Author Topic: Tores mailbox VIIC and VIIC/41 operation and technical details (Read 665685 times)

tore · « **Reply #3200 on:** 06 Nov , 2016, 03:37 »

Simon.
The drains m are situated in the ventingducts for the saddle ballasttanks under the casingdeck and has nothing to do with the RFO tk.1 or neg boyancy tanks.The drains are operated from outside the pressure hull to the sea.
Tore

NZSnowman · « **Reply #3201 on:** 06 Nov , 2016, 05:56 »

Quote from: tore on 06 Nov , 2016, 03:37

Simon.
The drains m are situated in the ventingducts for the saddle ballasttanks under the casingdeck and has nothing to do with the RFO tk.1 or neg boyancy tanks.The drains are operated from outside the pressure hull to the sea.
Tore

What diameter do you think the drain would be?

tore · « **Reply #3202 on:** 06 Nov , 2016, 06:58 »

Simon.
I guess you found the diameter of the exhaust silencer drains previously and that diameter would probably match the vent duct drain.
Tore

karel · « **Reply #3203 on:** 22 Nov , 2016, 08:15 »

Hi guys. Been super busy trying to get the multiplayer to work. Good news is that everything seems to be syncing correctly. I can pull levers and dials and information gets transferred trough the network to another player.

So i have been trying to figure out how the speed command system worked on u-boat. I see that there is engine order telegraph in command room and there is engine order receiver in motor room.
If i had to guess then someone from command room dials in the command and it gets copied to the engine room telegraph? Then this information is used to adjust the motor speed manually by machinist?
But i also see a hand lever on order telegraph that is in the diesel room and i am not sure what is the reason. How did this all work exactly?

Many thanks.
Karel

tore · « **Reply #3204 on:** 22 Nov , 2016, 10:44 »

Karel.
The engine telegraph system consist of the order telegraphs, e.g. the telegraphs setting the orders. You have two sets (port and stb) of telegraphs one set in the conningtower and one set in the control room transmitting the COs or officer of watchs order to the dieselengineroom or e-motor room.
The orders given can be both direction of propellerrevs and the speed. For the dieselengines on the VIICs built after 1942 there was no reversing hence the dieselengine telegraphs could only order ahead revs and speed. As can be seen on the image below the telegraph could order increase of revs by 10, diesel engine operation or e-motor operation as well as batterycharging. Maneuvring of uboats delivered later 1942, like alongside the jetty, you used solely the E-motors.
When the engine order is given by the CO or officer of the watch, the helmsman put the orderlever in the ordered position which is transmitted to the diesel engine- or E-room. Prior to the execution of the order the engineer answeres, acknowledges, the order by putting the lever in the same position as the orderlever and adjust the engine. Likewise in the E- room where the electricians carry out the order in the same way.
When an order is given, a sound is made and a red light is flashing only to be stopped when the oder is acknowledged by the engine telegraphhandle.
Tore

karel · « **Reply #3205 on:** 22 Nov , 2016, 11:16 »

Thank you.

Just to make sure if i get this correctly on how the information is switched between telegraphs.

When i give an order from command room and put the handle on full forward, when will the needle on my telegraph move to the forward position? Will it move only after the machinist has acknowledged the order by moving his handle?

So when i move handle on my telegraph the needle moves on diesel room telegraph. Machinist then acknowledges that order by moving his telegraph handle to the needle position. And by doing so he activates the needle movement in the command room. This way the CO will get confirmation that the order has been carried on. Is this right?

tore · « **Reply #3206 on:** 22 Nov , 2016, 11:38 »

Karel.
I Guess you got it. When you put the telegraph handle in the control room to full ahead, the pointer on the engineroom telegraph moves to full ahead and the alarm is sounding and red ligth is flashing. When the acknowledgement handle on the engineroom telegraph is overlapping the new order pointer position, the flashing light and the audioalarm stops and the engineer is executing the order. In the controlroom the enginetelegraph aknowledgementpointer is moved simultaneously to match the orderhandle signalling the correct understanding and the audio alarm stops.
Tore

karel · « **Reply #3207 on:** 22 Nov , 2016, 12:41 »

That is wonderful

I am coding this behaviour into my game.

And thank you again so much. Not just for this, but for all the information that you have given in this thread over the years. Discovering this knowledge source has made my job so much easier. I really appreciate it.

Don Prince · « **Reply #3208 on:** 24 Nov , 2016, 10:09 »

Hello Mr. Tore and All,

Today is Thanksgiving here in the USA and I have a lot to be thankful for this year... I am very grateful for all the new friendships that I have made on this website. This past year, I went to Schiffer Publishing in Atglen, Pennsylvania, who will publish "Skizzenbuch" this Spring 2017. This book would not have been possible without the help from all of you. Mr Tore, without your knowledge and experiences, Skizzenbuch would have been just another book of facts and drawings about U-Boats. Your personal life experiences added the "Special Effects" to the book and will make a huge difference for the reader. As I said before, I have a lot to be thankful for this year...

Kind regards,
Don_

tore · « **Reply #3209 on:** 24 Nov , 2016, 12:02 »

Don.
Thank you for the kind words and greetings which I Return by sending you my card from my farm in the deep forrests of Norway. I wish you all the luck with your Skizzenbuch and judging from the many questions put forward on this thread I guess there is a marked. Looking forward to seeing the final result.
Tore

VIC20 · « **Reply #3210 on:** 30 Nov , 2016, 20:15 »

Hello again Tore and all others,

what about the telegraphs and audioalarm when running silent on E-Machines?

NZSnowman · « **Reply #3211 on:** 01 Dec , 2016, 02:49 »

Tore, we know that the Germans do not used Tab Washers on the internal pipe flanges bolts but used Tab Washers on all pipe flanges bolts that penetrated the pressure hull.

Do you think the Germans used Tab Washers on all the external pipe flanges outside the pressure hull or only on the pipe flanges that penetrated the pressure hull?

karel · « **Reply #3212 on:** 01 Dec , 2016, 03:06 »

Quote from: VIC20 on 30 Nov , 2016, 20:15

Hello again Tore and all others,

what about the telegraphs and audioalarm when running silent on E-Machines?

Not sure if i remember correctly but reading the u-boat manual when you were in silent mode there was no audioalarm at all. Only the light was blinking. There was a switch somewhere where you could control this. 3 modes. Off/Audioalarm & light bliking/ blinking only. I may be wrong. Have been reading so much information that it all becomes a mess in my head

But in game i this could be a cool extra layer of management. If you forget to manage telegraph switch modes when in silent run and give a new order with alarm then your noise level goes trough the roof and enemy could potentially locate your position.

tore · « **Reply #3213 on:** 01 Dec , 2016, 03:53 »

Quote from: NZSnowman on 01 Dec , 2016, 02:49

Tore, we know that the Germans do not used Tab Washers on the internal pipe flanges bolts but used Tab Washers on all pipe flanges bolts that penetrated the pressure hull.

Do you think the Germans used Tab Washers on all the external pipe flanges outside the pressure hull or only on the pipe flanges that penetrated the pressure hull?

Simon.
I cannot remember for sure, but would be inclined to think they would use tabwashers or other locking devices on essential pipeflanges like fuel compensatingwater and ventducts.
Tore

tore · « **Reply #3214 on:** 01 Dec , 2016, 05:04 »

Karel.
You remembered right, in silent run mode the enginetelegraphs had switches on the controlbox in the controlroom enabling to disconnect the audible singnal system. In fact we used this system during night not to disturb sleeping crew under normal circumstances. Down below is an image of the control box which I picked from Dons Skizzenbook which I guess comes for sale next year.
Tore

Don Prince · « **Reply #3215 on:** 01 Dec , 2016, 15:21 »

Hello Mr. Tore,

While surface running there is an air inlet ventilation stack and an air outlet ventilation stack... I guess the inlet stack is on the Starboard side in back of the tower under the bridge deck, is that correct?

Regards,
Don_

SnakeDoc · « **Reply #3216 on:** 01 Dec , 2016, 15:55 »

Hi Don,

Quote from: Don Prince on 01 Dec , 2016, 15:21

While surface running there is an air inlet ventilation stack and an air outlet ventilation stack... I guess the inlet stack is on the Starboard side in back of the tower under the bridge deck, is that correct?

You are right, the ventilation inlet trunk is at starboard side, behind the conning tower, inside the conning tower casing, under the Wintergarten platform.

--
Regards
Maciek

tore · « **Reply #3217 on:** 02 Dec , 2016, 00:11 »

Don and Maciek.
The dieselair intake is as you said on stb side and the large airduct goes outside the pressurehull to the main dieselair hull inletvalve. In the engine room it splits in stb and port duct ending at the bordsides behind the engine towards the bilges. Surfaced in bad weather the seawater from the ducts gushed down to the bilges which was the purpose for the design. I once experienced on U 926 KNM Kya after a refit during a testdive we had a severe leakage on the dieselair intakevalve, filling up the whole duct to the hullvalve being shut. The effect was we went down like an elevator and we had to blow all the ballasttanks before we finally stopped at 117 meters.
Tore

NZSnowman · « **Reply #3218 on:** 02 Dec , 2016, 21:01 »

Hi Tore,

Any idea that valve 'b' could look like, on Plan 10 : Fuel Oil Compensating System?

http://www.uboatarchive.net/U-570/U-570Plate10.htm

PS. Don have you see any photo's of this valve?

Don Prince · « **Reply #3219 on:** 04 Dec , 2016, 19:13 »

Hi Simon,

I don't have a sure answer to your question... Only an unsure opinion - I have attached a photo as a possibility (Note I highlighted the valve in question). I believe the valves in question are a three way cock with a 'T" plug and a means to limit the valve to only 2 positions...

The image attached seems to qualify for the "b" valve going to FBT 4 port side because it is far enough ahead of the Q Tank. It looks to be low enough to fit into the scheme of things, and it has a means to limit the valve movement. There is a red metal stake that extends into the valve hand wheel spokes which will limit the valve selection... Hopefully Mr. Tore or Maciek will have a definitive answer to your question instead of my 'SWAG"...

Regards,
Don_

NZSnowman · « **Reply #3220 on:** 04 Dec , 2016, 21:55 »

Hi Don

From what I know valve 'b' is outside the Pressure Hull.

To me the valve in the picture look like a high pressure air valve.

It like you said we will need to wait for Tore or Maciek.

Simon

Don Prince · « **Reply #3221 on:** 05 Dec , 2016, 00:22 »

Hi Simon,

I believe you should wait for a response from Mr. Tore or Maciek... I was just thinking of a drawing in Skizzenbuch where a valve for the header tank or sea water selection was located at the bottom of the saddle tanks. If they had to change the selection, then the valve stem would need to come through the pressure hull to change from the fuel oil mode to the ballast mode.

Skizzenbuch -
"The compensating water pipes goes from the header tank to a small chamber (about 1.5 % of the tank volume) at the bottom of the tank, from this chamber a short pipe goes into the tank bottom and an equalizing pipe directly to the sea. The two connections are controlled by a double seated selector valve operated from the casing. The valve has only two positions, either to the fuel tank or direct to the sea. When in the fuel oil tank configuration the Kingstons are shut and the selector valve open to the fuel tank and thus shut to the sea."

