 and 4  port and stb from CR and  the residueventing MBT 2 port and  stb from the CR and engineroom. This implies some external piping which might be susceptible to damages which could be fatal. To overcome this risk the system has valves close to each MBTs so you can shut off  each tank separately eliminating the external vent pipe. These valves should be operated from inside.  The valves are having spindles going through the pressurehull and ending up in a removable T bar on plate 6. The valves seems not to be fitted on the residue venting system and thus no valvespindles in the engineroom.  To make it even more complicated to you, the MBT 2 and 4 port and stb. have a 3rd valve in the ventduct outside the pressurehull, these are gatevalves and used for shutting off the tanks while used as fuel bunkertanks. The gatevalves are placed outside the pressurehull under the casing and are not operated from inside the pressurehull thus not valvewheels in the engineroom which is according to plan16.
Tore

[tore]

Don.
Emergency ventvalve MBT 4 port.
Further to my post this morning I show you a bad photo of what I believe could be the valvespindle of the port MBT4s emergency shut off valve for the ventline. I Guess it`s situated between frame 47 and 48 slightly aft of the navigation periscope. The starbord valve is hard to spot as on all the photos I have, a lot of stuff are in the way.The same goes for the valves of MBT2, you shall probably find the spindles in some of the upper small cabinets in the PO mess aft of the CR.
Tore

[SnakeDoc]

Hi Tore,

To make it even more complicated to you, the MBT 2 and 4 port and stb. have a 3rd valve in the ventduct outside the pressurehull, these are gatevalves and used for shutting off the tanks while used as fuel bunkertanks. The gatevalves are placed outside the pressurehull under the casing and are not operated from inside the pressurehull thus not valvewheels in the engineroom which is according to plan16.

Accidentally I have found something related with the gate valves. See this Deutsche Wochenschau: http://www.youtube.com/watch?v=aqdvK2ZtxoA , since 7:30. The reader says something like: Bei schwerer Wetter muß ein Tauchbunker aufgestellt werden. I think, that camera operator recorded operation of converting Tauchbunker from fuel tank to ballast tank mode, when the crew member opened gate valve on the venting duct.


--
Regards
Maciek

[tore]

Maciek.
Unbelievable what you are noticing. Indeed I guess the man on deck seems to open the gatevalve on fuel/ ballast tank 4 port. which means it is converted into a ballasttank by using a T bar on the valve from the casingdeck under bad wheather.
Tore 

[NZSnowman]

Great spotting Maciek!

It looks like I will need to update my drawing, from a hex shape to a square shape (7:37) peg on top of the valve 

Simon
 

[Don Prince]

Hi Simon,


It looks like the crewman is holding a "T" bar tool with a collar on the end of the shaft with a recessed square for fitting over the screw to unlock the access door (the tool)in the deck to the valve below.  the crewman also has a 2nd tool in his hand that looks like a double hook with a square cut-out to access the valve (The tool 2).  I'm not sure why it was designed like that?  Am I right on this?  (see photos)


Regards,
Don

[NZSnowman]

Don, yes on the 'square'. I will need to change my drawing from hex shape to a square shape

The hatch covers for these valves are different between the older and the newer style of decks of Type VII’s.
 
For the newer style of deck, the hatch cover for tank 1 valve is long/narrow because of the large lower Wintergarten (left of drawing) and tank 4 is just a key hole in the deck.

[Don Prince]

Hello Mr. Tore,


I must have been sleeping...  I totally missed the photo of the Q tank Kingston (now believed to be Mushroom) valve spindles in the photo.  I modified the photo so that I will not miss that again.


Is it normal for the valve wheel or handle not to be on the valve shaft?  I bet the Captain would really get up set if the crewman said they can't find the valve wheel during an crash dive and they can't express the Q tanks!!!