Regards,
Don_

NZSnowman · « **Reply #3222 on:** 05 Dec , 2016, 00:47 »

Quote from: Don Prince on 05 Dec , 2016, 00:22

Hi Simon,

I believe you should wait for a response from Mr. Tore or Maciek... I was just thinking of a drawing in Skizzenbuch where a valve for the header tank or sea water selection was located at the bottom of the saddle tanks. If they had to change the selection, then the valve stem would need to come through the pressure hull to change from the fuel oil mode to the ballast mode.

Regards,
Don_

That very interesting! I had always presumed that the valve was under the deck and not in the saddle tank. I have even draw this valve under the deck in my 2-D drawing

Don, have you come across any diameter of the pipes of the Fuel Oil Compensating System? Tore and I talked about this a few years back, and guessed something about a diameter of 75 mm but I am worry if this is too big

Don Prince · « **Reply #3223 on:** 05 Dec , 2016, 01:13 »

Hi Simon,

I have no idea as to the pipe diameters... I only know from what I have learned from Mr. Tore and Maciek plus a little research on my own.

Hello Mr. Tore,

Down like an elevator aye! And the problem was caused just by water in the inlet stack and the inlet line? Was Kya equipped with the later Schnorchel where the inlet pipe went crossed-over to the diesel air trunk? If that was the case, then the diesel air trunk above the pressure hull could also get flooded and that extra weight increase would be huge???

Regards,
Don_

tore · « **Reply #3224 on:** 05 Dec , 2016, 02:26 »

Simon- Don.
Sorry being late in answering. We never or very seldom used the fuel mode of the saddle ballasttanks, as we operated the VIICs as Coastal submarines. Hence I have not a personal experience of operating same. Transfering a ballasttank into fuelconfigurating requires some preparation. Of course the ventducts have to be shut, the blowing pipe both HP air and exhaust has to be locked shut, but nevertheless the compensating water pipe is in place and in ballasttank configuration you have to take measures to prevent blowing air into the compensating system.
In the bottom of the external ballast/fuel tanks the compensating water is checked by a selectorvalve D on the plan 8 this valve has two positions either open directly to the bottom of the tank and shut to the sea (fuelmode) or (in ballast mode) via a recess in the tank ( to prevent possible oilspill) to the sea and shut to the tank. My rough sketch below might explain the idea.The selector valve sits on the top of the pipe in the tank like some of the fuel testingvalves but are operated from outside the pressurehull ( not in the controlroom). The system prevent, in ballast mode, that the compensating system don`t get higher pressures than the head of the compensating expansion tank in the towercasing regardless of the depth of the submarine and is not influenced by HP airblowing of the ballasttank. Tore

SnakeDoc · « **Reply #3225 on:** 05 Dec , 2016, 02:31 »

Quote from: Don Prince on 04 Dec , 2016, 19:13

The image attached seems to qualify for the "b" valve going to FBT 4 port side because it is far enough ahead of the Q Tank. It looks to be low enough to fit into the scheme of things, and it has a means to limit the valve movement. There is a red metal stake that extends into the valve hand wheel spokes which will limit the valve selection... Hopefully Mr. Tore or Maciek will have a definitive answer to your question instead of my 'SWAG"...

The red medal stake is the drive shaft of the FBT 4 flooding valve.

--
Regards
Maciek

Don Prince · « **Reply #3226 on:** 05 Dec , 2016, 12:54 »

Hi Maciek,

I believe you are not looking at the red metal stake that I was referring to...

Regards,
Don_

SnakeDoc · « **Reply #3227 on:** 05 Dec , 2016, 15:19 »

Hi Don,

Quote from: Don Prince on 05 Dec , 2016, 12:54

I believe you are not looking at the red metal stake that I was referring to...

Indeed, I was looking on wrong stake. However the element you are referring to is (in my opinion) the MBT 3 blowing line check-valve.

Note that this element is located at the (curved) top of MBT 3 (it is not pressure hull). If it would be stake for the selector valve in question, it had to penetrate MBT 3 walls two times (it would not be desired).

--
Regards
Maciek

Don Prince · « **Reply #3228 on:** 05 Dec , 2016, 15:55 »

Hi Maciek,

Your photo is much better than mine. However, I was thinking of something like this...

Regards,
Don_

NZSnowman · « **Reply #3229 on:** 05 Dec , 2016, 18:59 »

Quote from: Don Prince on 05 Dec , 2016, 15:55

Hi Maciek,

Your photo is much better than mine. However, I was thinking of something like this...

Regards,
Don_

From this viewpoint, the line look like its working its way up pressure hull.

NZSnowman · « **Reply #3230 on:** 05 Dec , 2016, 20:03 »

Quote from: tore on 05 Dec , 2016, 02:26

Simon- Don.
Sorry being late in answering. We never or very seldom used the fuel mode of the saddle ballasttanks, as we operated the VIICs as Coastal submarines. Hence I have not a personal experience of operating same. Transfering a ballasttank into fuelconfigurating requires some preparation. Of course the ventducts have to be shut, the blowing pipe both HP air and exhaust has to be locked shut, but nevertheless the compensating water pipe is in place and in ballasttank configuration you have to take measures to prevent blowing air into the compensating system.
In the bottom of the external ballast/fuel tanks the compensating water is checked by a selectorvalve D on the plan 8 this valve has two positions either open directly to the bottom of the tank and shut to the sea (fuelmode) or (in ballast mode) via a recess in the tank ( to prevent possible oilspill) to the sea and shut to the tank. My rough sketch below might explain the idea.The selector valve sits on the top of the pipe in the tank like some of the fuel testingvalves but are operated from outside the pressurehull ( not in the controlroom). The system prevent, in ballast mode, that the compensating system don`t get higher pressures than the head of the compensating expansion tank in the towercasing regardless of the depth of the submarine and is not influenced by HP airblowing of the ballasttank. Tore

Hi Tore, Don & Maciek.

Does this valve need to be in the saddle tanks?

If you place this valve under the deck and right next to the saddle tank this seem to me a have a few advantages than being within the saddle tank (Fig. 1). Can be easily accessible and easier for maintenance.

I also checked my U-boat plans and there an opening in the saddle tank between frame 38 & 39. You can see this opening on U-995 (Fig. 2) (It has been welded up in the photo). This is very likely the opening to the sea.

Figure 1.

Figure 2.

Don Prince · « **Reply #3231 on:** 05 Dec , 2016, 22:36 »

Hi Simon,

That all looks like a possibility... However, I am very concerned about conjecture at this point. I still can't understand the hand wheel gear driving a worm shaft that seems to go to a pipe. That makes no sense to me. To say the least, I'm very confused at this point about the selector valve for the saddle tanks...

Hello Mr. Tore,

While searching through my U-995 CD I found the drive shaft for the FBT 2 saddle tanks Kingston valves. I have attached the image.

Regards,
Don_

SnakeDoc · « **Reply #3232 on:** 06 Dec , 2016, 00:00 »

Hi Gentlemen,

Quote from: NZSnowman on 05 Dec , 2016, 18:59

Quote from: Don Prince on 05 Dec , 2016, 15:55

Your photo is much better than mine. However, I was thinking of something like this...

From this viewpoint, the line look like its working its way up pressure hull.

The HP line goes up and then to stb, to the blowing distributor.

Quote from: Don Prince on 05 Dec , 2016, 22:36

That all looks like a possibility... However, I am very concerned about conjecture at this point. I still can't understand the hand wheel gear driving a worm shaft that seems to go to a pipe. That makes no sense to me. To say the least, I'm very confused at this point about the selector valve for the saddle tanks...

This is not a worm gear. This is how the valve is constructed. I have attached the photo of another valve from the bow torpedo room and another from control room (FBT 4 hull blowing valve stb).

--
Regards
Maciek

Don Prince · « **Reply #3233 on:** 06 Dec , 2016, 00:52 »

Hi Maciek,

Thanks for the info about the valve... I was thinking of a mechanical hand wheel with a worm gear shaft. It looks like you are right about the valve in question, and it's attached to the upper area of MBT 3; I'm not sure where it goes? Perhaps to an air pressure gauge? That would be one means to know the pressure inside MBT 3 when blowing the tank... Is what looks to be a red spring latch just a reminder that they had better know what they are doing before changing the valve setting?

I'm still not sure where the selector valve is physically located for FBT 2 and 4; inside the saddle tanks or above and under the deck like Simon suggests? I guess I have a lot of questions... It seems the more I learn about the Type VII, then there is the more I don't know...

Regards,
Don_

SnakeDoc · « **Reply #3234 on:** 06 Dec , 2016, 01:38 »

Quote from: Don Prince on 06 Dec , 2016, 00:52

It looks like you are right about the valve in question, and it's attached to the upper area of MBT 3; I'm not sure where it goes? Perhaps to an air pressure gauge? That would be one means to know the pressure inside MBT 3 when blowing the tank...

This is line going to the blowing manifold. See the attached drawing (I marked the line with green color).

--
Regards
Maciek

Don Prince · « **Reply #3235 on:** 06 Dec , 2016, 01:53 »

Hi Maciek,

Great work... You convinced me that this line is for blowing MBT 3! It seems like such a small air line to blow such a huge ballast tank (MBT 3). Comparing the size of the blowing line to the size of the venting valves (2) for MBT 3 in the venting trunks... Since the blowing line is such a small diameter have you ever read as to how long it took to blow MBT 3 (even partially blow)?

With the differential in vent and blowing diameters, then diving time would be faster, and surfacing time would be much slower...

I see there are two blowing valves for MBT 3 Port and Starboard...

Regards,
Don_

SnakeDoc · « **Reply #3236 on:** 06 Dec , 2016, 02:16 »

Don,

Quote from: Don Prince on 06 Dec , 2016, 01:53

Great work... You convinced me that this line is for blowing MBT 3! It seems like such a small air line to blow such a huge ballast tank (MBT 3). Comparing the size of the blowing line to the size of the venting valves (2) for MBT 3 in the venting trunks...

The diameters of the blowing lines: internal 17 mm, external 20 mm.
As a point of interest, the regulating tanks and Q-tanks blowing lines diameters are: internal 22 mm, external 26 mm.

Quote from: Don Prince on 06 Dec , 2016, 01:53

Since the blowing line is such a small diameter have you ever read as to how long it took to blow MBT 3 (even partially blow)?

No, as I recall, I have never met such data. But knowing the flooding holes cross-area and blowing air pressure and amount, the time could be possible to estimate.
If I remember correctly, Mark has made such calculations.

Quote from: Don Prince on 06 Dec , 2016, 01:53

With the differential in vent and blowing diameters, then diving time would be faster, and surfacing time would be much slower...

I'm not sure if flooding cross-area did not have greater influence on blowing and flooding time than vent and blowing lines diamater.

Quote from: Don Prince on 06 Dec , 2016, 01:53

I see there are two blowing valves for MBT 3 Port and Starboard...

Yes, you are right. I was not able to locate stb valve. If both valves were located symmetrical, the stb one should be located near the aft diving plane operating station. But there are oxygen bottles on the deck. So I guess, that the stb valve is located near (under) the blowing distributor.

--
Regards
Maciek

tore · « **Reply #3237 on:** 06 Dec , 2016, 02:39 »

Simon.
I guess you are right in assuming the selectorvalve for the compensatingwater could be outside the saddletank.In spite of an extra pipe it is much simpler and eliminates the stuffingbox for the valvespindle. You suggestion for the valvecasing could be correct I enclose an image of a selector valve in the fuelsystem.
Tore

tore · « **Reply #3238 on:** 06 Dec , 2016, 02:54 »

Don.
The image of your blowingvalve is indeed the port blowingvalve for MBT3. As you know you have a central bulkhead in MBT3, allthough the bulkhead is not pressure/watertight the tank still requires two blowingvalvs as well as two ventvalves.
What you assumed was a wormdrive is the housing for the checkvalve which is incorporated in the blowing valve casing. This is the classical ballasttank blowvalve and all the blowvalves have a non return/checkvalve.
Tore

tore · « **Reply #3239 on:** 06 Dec , 2016, 06:38 »

Simon.
Compensating water selector valve saddle fuel/MBT 2&4. May be an execution as below and possibly a removable T bar extension?
Tore

NZSnowman · « **Reply #3240 on:** 06 Dec , 2016, 10:33 »

Quote from: tore on 06 Dec , 2016, 06:38

Simon.
Compensating water selector valve saddle fuel/MBT 2&4. May be an execution as below and possibly a removable T bar extension?
Tore

This was how I had always imagined it was. Under the deck and with a removable ‘T’ handle. I got the idea a few years back after seeing the same valve in your other post.

I will try to do some drawing of my idea and post them this weekend.

Don Prince · « **Reply #3241 on:** 06 Dec , 2016, 13:51 »

Hello Mr. Tore and Simon,

I looked at the starboard side of U995 and the hole for the compensating water to the sea are questionable... I have attached the images...

Regards,
Don_

Don Prince · « **Reply #3242 on:** 06 Dec , 2016, 14:54 »

Hello Mr. Tore,

I have a very dumb question that is bugging me since this current discussion began... Please see the drawing and straighten me out again. What am I missing?

Kind regards,
Don_

tore · « **Reply #3243 on:** 07 Dec , 2016, 00:13 »

Don, It is not a dumb question and the arrangement of the two pipes is an assumption. The only answer I can give is the footvalve of the system is a double seated valve with two possible positions either to connect the fueltank with the header tank in the fuel configuration to provide compensating water or to put the ballasttank in connection with the sea. The only reason I can see for the latter configuration is to have a relief/safety arrangement for a possible blowing of the ballast tank with the Kingstons shut thus prevent overstressing the tank. Otherwise you are right in you statement about the fuelcontamination prevention of the sounding system during fuelling.

Tore

NZSnowman · « **Reply #3244 on:** 07 Dec , 2016, 00:41 »

Tore, does the opening to the sea needs to be at the bottom of the saddletank?

In the photo below you can very clearly see a pipe opening (Blue arrow).

Don Prince · « **Reply #3245 on:** 07 Dec , 2016, 01:01 »

Hello Mr. tore,

I have a NAVPERS 16160 manual for the US Fleet Type Submarine and they have Ballast and Water Compensated RFO tanks as well. They have a valve inside the pressure hull that channels the water to a pipe that extends to the bottom of the tanks.

I have a problem with Skizzenbuch pages 81 through 83 where I'm not sure if it is accurate? I possibly need to change the drawings on all 3 pages and the text on page 83.

"The compensating water pipes goes from the header tank to a small chamber (about 1.5 % of the tank volume) at the bottom of the tank, from this chamber a short pipe goes into the tank bottom and an equalizing pipe directly to the sea. The two connections are controlled by a double seated selector valve operated from the casing. The valve has only two positions, either to the fuel tank or direct to the sea. When in the fuel oil tank configuration the Kingstons are shut and the selector valve open to the fuel tank and thus shut to the sea (see the diagrams on page 78)."

1. Indicates a small chamber near the bottom of the tank
2. A short pipe that goes to the bottom of the saddle tank
3. A equalizer pipe directly to the sea
4. The two connections are controlled by a double sealed selector valve from the casing
Plan 10 shows the selector valves (b), but there is no indication that the valve is internal to any tank. Thus the thought of the selector valve being under the deck casing, but I'm not sure...
I did a guess drawing with 1 pipe and the selector valve under the deck. The selector valve has 3 positions:
1. Off
2. Water to the tank
3. Test/water overboard
What do you think?

Don Prince · « **Reply #3246 on:** 07 Dec , 2016, 01:11 »

Hi Simon,

Could you please email me that photo without the arrows if you have one? I need a larger size for resolution if possible...

I pulled Skizzenbuch from my dropbox so I could make changes on pages 81 - 83 (I don't want my managing editor getting it yet)...

Regards,
Don_

tore · « **Reply #3247 on:** 07 Dec , 2016, 01:43 »

Don.
I Guess 4. ...... double sealed selectorvalve......is a misprint. I am not sure of the three positions of the selector valve 1. Off?
I guess you have only two positions either to the tank or to the sea.
Tore

Don Prince · « **Reply #3248 on:** 07 Dec , 2016, 02:01 »

Hello Mr. Tore,

OK, I changed the drawing...

Regards,
Don_

NZSnowman · « **Reply #3249 on:** 07 Dec , 2016, 02:11 »

Quote from: Don Prince on 07 Dec , 2016, 01:11

Hi Simon,

Could you please email me that photo without the arrows if you have one? I need a larger size for resolution if possible...

I pulled Skizzenbuch from my dropbox so I could make changes on pages 81 - 83 (I don't want my managing editor getting it yet)...

Regards,
Don_

Sorry Don, that is the only one I have

I got it from Siara (http://models.rokket.biz/index.php?action=profile;u=44) many years ago. I never seen it in a book or anywhere on the Internet.

tore · « **Reply #3250 on:** 07 Dec , 2016, 02:17 »

Simon.
I don`t see any particular reason to have the outlet at the bottom of the tank, might be you have found a solution by your photo.
Tore

Don Prince · « **Reply #3251 on:** 07 Dec , 2016, 19:56 »

Hello Mr. Tore,

I uploaded Skizzenbuch back to dropbox. If at all possible would you review pages 81, 82, and 83 because I modified your drawings and updated the text to reflect the changes... Actually there was not that much to change.

Regards,
Don_

NZSnowman · « **Reply #3252 on:** 07 Dec , 2016, 21:26 »

Here are some early modelling of the valve.

Fig. 1. Top view. Images has been resized. Click to view original image.

Fig. 2. Port view. Images has been resized. Click to view original image.

Fig. 3. Images has been resized. Click to view original image.

Fig. 4. Images has been resized. Click to view original image.

Fig. 4a. Images has been resized. Click to view original image.

Fig. 5. Deck hatch closed. Images has been resized. Click to view original image.

Fig. 5a. Deck hatch open. Images has been resized. Click to view original image.

Fig. 5b. Deck hatch open. Images has been resized. Click to view original image.

Don Prince · « **Reply #3253 on:** 08 Dec , 2016, 00:05 »

Hello Mr. tore,

If I remember correctly, you said U-926 Kya had a damaged MBT 3 which was done by accident...

OL Hellmut Rehren was the CO who joined the Kriegsmarine back in 1939 and worked his way up the ranks until 1943 when he became a OL. He was given command of U-926 in February 1945 and had to surrender his 1st command on 9 May 1945. I'm willing to bet that he or his EO were NOT very happy about that prospect.

The type VII C has 12 HP storage canisters and it would be very simple to shut the Kingstons and the emergency vent valves and vent valves, and then blow MBT 3 while running on the surface to surrender with the hatches open. If the pressure of 16 bars from the 1st attempt didn't blow the end caps off the ballast tank (not likely), then recharging the HP canisters and the 2nd 16 bars surely would do the job...

Formula...

PV = PV

Canister pressure is 201 bars at 3.936 m³
MBT 3 volume is 47.75 m³ (Pressure would be = 16 bars) if all is blown into the tank.

Regards,
Don_

tore · « **Reply #3254 on:** 08 Dec , 2016, 01:19 »

Don.
I`ve checked Skizzen book page 81 thru 83 and have marked off my findings as per images below. I guess a misunderstanding has ocurred as to the gate valves in the MBT 2&4 ventingsystem. You don`t have both gatevalves and cumbersome blindflanges in the system, you have gatevalves instead of cumbersome blindflanges. As you know a gatevalve is almost an easy removable blindflange.
Tore

tore · « **Reply #3255 on:** 08 Dec , 2016, 02:22 »

Don.
Kya`s ex. U 926 structual damage. 12 Storage containers seems a lot, we had only 3 when I was onboard. I am a bit confused as to HP blowing of the storage container as you know the containers are not equipped with any HP airconnection and are simply a pressureproof container with lid like the ammocontainers. Anyhow Boyle Mariottes low is valid and Storage containers might be a confusion with the HP air flasks or airbottles as we say. 205 bar with an expansion to 10-25 bar makes a considerable volume increase, but a detail which is forgotten is the temperature drop according to Boyle Mariottes P1xV1/T1=P2xV2/T2. Such a temperaturdrop during a long blowingtime might cause freezing of the blowing valve which is one of the reasons the main blowing panel in the controlroom has an emergency blowing valve shortcutting the main blowing valve in case of freezing.
Back to U 226 and the structural damage. it is a long story which I might revert to if any interest, but the conclusion was, in late April/ early May grossadmiral Dønitz ordered all the operational uboats to Norwegian ports as Norway was going to be the center for the German submarine high command for the last desperate fight. More than 100 boats arrived causing a capacity problem at the surrender and the Allied forces decided to remove these boats to Scotland sailing the boats by the german crew. The operation was named Pledge, and a Norwegian naval submarine delegation took part in an investigation as to which Uboats were fit for the crossing to Scotland. I guess all but 11 were fit and amongst those 11 were , the U-995, U-926 and U 1202 which later were reconditioned and operated by the Royal Norwegian navy. The whole story is long and last year I wrote an article on the event in the main newspaper in Oslo, I have translated same to English.
Tore

tore · « **Reply #3256 on:** 08 Dec , 2016, 02:50 »

Simon.
It`s a delight to see you are back with you amazing drawings, as many times we have to improvise and assume as no reliable images exist. I am still in doubt of the selector valve, not the position outside the tank. The selectorvalve is a double seated valve and we have such a selector valve in the trimsystem placed in the controlroom. It might be this valve is closer to the prevously indicated.
Tore

NZSnowman · « **Reply #3257 on:** 08 Dec , 2016, 11:20 »

Hi All

Yesterday I think I found the valve and piping on U-534.

Don Prince · « **Reply #3258 on:** 08 Dec , 2016, 11:47 »

Hi Simon,

Those photos seem to verify that the selector valve was below the deck... Great investigation and find! It's amazing that some of the tanks internal surfaces are not rusted like the internal pressure hull. Perhaps they stayed in tact and were not flooded after all those years at the bottom of the sea.

Hmmm... I just noticed that the kingstons are shut. That would mean they were in a fuel oil storage configuration. That could account for the better condition of the tank's internals.

Mr. Tore,

Just for my own personal knowledge, what is the difference between a selector valve, a sealed selector valve, and a double sealed selector valve?

Regards,
Don_

Don Prince · « **Reply #3259 on:** 08 Dec , 2016, 12:10 »

Hello Mr. Tore,

I made the suggested changes to pages 82 and 83 and uploaded the Skizzenbuch update to dropbox. Thank you for reviewing the text...