Regards,
Don_

[NZSnowman]

Hi Simon,


It looks like the crewman is holding a "T" bar tool with a collar on the end of the shaft with a recessed square for fitting over the screw to unlock the access door (the tool)in the deck to the valve below.  the crewman also has a 2nd tool in his hand that looks like a double hook with a square cut-out to access the valve (The tool 2).  I'm not sure why it was designed like that?  Am I right on this?  (see photos)


Regards,
Don

I also saw the 2nd tool and was wondering what its for

[tore]

Don.
The spindles which you have marked are the spindles for the MBTS 4 aft Kingstons. If you look at page 111 on this thread you`ll see Maciek correction and the special mushrom floodvalve fixed wheelhandle. This valve have a much smaller floodarea than the adjacent MBT4 Kingstons as discussed.
Tore 

[tore]

Don.
Valves and Kingstons spindle.
On the VIICs a number of valves end in a spindle without handle or wheels. You have several reasons for that. Spacesaving and preventing accidental opening of special important valves. It is normally used on valves not so frequent in operated. The CO don`t have to worry about the Q,  the floodvalve wheelhandle is always there.
Tore

[tore]

Simon and Don.
Nice to see you are back Simon. The strange tool you have noticed is a wheelclaw. The tool is used on wheelhandles on valves which are hard to open. You put one "claw" on the spoke and the other on the wheelrim thereby you get a rod giving you a better momentum for opening the valve.
Tore

[VIC20]

Hello Tore,


Simon pointed me to this great thread, I'm developing a Type VII simulation game.
It's amazing to read what kind of details you remember after many decades! I hope you could answer me some questions (unfortunately actually I have a lot of questions).


- I'm currently working on the simulation of the G.W. engine for my game.
The load is simulated with a simple calculation (propeller law) so it's like a test bed.
http://www.wolves-of-the-atlantic.com/downloads/Enginetest/Enginetest.html
(It will load the Unity plugin to play the simulation which is harmless. Ignore the bad graphics, it's just to give me a primitive visualization)


My biggest problem with the simulation is the acceleration of the engine itself because it's impossible for me to simulate the resistance caused by each part of the engine. I went with the power delivered to the shaft as basis of my simulation instead.
Basically the drag of the working propeller and the diameter and weight of the propeller and shaft are limiting the acceleration and revolutions per minute. The engine power itself is based on the amount of fuel per revolution (can be controlled with the slider).
It seems that the simulation matches the real world thing. But what about the time it takes to accelerate engine RPM? I have absolutely no idea how fast such an engine can accelerate to different RPMs.


- And the fuel consumption shown in the simulation, does it make any sense to you?


- Another question is the AK speed (highest continuous) which should be 470 RPM, was it really possible to run the engine at 470 RPM for longer times? And 490 RPM for something like half an hour?


- From what I've read on the Type VII manual I think the governor limits RPM to not exceed 490 RPM + 10% (which would be 539 RPM). How fast does this governor work? I think it pushes a kind of lever to limit the fuel inflow, does it have a "way" from 490 to 539 RPM or does it instantly limit fuel inflow?


- The manual says the engine can't be started with the supercharger clutched in. And the supercharger can't be clutched in below 390 RPM.
Also the fuel lever can't be moved to a higher position than something that would result in about 420 RPM unless the supercharger is clutched in. Now my really stupid question: do you have to declutch the supercharger when going from higher speed to below 390 RPM???


- What is the minimum RPM the engine can run at?


- do you remember the RPM (or loss of speed) when charging batteries (at the different drive modes)?


- Is it correct that you can engage the clutch of the diesel while the engine is running up to 350 RPM? What when you switch from diesel to E-Machines? The E-Machine operate at a maximum of 280-295 RPM, do you need to reduce the diesel RPM to below 300 RPM before you clutch in the E-machine or isn't it necessary (manual says the generator can work as a brake when propellors break through the water surface in bad weather).


- how long does it take to stop and start engines to reverse?


enough questions 


regards


Mark

[tore]

Mark.
Welcome to the thread, yes it is indeed a lot of interesting questions which I need a bit time to answer. Please be aware of the many alternative ways you can operate the engines. Singel engine, dual engine, engines declutched completely from shafting, clutched in E generators, clutched in propellers, run with different batterycharging , combination of propulsion and  batterycharging, various type of schnorchling etc. I`ll try go into  into your questions one by one if you have patience with a man going on 86. I`ll probably have a few answers ready by today.
Tore