Regards,
Don_

tore · « **Reply #3260 on:** 09 Dec , 2016, 00:38 »

Don.
A double seated valve is probably not a precise name as f.i. a gatevalve can be double seated using both side of the "gate". However in this specific case of a compensator selector valve it means a valve having two seatings which can only be put in either-or position. The image below is a double seated valve having one inlet and two outlet. For smaller pipes such a "valve" would be a three way cock, in the case of the valve below, the valve has to be operated to the end stops, up or down like the selector trimvalve in the controlroom shown below. I don`t think there is any mentioning of a double sealed valve in this connection, I guess this might be a misunderstanding.
Tore

Don Prince · « **Reply #3261 on:** 09 Dec , 2016, 02:06 »

Hello Mr. Tore,

What is this lever for located near the GW Diesel engine on U-995?

Regards,
Don_

tore · « **Reply #3262 on:** 09 Dec , 2016, 05:05 »

Don.
As you know U 995 is equipped with Krupp Germaniawerft main engines. Contrary to the MAN engines the GW engines were only partly supercharged in the upper outputs by a mechanical driven Roots blower. The blower is driven from the camshaft assembly in the aft end of the main engine and switched in at a given output and revs by a doublecone clutch. The handle you refer to is the handle for same. Simultaneously to engaging the blower is the shutting of the natural aspirating air inlets for each cylinder in order to accommodate the common airduct for the supercharging air to the cylinders. This is done by rotating the natural aspirating inlet valves by the same handle. May be the image below is of some help.
Tore

Don Prince · « **Reply #3263 on:** 09 Dec , 2016, 23:11 »

Hello Mr. Tore,

It looks like there is no interlock for reversing since U-995's GW Diesel engine is non-reversing, and the handle is different from the drawing Plan 30 with the reversing interlock.

It looks as if the handle is down (Aspirater mode), and raised up (Supercharged mode) is that correct...

Regards,
Don_

tore · « **Reply #3264 on:** 10 Dec , 2016, 00:13 »

Don.
As you know the plate 30 as published is from the manual of U 570 later HMS Graph, comissioned in 1941, and as such shows the GW engine in a direct reversible execution. The later non reversible GW engines had most of the maneuvring gear removed and simplified so the plate 30 is not relevant to every detail for the U 995. I believe the lever for the roots blower was raised in an engaged position.
Tore

NZSnowman · « **Reply #3265 on:** 10 Dec , 2016, 15:42 »

Tore, I noted on the early Type VIIC's, there are small bass labels next to the deck hatches. Most likely identifying the hatches. Do you think they carried on this practice with the late war U-boat?

NZSnowman · « **Reply #3266 on:** 10 Dec , 2016, 18:54 »

Quote from: tore on 08 Dec , 2016, 02:50

Simon.
It`s a delight to see you are back with you amazing drawings, as many times we have to improvise and assume as no reliable images exist. I am still in doubt of the selector valve, not the position outside the tank. The selectorvalve is a double seated valve and we have such a selector valve in the trimsystem placed in the controlroom. It might be this valve is closer to the prevously indicated.
Tore

Hi Tore

Here are the new drawings of the Selector valve (Figure 1). I cannot get it to fix in the space available on the post side of the main ballast and reserve fuel oil tank 2

Looking that the pictures of U-534, my original Selector valve (Figure 2) looks more correct. I might leave the Selector valve till later, until we get better pictures or after I add the saddle tanks to my model, to see how much real space there is.

Simon

Fig. 1. New Selector valve. (Images has been resized. Click to view original image).

Fig. 1a. New Selector valve. (Images has been resized. Click to view original image).

Fig. 2. Original Selector valve. (Images has been resized. Click to view original image).

Fig. 2a. Original Selector valve. (Images has been resized. Click to view original image).

tore · « **Reply #3267 on:** 11 Dec , 2016, 01:05 »

Simon.
Your selector valve fig two is probably correct for an inboard fuelvalve but for an outboard valve your fig 1 would probably be better with a few modification. The stuffingbox should be a bit different. Below I have tried to indicate my idea. The threaded part of the valvespindle should be on the top of the spindle whereas the spindle should be without threads in the valvehousing where the packing materiel is located. I can not remember any brassplates for identification on the later VIICs, in the latter part of the war the Germans hardly used any brass.
Tore

NZSnowman · « **Reply #3268 on:** 11 Dec , 2016, 11:47 »

Tore, the hull valves ('h') for the low pressure exhaust gas for main ballast and reserve fuel oil tank 2 & 4 http://www.uboatarchive.net/U-570/U-570Plate16.htm

Which valve do you think is best figure 1 or 2?

Figure 1.

Figure 2.

NZSnowman · « **Reply #3269 on:** 11 Dec , 2016, 11:47 »

Quote from: tore on 11 Dec , 2016, 01:05

Simon.
Your selector valve fig two is probably correct for an inboard fuelvalve but for an outboard valve your fig 1 would probably be better with a few modification. The stuffingbox should be a bit different. Below I have tried to indicate my idea. The threaded part of the valvespindle should be on the top of the spindle whereas the spindle should be without threads in the valvehousing where the packing materiel is located. I can not remember any brassplates for identification on the later VIICs, in the latter part of the war the Germans hardly used any brass.
Tore

Hi Tore,

Thanks for the information on the stuffingbox, I have always wonder about this detail. Below is the updated drawing.

Image has been resized. Click to view original image.

tore · « **Reply #3270 on:** 11 Dec , 2016, 13:05 »

Simon.
I Guess your figure 2 would be the appropriate, just remember not to have any threads on the valvespindle going through the stuffingbox.
Tore

NZSnowman · « **Reply #3271 on:** 11 Dec , 2016, 14:14 »

Quote from: tore on 11 Dec , 2016, 13:05

Simon.
I Guess your figure 2 would be the appropriate, just remember not to have any threads on the valvespindle going through the stuffingbox.
Tore

It’s not perfect, but it came out much better than I thought it would. Hard to improve the model until we get some better photos or a diagram of valve.

Image has been resized. Click to view original image.

Image has been resized. Click to view original image.

Image has been resized. Click to view original image.

NZSnowman · « **Reply #3272 on:** 11 Dec , 2016, 14:32 »

Tore, according to the Kriegsmarine Color Codes for piping, bunkers, cells, tanks and pumps & the Design Studies - Type IXC, valves were marked with the same color code as the piping. Do you think the outboard valve handle were painted or was it a waste of time?

tore · « **Reply #3273 on:** 11 Dec , 2016, 14:38 »

Simon. Looks fine, but might be you should make the flange bolts a bit shorter, the protruding threaded part outside the flange is of no use and make the dismantling more cumbersome than necessary.
Tore

NZSnowman · « **Reply #3274 on:** 11 Dec , 2016, 15:18 »

Quote from: tore on 11 Dec , 2016, 14:38

Simon. Looks fine, but might be you shold make the flange bolts a bit shorter, the protruding threaded part outside the flange is of no use and make the dismantling more cumbersome than necessary.
Tore

Thanks, with update

tore · « **Reply #3275 on:** 11 Dec , 2016, 23:00 »

Simon.
As far as I remember I don`t think the outbard valves had any colour code.
Tore

Don Prince · « **Reply #3276 on:** 12 Dec , 2016, 14:23 »

Hello Mr. Tore and Simon,

Is this the general idea behind the water compensation valve... My $0.02..

Regards,
Don_

tore · « **Reply #3277 on:** 13 Dec , 2016, 01:08 »

Simon, Don and others.
I woke up this night realising I have been conducive to a massive sabotage of the VIIC construction and am urging to come to a rescue.

The simple design of the compensating valve having an outlet under the casingdeck would probably act as a modest vent for the fuel ballasttanks 2 and 4 when shutting the valve to the compensatingtank and simultaneously open the ballasttank to the atmosphere while surfaced. My previouse (but not so elegant

) arrangement having the outlet by a second pipe down to the bottom of the saddletank in contact with the sea, prevented such venting. I like the idea of the compensating watervalve outside the saddletank, but I guess we have to have a second pipe down to a seawater connection at the bottom of the tank thus maintaining the ballast tank pressure while surfaced. The system has to be intergrated in the ballasttank by having a connection to the sea at the bottom of the tank in order to keep the ballasttank pressure. The seapressure at the bottom of the tank while surfaced would do this just as the open Kingstons are doing. I am sorry about this and as many times before I am afraid we probably have to find a new solution by the small expansion tank having seaconnection in the bottom of the tank. Does anybody have an image of the small bottom expasiontank?
Tore

Don Prince · « **Reply #3278 on:** 13 Dec , 2016, 02:12 »

Hello Mr. Tore,

I'm staying up so we can discuss the compensation system... Plan 13 for the GW Diesel engine and the water circulation system seems to indicate that the cooling water:

1. First the cooling water goes to the exhaust muffler.
2. Then the cooling water looks to have some vents to allow the water to go to the sea. I assume that don't want non-circulation water in the muffler because that would not cool the muffler. Therefore some of the cooling water must escape from the muffler.
3. Then the remaining cooling water goes to the header tank under the winter garden.

At this point we have cooling water in the header tank under pressure because the flow volume exceeds the leakage volume through the mufflers.

On Plate 10 we see where the cooling water is distributed to all the internal and external fuel oil tanks.

1. I see no problem if all of the tanks are in the fuel oil compensating mode because none of the tanks are open to atmospheric pressure and the cooling water system is closed.
2. If the 4 saddle tank compensation valves had a 3 position "OFF" then that would eliminate opening the water compensation system to the atmosphere.
3. The 2nd position on the 4 saddle tank compensation valve would be for "Testing" the water pressure and flow of the compensating water.

This solution would only require 1 compensating water pipe in the saddle tanks... What do you think?

Regards,
Don_

Don Prince · « **Reply #3279 on:** 13 Dec , 2016, 02:38 »

Hello Mr. tore,

Back to the valve above the saddle tank.

1. In the water compensation mode - the line is not open to the atmosphere but from the header tank to the saddle tank (Closed system).
2. Saddle tanks not in the water compensation mode - the valve has the saddle tank pipe shut (Closed system), and the valve has the header tank water flowing from the 2nd valve pipe to the sea...

If the water pressure from the diesel engine is not adequate to allow the drainage from the 4 saddle tank valves and maintain adequate water pressure to the internal tanks, then we would need an "Off" position on the water compensation valves under the deck.

Regards,
Don_

tore · « **Reply #3280 on:** 13 Dec , 2016, 03:21 »

Don.
I see your point of view, but my problem is if you look at the compensator water plan, the headertank outlet for the compensating water to the compensatigsystem is at the bottom of the headertank (no pipe up in the tank) and if the supply pipe to the saddletanks in the ballast configuration goes direct to the sea you`ll drain the headertank in surfaced position..
Tore

Don Prince · « **Reply #3281 on:** 13 Dec , 2016, 03:43 »

Plan 10

Let's discuss Plan 10

Don Prince · « **Reply #3282 on:** 13 Dec , 2016, 03:52 »

The inlet pipe is up in the header tank...

Don Prince · « **Reply #3283 on:** 13 Dec , 2016, 03:57 »

If the surface position will drain the header tank, then the 4 water compensation valves need to have an "OFF" position....

tore · « **Reply #3284 on:** 13 Dec , 2016, 07:38 »

Don do you ever sleep?

I am convinced we shall eventually find a good solution within our free design, however as we are looking for a solution which should be as close as possible to the real design we would have to use the resources available. The only reliable material I have at hand, as I explained previously we did not use the system, is plan 10 and a report on the system made by RN after an examination of U 570 later HMS Graph. An extract is below as well as plan 10. To me it seems obvious that the selectorvalve is a double seated valve ( not a cock) having three connections (positions): 1. from the compensating headertank. 2. compensating water to the bottom of the fueltank and 3. to the sea. It is only possible to select either 2 or 3. This was behind the rather un-elegant two pipe solution I proposed in the beginning.
I welcome any other solution within the basic infos available.
Tore

Don Prince · « **Reply #3285 on:** 13 Dec , 2016, 07:50 »

Hello Mr. Tore,

Where did that text come from?

Regards,
Don_

tore · « **Reply #3286 on:** 13 Dec , 2016, 09:06 »

Don.
From www. uboat archive.netU-570/British report.
Tore

Don Prince · « **Reply #3287 on:** 13 Dec , 2016, 10:57 »

Hello Mr. Tore,

How does this look?

Regards,
Don_

tore · « **Reply #3288 on:** 13 Dec , 2016, 12:02 »

Don.
This was my idea from the beginning, but we are not able to locate the expansion tank and the access to the sea.
My idea about the headertank is below.
Tore

NZSnowman · « **Reply #3289 on:** 13 Dec , 2016, 12:20 »

Quote from: tore on 13 Dec , 2016, 12:02

we are not able to locate the expansion tank and the access to the sea...

From C.B. 4318 report "The tanks are build of light plating..."

I rechecked my drive photos of U-1021 and U-352 and I cannot found kind structure in these areas. The tanks must be the first thing to rot away at the bottom of the ocean

I will keep looking.

Simon

NZSnowman · « **Reply #3290 on:** 13 Dec , 2016, 12:41 »

Quote from: tore on 13 Dec , 2016, 09:06

Don.
From www. uboat archive.netU-570/British report.
Tore

Hi Don & Tore

I never thought about looking at this report for pipe dimensions. I have always estimated the pipe dimensions by plans and photographs. I was just flipping through the report and notice on page 40 "The diameter of the ventilation pipes leading into the ship from the conning tower fairwater is approximately 9 - 3/4"." which is 247 mm. I just checked my 3-D model and I had estimated this pipe dimensions as 246 mm

Sorry about the inaccuracy of my model I will fixs this and will do better next time

This can give us confidence that we are heading in the right direction to workout how a U-boat works and is constructed!

NZSnowman · « **Reply #3291 on:** 13 Dec , 2016, 13:35 »

Quote from: NZSnowman on 13 Dec , 2016, 12:41

Quote from: tore on 13 Dec , 2016, 09:06

Don.
From www. uboat archive.netU-570/British report.
Tore

Hi Don & Tore

I never thought about looking at this report for pipe dimensions. I have always estimated the pipe dimensions by plans and photographs. I was just flipping through the report and notice on page 40 "The diameter of the ventilation pipes leading into the ship from the conning tower fairwater is approximately 9 - 3/4"." which is 247 mm. I just checked my 3-D model and I had estimated this pipe dimensions as 246 mm Sorry about the inaccuracy of my model I will fixs this and will do better next time

This can give us confidence that we are heading in the right direction to workout how a U-boat works and is constructed!

I found two more measurements in the report.

The diameter of the opening of the vent valves of Fuel-Ballast Tank No's 2 & 4, U-570 was 401 mm, I had estimated 385 mm (4% error).
The diameter of Engine air induction pipe on U-570 was 546 mm I had estimated at 502 mm (8% error).

NZSnowman · « **Reply #3292 on:** 13 Dec , 2016, 15:37 »

Tore & Don,

I think I found the expansion tank

Couldn't the small round shape at the very bottom of the saddle tank which is also right next the compensating pipe and the kingstons be the expansion tank??

It has a smaller diameter pipe coming out of it (its been cut in half but you can see it above and heading forward to the compensating valve).

Images has been resized. Click to view original image

NZSnowman · « **Reply #3293 on:** 13 Dec , 2016, 15:55 »

Maciek & Don, have you seen any size measurements for the high pressure gas bottles?

I also found these pictures of U-106 high pressure gas bottles

Don Prince · « **Reply #3294 on:** 13 Dec , 2016, 17:57 »

Hello Mr. Tore,

I updated pages 81, 82, and 83 text and I modified the 6 drawings to match with our latest discussions about the header tank water compensating system. I uploaded the latest version of skizzenbuch into dropbox. If you have the time would you please review what I have done and let me know if anything is not correct, or needs some changes to those 3 pages.

I was a little worried that my Schiffer managing editing would look for the files which I removed from dropbox... So I stayed up over night changing the drawings and struggling with the text. Then I had to redo the text files (schiffer specific files), update section 1 of skizzenbuch, re-join the 6 PDF files, and add the new drawings to the image folder, and finally upload all the files back to dropbox...

Just another day in paradise!

Good night to all,
Regards,
Don_

tore · « **Reply #3295 on:** 13 Dec , 2016, 23:36 »

Simon.
I guess the assumed image of the expansion tank of the IXC cutaway is probably the echosounder, I have previously been fooled by this image.
Tore

NZSnowman · « **Reply #3296 on:** 13 Dec , 2016, 23:54 »

Quote from: tore on 13 Dec , 2016, 23:36

Simon.
I guess the assumed image of the expansion tank of the IXC cutaway is probably the echosounder, I have previously been fooled by this image.
Tore

What make you think its the echosounder?

tore · « **Reply #3297 on:** 14 Dec , 2016, 00:08 »

Simon.
I found a description in some documents a few years back when I was looking for the expansion tank, unfortunately I do not remember the name of the source.
Tore

Don Prince · « **Reply #3298 on:** 14 Dec , 2016, 13:31 »

Hi Simon,

This is a modern echo sounder used by fishermen... Look familiar?

Regards,
Don_

tore · « **Reply #3299 on:** 14 Dec , 2016, 13:50 »

Don, you found the echosounder! On a type IXC it is probably a good place to put it as shown on the cutaway image, a similar place in the saddletank on the VIIC would be wrong. Keep looking for a small expansion tank and a seaconnection in the saddletanks of a VIIC.
Tore

NZSnowman · « **Reply #3300 on:** 14 Dec , 2016, 15:08 »

Quote from: NZSnowman on 13 Dec , 2016, 15:55

Maciek & Don, have you seen any size measurements for the high pressure gas bottles?

I also found these pictures of U-106 high pressure gas bottles

Estimating off the U-Boat plans the measurement are.

Bottle width: Average 458 mm, SD = 21 mm, n = 9.
Bottle length Type IX: Average 3779 mm, SD = 17 mm, n = 3.
Bottle length Type VIIC’s: Average 2492 mm, SD = 20 mm, n = 4.

Don Prince · « **Reply #3301 on:** 14 Dec , 2016, 16:58 »

Hello Mr. Tore,

Echolot info taken from the German Type VIIC training manual...

"Each device consists of: transmitter, receiver and amplifier. The shallow depth sounding device works noiselessly, while the deep depth device sends sound impulses which are audible. Both devices are powered by the AC shallow and deep depth echo sounding converter located in the E-motor room.

The deep depth sounding device has three transmitters and three receivers which are mounted in the keel. The shallow depth sounding device has one transmitter and one receiver. Both are mounted on bottom of the hull, on the port side, near the munitions magazine."

Regards,
Don_

tore · « **Reply #3302 on:** 15 Dec , 2016, 00:38 »

Don.
I should have remembered the position, but I don`t, in spite of sleeping almost on the top of it for 3 years.

My bunk, light blue, and the echosounder, red dot on the image below.
Tore

Don Prince · « **Reply #3303 on:** 15 Dec , 2016, 01:38 »

Hello Mr. Tore,

I had got a copy of the book which was in German about 5 or 6 years ago and struggled with the translation. I Faxed each page to Captain Jerry Mason of the uboatarchive.net and he had Maciek to translate the book and it's on Captain Jerry's website. It took me several hours to find where I got the information in the first place. Besides getting help from you about U-Boats, I need to start documenting where I got the info so I can find it again... I don't have all that experience like you do in your head, and there is no one else around with the knowledge and who actually lived in the Type VII C U-Boat.

Kind regards,
Don_

tore · « **Reply #3304 on:** 15 Dec , 2016, 02:27 »

Don.
The funny part of it is when we did a schnorcheling test in 1953 being 28 days submerged towards Greenland, the echosounder and good drafts with sounding contours was one of the major navigation instruments at that time.
Tore

SnakeDoc · « **Reply #3305 on:** 15 Dec , 2016, 14:26 »

Hi Simon,

Quote from: NZSnowman on 13 Dec , 2016, 15:55

Maciek & Don, have you seen any size measurements for the high pressure gas bottles?

All high pressure air flask at type VIIC U-Boats have following dimensions:
capacity: 325 l
length: 2650 mm
diameter: 450 mm
Dehnung: 12% (it translates to lengthening but I'm not sure what it can mean)

so your estimation is very accurate.

Quote from: NZSnowman on 14 Dec , 2016, 15:08

Estimating off the U-Boat plans the measurement are.
Bottle width: Average 458 mm, SD = 21 mm, n = 9.
Bottle length Type VIIC’s: Average 2492 mm, SD = 20 mm, n = 4.

--
Regards
Maciek

SnakeDoc · « **Reply #3306 on:** 15 Dec , 2016, 14:58 »

Hi Simon,

Quote from: NZSnowman on 13 Dec , 2016, 23:54

Quote from: tore on 13 Dec , 2016, 23:36
Simon.
I guess the assumed image of the expansion tank of the IXC cutaway is probably the echosounder, I have previously been fooled by this image.
Tore

What make you think its the echosounder?

In the book "Die Sonaranlagen der deutschen U-Boote" by Eberhard Rössler there is a description of the Echolot (Echosounder), which says that three sonic transmitters were located at port side, at the height of the Diesel engine room (just behind the bulkhead between control room and Diesel engine room).
On the photo attached by Simon we can see (if I'm not mistaken) the Diesel engine room, looking aft. In my opinion, the marked element is the most aft of the three sonic senders.

Note, that at the bottom of the opposite fuel tank, this element does not exist (if it would be expansion tank, it had to be there).

--
Regards
Maciek

SnakeDoc · « **Reply #3307 on:** 15 Dec , 2016, 15:07 »

Quote from: tore on 15 Dec , 2016, 00:38

Don.
I should have remembered the position, but I don`t, in spite of sleeping almost on the top of it for 3 years. My bunk, light blue, and the echosounder, red dot on the image below.
Tore

On page 429 of the Skizzenbuch there is visible location of the ultrasonic transducers.

--
Regards
Maciek

SnakeDoc · « **Reply #3308 on:** 15 Dec , 2016, 15:44 »

Quote from: SnakeDoc on 15 Dec , 2016, 14:58

Quote from: NZSnowman on 13 Dec , 2016, 23:54
Quote from: tore on 13 Dec , 2016, 23:36
Simon.
I guess the assumed image of the expansion tank of the IXC cutaway is probably the echosounder, I have previously been fooled by this image.
Tore

What make you think its the echosounder?

In the book "Die Sonaranlagen der deutschen U-Boote" by Eberhard Rössler there is a description of the Echolot (Echosounder), which says that three sonic transmitters were located at port side, at the height of the Diesel engine room (just behind the bulkhead between control room and Diesel engine room).
On the photo attached by Simon we can see (if I'm not mistaken) the Diesel engine room, looking aft. In my opinion, the marked element is the most aft of the three sonic senders.

I have attached the view of the bulkhead between Diesel engine room and control room (looking forward). The other (middle) sonic sender is visible there.

--
Regards
Maciek

SnakeDoc · « **Reply #3309 on:** 15 Dec , 2016, 16:29 »

Gentlemen,

regarding the expansion tank, reading the description of the ballast and fuel oil tanks in the German documents, I have found the following fragment:

Quote

Für Tauchbunker 2 und 4, Bb und Stb bei Betrieb als Tauchzellen.
Je 1 Sicherheitsrohr. Ist der Druckwasserschalter zu, stellt das Druckwasserrohr von Restwasser der Tauchzelle über Druckwassserschalter nach außenbords das Sicherheitsrohr dar.

Bei Betrieb als Treibölbunker ist ein Druckausgleich über die Druckwasserleitung bei offenem Druckwasserschalter möglich. Zur Vermeidung von Ölspuren ist die Druckwasserleitung in den Tauchbunkern in einen abgeschlossenen Raum zwischen zwei Spanten geführt. Verbunden ist dieser Raum mit dem Bunker durch ein gebogenes Übertrittsrohr, an diesen höchster Stelle ein Entölungsrohr angeschlossen ist.

I would translate it as follows (however please correct me if something is wrong):

Quote

For tanks 2 and 4, port and stb, used as ballast tanks.
Each tank is fitted with safety tube. When the pressurized cooling (compensating) water selection cock is closed, the residual water in the ballast tank overflows through the selection cock and safety tube overboard to the sea (my note: I guess - but I can be mistaken - that this description refers to the surfaced condition, when the pressurized cooling water is fed to the blown ballast tank).

When operating as fuel oil tank and when selection cock is opened, the pressure is equalized through the pressurized cooling (compensating) water system. To avoid the trail of the fuel oil, the pressurized cooling (compensating) water piping in the tank is enclosed in the space between two frames. This space is connected with the tank by means of the curved pipe (my note: maybe U-shaped pipe?). At the top of this curved pipe the de-oiling tube (my note: fuel oil venting/sounding/testing pipe?) is connected.

Maybe it somehow helps in further researches of the expansion tank.

--
Regards
Maciek

Don Prince · « **Reply #3310 on:** 15 Dec , 2016, 23:03 »

Hi Maciek,

That information could be interpreted is several ways... While running on the surface in the ballast mode:

1. The selector valve is in the Ballast configuration
2. The selector valve compensating water to the Ballast tank is shut
3. The selector valve now sends the compensating water to the Expansion tank at the bottom of the Ballast tank.
4. The small tube (Safety Tube) from the expansion tank is connected to the sea.

The "REPORT ON U-570 - H.M.S. GRAPH" on page 64 states...

They refer to the header tank under the tower as an expansion tank, and they also refer to a small tank at the bottom of each FBT (ballast tank) as an expansion tank. However, we refer to the tank under the winter garden as the header tank. Now their sentence makes sense...

"The expansion tank is always in open connection with the sea and thus the fuel tanks are always equalized and the only compensating water pressure which can be applied is due to the head of water in the expansion tank (Header Tank). This arrangement is necessary where direct blows are fitted and avoids the possibility of straining the tanks due to high pressure. The tanks are built of light plating and are tested to 15 lb. per sq. in."

Drawing attached.

Regards,
Don_

tore · « **Reply #3311 on:** 17 Dec , 2016, 07:40 »

Based on the info we have right now I have tried to put up a sketch showing my assumtion of the ballast/ fueltank compensating system. The small "expansion" box of thin sheetmetal in the saddletank bottom is located between two frame lenghts remains the image documentation and I assume the fuel "drain" from the expansion box is connected to the testcock system under the casingdeck. The outlets under the casing deck shown on Simons image could possibly be the outlets from the sample funnels in the system.
Tore

Don Prince · « **Reply #3312 on:** 17 Dec , 2016, 12:17 »

Hello Mr. Tore,

The British report on U-570 states... "The expansion tank is always in open connection to the sea..." In your drawing; If you are running in the ballast mode and submerged, then it looks like there is a possibility of having HP air entering the water compensating system with the small tube through the compensation tank at the bottom of the ballast tank when blowing the ballast.

I agree that the pipe in Simon's photo is most likely connected to the collector funnel on Plan 8a...

Regards,
Don_

tore · « **Reply #3313 on:** 17 Dec , 2016, 12:38 »

Don, if you follow the blue line on the image showing the ballast configuration you`ll see the ballasttank is in direct connection with the sea.
Tore

Don Prince · « **Reply #3314 on:** 17 Dec , 2016, 12:44 »

The "compensation water box" in your drawing... Is that the expansion tank at rhe bottom of the ballast tank? Why would it ever have fuel oil at the top?

Don_

Don Prince · « **Reply #3315 on:** 17 Dec , 2016, 13:03 »

By having the expansion tank pipe connected to the fuel oil venting pipe... As soon as the tank is full of fuel oil, then the fuel oil will enter the expansion tank during refueling?

Regards,
Don_

Don Prince · « **Reply #3316 on:** 17 Dec , 2016, 13:25 »

Yes, the blue line through the selector valve does have the expansion tank connected to the sea in the fuel bunker configuration. However, in the Ballast tank configuration the expansion tank is not connected to the sea other than through the open kingstons...

Regards,
Don_

tore · « **Reply #3317 on:** 17 Dec , 2016, 15:23 »

Don.
I guess we have a misunderstanding. On the image below I have marked a violet 1 for the ballast tank configuration, the selectorvalve is shut to the headertank and open to the sea. Seawater flows by a seapipe to the double seated selector valve and then to the small "expansion" tank, further by the bended (inverted U) pipe (shut drain cock) from the "expansion" tank into the ballasttank which then is in connection with the sea, thus acting as as "safety" line, relieving a possible excessive pressure in the ballast tank if the Kingstons are shut.
In the red circle marked fig 2 you have the system in fuelconfiguration having the selector valve shut to the sea and open to the headertank, thus suppling compensating water at a pressure(head) from the headertank thru the "expansion" tank into the fueltank.
Tore

Don Prince · « **Reply #3318 on:** 18 Dec , 2016, 01:57 »

Hello Mr. Tore,

I see where you are correct as usual... Could we compromise on the connection between the expansion tank and the fuel oil venting pipe. See my attached drawing, or explain the reason for that connection.

Regards,
Don_

Don Prince · « **Reply #3319 on:** 18 Dec , 2016, 02:09 »

Hello again Mr. Tore,

I was thinking (Bad Don_ again)... When the U-Boat is running on the surface with the saddle tanks in the fuel oil configuration, the internal and external pressure would be about 2 atmospheres. Water or fuel oil are not compressible. Let's say the U-Boat dives to 100 meters. Now, the external pressure is about 10 atmosphere and the saddle tank were sealed. So the internal pressure is somewhat less than the external pressure I think???

Therefore, the expansion tank is open to the sea via the header tank and it provides the path for the saddle tanks pressure to equalize. Since the liquids in the saddle tank are not compressible, perhaps the the expansion tank just applies the equalizing pressure (no expansion if any)...

Am I way wrong?

Regards,
Don_

tore · « **Reply #3320 on:** 18 Dec , 2016, 03:06 »

Don.
I guess you got it, and your fueloil venting ( draining) is workable, however the basics for my assumed design is the documentation available and Macieks reliable german source says: Verbunden ist dieser raum (expansiontank) mit dem bunker durch ein gebogenes Uebertrittsrohr an diesen hoeghster stelle ein entoelungsrohr angeschlossen ist. A bit freely translated: the expansionbox is connected to the fueloil bunkertank by a bended overflowpipe which has a "deoiling" (oildrain) pipeconnection at the highest point. Hence the drain/venting connection on the top of the inverted U pipe. Macieks source could of course relate to an older design of VIICs but I guess we better stick to what is documented. We still lack an original image showing the arrangement.
Tore

tore · « **Reply #3321 on:** 18 Dec , 2016, 03:26 »

Quote from: Don Prince on 18 Dec , 2016, 02:09

Hello again Mr. Tore,

I was thinking (Bad Don_ again)... When the U-Boat is running on the surface with the saddle tanks in the fuel oil configuration, the internal and external pressure would be about 2 atmospheres. Water or fuel oil are not compressible. Let's say the U-Boat dives to 100 meters. Now, the external pressure is about 10 atmosphere and the saddle tank were sealed. So the internal pressure is somewhat less than the external pressure I think???

Therefore, the expansion tank is open to the sea via the header tank and it provides the path for the saddle tanks pressure to equalize. Since the liquids in the saddle tank are not compressible, perhaps the the expansion tank just applies the equalizing pressure (no expansion if any)...

Am I way wrong?

Regards,
Don_

Don.
When you are on the surface in fuelconfiguration the saddle tanks are via the selectorvalve in direct connection with the headertank and shut to the sea, Kingstons shut. Hence the pressure in the saddletanks is only that which is obtain by the head, hight of the headertank, above the saddletanks as for a normal fueltank. Submerged the pressure difference between the saddletanks and the sea shall still be only that of the headertank hight as the headertank is then connected to the sea by its overflowpipe as well as the swan neck on the top of the headertank.
Tore

tore · « **Reply #3322 on:** 18 Dec , 2016, 05:25 »

iquote author=Don Prince link=topic=921.msg19928#msg19928 date=1482005001]
By having the expansion tank pipe connected to the fuel oil venting pipe... As soon as the tank is full of fuel oil, then the fuel oil will enter the expansion tank during refueling?

Regards,
Don_

When you are fueling, the fuel supply pressure forces the compensating water out of the saddletanks thru the compensating waterpipe, the compensating waterpipe ends about 10 cm above the residue water in the saddletanks. Close to the end of the fuelling you are all the time checking the compensating water outletflow from the testcock arrangement discussed. As soon as your testcock is showing fuel, you stop the filling. Possible fuelrests in the compensating watersystem is collected on the top of the inverted U pipe and "expansionbox" and can be drained later, when settled, by the test/draincocks. The headertank pipe ends in the bottom of the box,the possible fuel is on the top, thus you have a considerable, almost 1,5% of the tankvolume buffer to prevent fuel contamination of the compensating water system. This elaborate and complicated system has nothing to do with the environment people, they did not exist in the time of the VIICs, but at all cost to prevent an oilslick which might betray the submarines position.
Tore

Don Prince · « **Reply #3323 on:** 18 Dec , 2016, 17:37 »

Hello Mr. Tore,

You convinced me about the design of the expansion tank piping in the saddle tank... However, the actual function of the expansion tank is another question?

In the fuel oil configuration mode; the expansion tank seems to do nothing. When diving at depth equalization is done from the header tank through the expansion tank and to the venting pipe at the bottom of the saddle tank.

In the water ballast tank mode; if there was no expansion tank just a pipe at the bottom of the saddle tank, then in heavy seas the Kingstons could be exposed above the water line. This action removes the header tank back pressure and may flush the header tank. To eliminate the possibility of flushing the header tank, the expansion tank was added. Therefore in heavy seas where the Kingstons were above the water line, the pipe to the expansion tank is exposed, but the water in the expansion tank maintains the header tank back pressure.

Is this a bad conclusion?

Regards,
Don_

Don Prince · « **Reply #3324 on:** 19 Dec , 2016, 01:59 »

Hello Mr. Tore,

Does this rendition look OK?

Regards,
Don_

Don Prince · « **Reply #3325 on:** 19 Dec , 2016, 02:43 »

Hello Mr. Tore,

I uploaded Skizzenbuch to dropbox with the updated version of page 83 on water compensating system and the selector valve. When you have time would you please review page 83 and let me know in it is OK?

Regards,
Don_

tore · « **Reply #3326 on:** 19 Dec , 2016, 03:25 »

Don.
In fuelconfiguration the expansion box act as a possible oilspill buffer in the safety (relief) pipe to the sea, trapping possible fuel contaminated compensating water allowing to settle for a later drainage. As for your theory of while surfaced exposing the Kingstons to the surface in heavy wheather I guess it is a bit far fetched. A list exposing the Kingston to the surface would possibly cause battery acidspill and should be avoided and a possible short drainage of the headertank would not cause much of a trouble as surfaced you top up the tank by the dieselcoolingwater continuously. I guess you should only maintain the purpose of the expansion tank would be to prevent oilcontaminating of the compensating water to prevent possible oilspill regardless of the reason.
I discovered there is a text mistake in my sketch comp. water selector valve: The violet fig. 1 is fuelconfiguration and 2 is the ballast configuration as corrected on my image below.
Tore

tore · « **Reply #3327 on:** 19 Dec , 2016, 03:30 »

Don, I Guess so but may be you should add the selector valve in ballast position as well.
Tore

Quote from: Don Prince on 19 Dec , 2016, 01:59

Hello Mr. Tore,

Does this rendition look OK?

Regards,
Don_

SnakeDoc · « **Reply #3328 on:** 19 Dec , 2016, 05:11 »

Hi Gentlemen,

because we do not have detailed documentation of the fuel compensating system, I have started searching any pieces of information related with this subject.
In the attached pdf file I have transcribed the description of the fueling process (in German). It is interesting itself, but also it can provide some clues regarding the fuel system. I did not translate it because I didn't want to make mis-interpretation. You can easily copy text and use some online translators. We can also discuss some parts of text here, on the forum.

I have also attached the drawing with the external fuel tanks and ballast/fuel tanks at the type IXC/40 U-Boat. In my opinion, especially interesting is the drawing of the fuel tank (Treibolbunker), whose piping is similar to the installation given by Tore. On the other side, the arrangement of the ballast/fuel tank (Tauchbunker) is simpler than the corresponding, hypothetical piping of the ballast/fuel tank at type VIIC U-Boat.

--
Regards
Maciek

Don Prince · « **Reply #3329 on:** 19 Dec , 2016, 14:06 »

Hello Mr. Tore,

I believe I have missed something with regards to the selector valve... Does the selector valve have the header tank as its source and distributes compensating water to the saddle tank or to the sea (My drawing)? Or is the expansion tank the source and it is switched between the header tank or to the sea (Your drawing)?

1. In the ballast configuration you are shutting off all compensating water flow and the results would be an overflow at the header tank.

2. When surfacing, the ballast is blown to a point with compressed air, and then the diesel exhaust completes the blowing process. It looks like there is a possibility for the expansion tank to get blown as well?

I thought we originally wanted the compensating water either going to the saddle tanks or to the sea?

However, your selector valve configuration makes sense where the compensating water flow stops at the saddle tank in the RFO Configuration, and stops at the selector valve in the water ballast configuration.

Which is correct?

Regards,
Don_

tore · « **Reply #3330 on:** 19 Dec , 2016, 15:29 »

Don.
Your first question yes.
Your second question. As indicated on the image the pipe to the expansion box ends in the residue water in the ballasttank. When you are blowing the saddle ballasttank by exhaust you always look for the bubbles indicating the tank is empty. However you cannot empty the tank completly , there is always some residue water in the ballasttank as the Kingston opening is higher up than the end of the expansionbox pipe and as the pipe to the expansion box ends in this residuewater you would not exhaustblow the expansionbox. In ballast configuration the compesating watersystem is sealed off from the tank and is not involved in the ballast configuration.
Tore

Don Prince · « **Reply #3331 on:** 19 Dec , 2016, 16:16 »

Hello Mr. Tore,

Since Maciek has posted what looks to be a Type IX C/40 fuel oil tank (left) and ballast tank (right)... Should we reconsider the connection between the venting pipe and the compensating water pipe coming from the expansion tank? I would think the German U-Boat engineers would keep the same concept for both U-Boats...

One thing to note*

1. IX C fuel oil bunkers "a" could not be converted to a ballast tank
tanks FBT 2, FBT 3, FBT 4, R1, FBT 6, and FBT 7 could be fuel oil or water ballast

2. IX C/40 fuel bunkers "1a and 2a" could not be converted to a ballast tank
tanks FBT 3, FBT 4, R1, FBT 6, and FBT 7 could be fuel oil or water ballast

3. IX C/40 ballast tank design that could be converted to a fuel oil tank has the compensating water line going to the bottom of the tank, and the venting pipe 100 cm above the Kingston and no expansion tank.

Regards,
Don_

Don Prince · « **Reply #3332 on:** 19 Dec , 2016, 21:50 »

Hello Mr. Tore,

Wow, I apologize for being such a difficult student...

1. When the saddle tank is in the ballast mode; we have the compensating water line going through the selector valve to the sea through the saddle tank. Why do we need the line going through the saddle tank to the sea, the Kingstons are already open? It looks like we only need one water compensating line going into the saddle tank?

2. The expansion tank will capture fuel oil at the top during fueling. As long as the fuel oil is not forced into into the lower pipe in the expansion tank, then that's not a problem. later the fuel oil in the expansion tank will be forced back into the saddle tank by compensating water when the fuel oil is transferred internally.

3. I think the expansion tank is exactly that... during a hot day the fuel oil will expand and apply pressure on the compensating water and the water in the lines may overflow at the header tank. If the U-Boat dives to a depth where the sea water is much colder, then the fuel oil will condense and additional compensating water will enter the expansion tank from the header tank line. (Here in the US, they say to full up your auto tank in the morning - the gasoline is cooler, in the afternoon the gasoline is warmer and has expanded, so you get less for the dollar).

4. I have attached the drawing of the Type IX C/40 FBT selector valve, If it's the same valve in the Type VII C... Can you describe how it works?

Maciek, thanks for the drawing...

Regards,
Don_

tore · « **Reply #3333 on:** 20 Dec , 2016, 01:14 »

Q. 1. I guess you forgot the base for our assumptions which are confirmed German sources. Maciek quoted previously a German source: Je Sicherheitsrohr. Ist der Drueckwasserschalter zu, stelt das Drueckwasserrohr von restwasser der Tauchzelle ueber Drueckwasserschalter nach aussenbords das sicherheitsrohr dar.
Translated: Re safety pipe. If the selectorvalve is shut would the compensating pipe (in the tank) be connected via the selectorvalve to outboard ( the sea?) acting as a safety (relief) pipe. Hence to prevent venting, the outlet pipe takes the shortest way to the sea thru the tank as you would not have the pipe outside, .
Q.2. When the tank in the fuelconfiguration is recieving fuel, the compensatingwater is forced back via the selectorvalve to the headertank. As you know the filling of the tank is monitored by the check cocks above the compensating pipe end in the tank, particularly towards the end of the fuelling, which is stopped when fuel reach the testcock prior to the fuel reach the compensating watersystem ( expansionbox).
Q.3. If the tank is in fuelconfiguration, the expansion box is in contact with the sea via the headertank and the differential pressure sea/ tank at bottom of the tank would be equal to the weigth of the liquid (seawater) column up to the header tank. regardless the depth. The pressure in the expansionbox and tank might vary depending on the liquidcolumns temperature, salinity etc. but a differential pressure shall always persist.
Q.4. This icon of a selectorvalve is unknown to me, and is not shown on any VIIC plan. I am not familiar with the IXCs, but if you have a selector valve in the position shown on the IXC plan having the outlet to the sea, (outboard), on top of a ballasttank, the selectorvalve would act as a vent. Somehow this selectorvalve must prevent venting, I cannot tell how. In the VIIC system we have assumed a venting prevention by putting the outlet to the sea at the bottom of the tank mentioned above, not confirmed though. It could be worth while to check this item how it works as it would have been a better solution having the outlet under the casingdeck, avoiding the pipe thru the tank.
Tore

SnakeDoc · « **Reply #3334 on:** 20 Dec , 2016, 12:52 »

Hi Gentlemen,

Quote from: SnakeDoc on 19 Dec , 2016, 05:11

I have also attached the drawing with the external fuel tanks and ballast/fuel tanks at the type IXC/40 U-Boat. In my opinion, especially interesting is the drawing of the fuel tank (Treibolbunker), whose piping is similar to the installation given by Tore. On the other side, the arrangement of the ballast/fuel tank (Tauchbunker) is simpler than the corresponding, hypothetical piping of the ballast/fuel tank at type VIIC U-Boat.

To the drawing, I will add the related description from the Type IXC Design Study:

Quote

A compensating water system is used with all fuel carrying tanks with the exception of the auxiliary tanks. Pressure on the compensating system is through the medium of a head box in the superstructure. The compensating lines to the individual fuel ballast tanks run directly to the bottom of the tank while the line for the outboard normal fuel tanks (my note: that is Treibölbunker a) leads into the small salt water niche (1.5% of fuel tank's volume) in the bottom of the tank; a line then leads from the top of the niche to the bottom of the fuel tank. [...]. Test piping with an overboard discharge leads from the bottom of all the normal fuel tanks, and from a point approximately 4 inches above the top of the flood opening on the fuel ballast tanks (my note: that is Tauchbunker). These test lines are normally used as salt water discharge lines when fueling - not only to indicate when the tank is filled with oil - but mainly to prevent possible contamination of the compensating water lines with fuel oil. All piping runs external to the pressure hull.

--
Regards
Maciek

SnakeDoc · « **Reply #3335 on:** 20 Dec , 2016, 13:25 »

Quote from: tore on 20 Dec , 2016, 01:14

Q. 1. I guess you forgot the base for our assumptions which are confirmed German sources. Maciek qouted previously a German source: Je Sicherheitsrohr. Ist der Drueckwasserschalter zu, stelt das Drueckwasserrohr von restwasser der Tauchzelle ueber Drueckwasserschalter nach aussenbords das sicherheitsrohr dar.
Translated: Re safety pipe. If the selectorvalve is shut would the compensating pipe (in the tank) be connected via the selectorvalve to outboard ( the sea?) acting as a safety (relief) pipe. Hence to prevent venting, the outlet pipe takes the shortest way to the sea thru the tank as you would not have the pipe outside, .

These assumption are also confirmed by British report on HMS Graph (ex-U 570), quoted previously by Tore:

Quote

The compensating water pipes are led from the expansion tank (head tank in fact, my note) in the conning tower casing through double-seated valves to the small expansion tanks fitted at the bottoms of the fuel tanks. The double seated valves must be either in connection with the expansion tank (head tank in fact, my note) or with the sea. The expansion tank is always in open connection with the sea and thus the fuel tanks are always equalised and the only compensating water pressure which can be applied is that due to the head of water in the expansion tank (head tank in fact, my note). This arrangement is necessary where direct blows are fitted and avoids the possibility of straining the tanks due to high pressures.

and

Quote

The water passes down to the tank through a double-seated valve which admits water to the tank either from the expansion tank (head tank in fact, my note) or from the sea.

However British made some confusion, using the "expansion tank" term for the head tank in the conning tower as well as for expansion tank at the bottom of the fuel oil/ballast tank. I have made some annotations to point which tank is which.

Don, I would also think that German engineers would keep the same concept for both types of U-Boats, however there are clues that they wouldn't.

--
Regards
Maciek

Don Prince · « **Reply #3336 on:** 20 Dec , 2016, 18:54 »

Hello Mr. Tore and Maciek,

I would like this iteration of the expansion tank system to be the final change to Skizzenbuch on this subject.

1. I went back to Mr. Tore's latest drawing.
2. I re-drawn the selector valve in the Fuel Oil Mode and the Ballast Mode.
3. I got the expansion tank pipe below the Kingston's highest point (the pipe is always in the water).
4. In the Fuel Oil Mode the expansion tank is in connected to the header tank through the selector valve, and while submerges it is in contact to the sea at the header tank.
5. In the water Ballast Mode, I corrected the selector valve and Identified the Safety Pipe.

If I understand the function of the safety pipe in the Ballast mode; during a HP blow the ballast water is forced out though the open Kingstons, and into the expansion tank as well, and you don't want that thin metal tank damaged! So the connection at the selector valve to the safety pipe which drains to the sea provides the means for pressure relief. Excessive pressure from the HP Blow forced water into the expansion tank through the compensating water outlet pipe (backwards water flow)...

Gentlemen, If anything is not correct; text or the drawing, then please let me know!

Regards,
Don_

karel · « **Reply #3337 on:** 21 Dec , 2016, 03:42 »

Hello friends. Just wanted to leave a screenshot here of the game that we are building. Again, big thank you for all of you here for helping me to build this thing.

tore · « **Reply #3338 on:** 21 Dec , 2016, 05:41 »

Karel.
Amazing atmosphere. The handwheels of the exhaustblowing panel is a bit on the large side. When you are blowing the tanks by exhaustgas the tophatch is normally open and people are on the bridge. During daytime you`ll get a welcome faint glimse of daylight coming down to the hatch opening.
Tore

karel · « **Reply #3339 on:** 21 Dec , 2016, 06:58 »

Thank you Tore.

Yes, we had to exaggerate a little bit because of today's state of technology. Having bigger handwheels makes it more comfortable for a person to grab this object with motion controllers and also helps keeping physics a bit more stable. Game engine physics tend to go nuts with these kinds of interactions. Just to give better context. The game is going to be played on this virtial reality device https://www.youtube.com/watch?v=qYfNzhLXYGc&t=135s

As for daylight. This was another sacrifice we had to make. Virtiual reality game must run minimum at 90 frames per second in order to avoid jitter in the headset. This means that to keep the visual quality that we want, we have to cheat here and there. This includes all lighting which will be baked into the environment. This sadly means no realtime light, when i open the hatch i am not going to get sunlight. These are just sacrifices that we must take in order to make it able to run on current gaming PC. But years from now, down the road we can change all that when gaming PC will become more and more powerful.

tore · « **Reply #3340 on:** 21 Dec , 2016, 07:35 »

Karel.
Interesting problems. Anyhow operating an Uboat in the artic would never offer a sunlight down the hatch, only dim daylight, but nevertheless highly appreciated after being days submerged.
Tore

tore · « **Reply #3341 on:** 21 Dec , 2016, 08:24 »

Don.
I am afraid we have not yet achieved a complete confirmed arrangement of the saddle tank fuel arrangement. Maciek has provided a few interesting informations although I agree to his comments you cannot copy details from a IXC to a VIIC, I am tempted to discuss the details of the crosssection of the fuel/ballast arrangement on the imaged shown by Maciek. On the image below I have tried to show details which might be applicable for a VIIC.
The "oil drain" from the inverted U-tube might not go up to a drainvalve below the casing deck, we have no german confirmation of such arrangement, I guess the arrangement with a small swan-neck shown on the IXC cross sectiondrawing is possibly an appropriate alternative, simple and reliable. The possible oilcontamination is lead by a small swan neck pipe from the overflowpipe from the expansion box ascending and eventually merge with the fuel in the tanktop. A fuelling check is done with the standard fuel checking.
The expansion box arrangement, light blue on the sketch, could very well be used on the VIIC saddletanks as it matches the written descriptions.
The selector valve arrangement is a puzzle as the icons on the systemplans are not identical, the IXC plans have obviously another selectorvalve design allowing the valve to act as relief valve without venting the tank thus avoiding the long pipe down the sea. Our latter pipe with sea outlet has yet to be confirmed for the VIICs.
Hopefully somebody might come up with some info/images allowing us to have a confirmed arrangement for your Skizzenbuch, until the our assumption remain unconfirmed assumptions. Sorry about that.
Tore

Don Prince · « **Reply #3342 on:** 21 Dec , 2016, 14:51 »

Hello Mr. Tore,

I have been confused about the pipe going to the sea from the selector valve... After Maciek came up with the type IX tank configuration, I created a drawing and then deleted it because of our further discussions. However, I went back to my MS trash basket and restored the image.

This is the drawing... Do you think this could be the basis for a different approach?

Regards,
Don_

SnakeDoc · « **Reply #3343 on:** 21 Dec , 2016, 17:03 »

Hi Karel,

Quote from: karel on 21 Dec , 2016, 03:42

Hello friends. Just wanted to leave a screenshot here of the game that we are building. Again, big thank you for all of you here for helping me to build this thing.

Great work. However, if you want to model type VIIC U-Boat (not a museum boat in Laboe), you should pay attention to some modern modifications, for example the control room periscope. The current periscope in the U 995 control room is a post-war type ASR C/13 attack periscope, taken from U-Hai or U-Hecht.
And not only ocular box is replaced, whole tube, together with periscope head is from the attack periscope.
See the attached drawing.

The original ocular box can be visible on this photo (provided by Tore):
http://models.rokket.biz/index.php?topic=921.msg19664#msg19664

More details in this article.

--
Regards
Maciek

Don Prince · « **Reply #3344 on:** 21 Dec , 2016, 22:37 »

Hello Mr. Tore,

What do you think about this version of the saddle tank compensation system?

Regards,
Don_

tore · « **Reply #3345 on:** 22 Dec , 2016, 00:51 »

Don.
Some how I have trouble to post my mail, I`ll revert as soon as it is fixed.
Tore

Don Prince · « **Reply #3346 on:** 22 Dec , 2016, 01:43 »

Hello Mr. Tore,

Just an Idea... After reading the U-570 Report several times; here is my idea...

1. It works OK in the Fuel Oil Configuration.
2. In the ballast Configuration the selector valve is open to the sea. The valve is above sea level so the sea water only comes up to the sea level in the pipe in this mode. When the U-Boat is submerged, the expansion tank is equalized through the open selector valve...

Regards,
Don_

Don Prince · « **Reply #3347 on:** 22 Dec , 2016, 03:02 »

Hello Mr. Tore,

This is the full detail drawing...

Regards,
Don_

Don Prince · « **Reply #3348 on:** 22 Dec , 2016, 16:18 »

Hello Mr. Tore,

additional drawing...

Don Prince · « **Reply #3349 on:** 23 Dec , 2016, 04:25 »

Hello Mr. Tore,

When the ballast tanks are in the fuel oil configuration, would they open the residual valves for FBT2 to allow the pipe between the shut gate valves to flood?

Regards,
Don_

tore · « **Reply #3350 on:** 23 Dec , 2016, 07:32 »

Don.
I am happy being back.I am not sure I understand you idea 3 correctly. If you have an arrangement as on your sketch in ballast configuration having the ordinary double seated selector valve shut to the headertank and open to an outlet under the casing deck you are venting the tanks if the Kingstons are open. which means you are loosing almost 50M3 buoyancy and do not have sufficient surface draft. I agree you are in conformity with the text and documentation, but unfortunately with a lousy draft. Normally when you are operating an active submarine at sea you`ll have the Kingstons open and ready to dive. The only time this would work is if the Kingston are shut thus the documentation should have mention these restrictions to my opinion. We have then to assume a remark to the design : the selectorvalve in ballastcondition can be open to the sea only when the Kingstons are shut thus acting as a safety/relief connection to the sea. I am still in doubt if that is the correct arangement.
Tore

tore · « **Reply #3351 on:** 23 Dec , 2016, 07:50 »

Quote from: Don Prince on 23 Dec , 2016, 04:25

Hello Mr. Tore,

When the ballast tanks are in the fuel oil configuration, would they open the residual valves for FBT2 to allow the pipe between the shut gate valves to flood?

Regards,
Don_

Don.
The residue venting of fuel/ ballasttanks 2 have gatevalves pretty close to the ventpipe outlet from the tank. I assume these valves are shut in fuel configuration.
Tore

Don Prince · « **Reply #3352 on:** 23 Dec , 2016, 20:15 »

Hello Mr. Tore,

Referring to the attached drawing...

1. In order to establish the final air pressure inside the saddle tanks while on the surface; The diesel exhaust blowing pressure is 0.5 atmospheres above atmospheric pressure of 1.0 atu. Therefore, the saddle tank internal air pressure will be 1.5 atu after the exhaust blowing.

2. The water level inside the saddle tanks will be just above the top of the Kingston ports; the saddle tank's Kingston valves are open to the sea while the U-Boat is on the surface or submerged (water ballast configuration).

3. The air in the saddle tanks will remain captured in the saddle tanks until the vent valves located at the top of the saddle tanks are opened, then and only then will water level rise inside the saddle tanks while the U-Boat is on the surface.

4. It is established that the compensating water outlet pipe is positioned near the very bottom of the saddle tank and well below the standing water level inside the saddle tank. So, there is no means for the ballast tank air to escape from the saddle tank unless the saddle tank is vented.

5. If we compare the water pressure from the surface to the water level at the bottom of the saddle tank where the Kingstons are open to the sea, and then to a point outside the ballast tank at the same water level; the water pressure would be exactly the same.

6. Therefore, the water level inside the compensation pipe going to the selector valve which is open to the atmosphere would be at the sea level. This would be the water line established by the U-Boat's buoyancy (displacement) Vs the weight of the U-Boat.

This would be the same principle with the following test; if we took a water glass and drilled a hole through the bottom center and placed a straw through the hole until it lined up with the top edge of the glass, then we turn the water glass upside down and partially submerge it into a bath tub filled with water. The air in the glass would be slightly compressed as we forced the glass into the water, and the water level in the straw would match the water level in the bath tub. If we had a means of balancing the glass, then it's weight would establish the water line for the glass in the tub...

What do you think?

Kind regards,
Don_

tore · « **Reply #3353 on:** 24 Dec , 2016, 02:25 »

Don.
When the ballasttank is open to the sea, the seawaterlevel rises in the tank until the counterpressure of the air/exhaustgas is equal to that of the seapressure. When the system is in ballance, the pressure is the buoyancy pressure. When the ordinary vents are opened, the pressure is released and air /exhaustgas escapes from the ballasttank, allowing the seawater filling the tank.
When the selector valve outlet is open to the air as in the proposed system, the deplacement pressure is released as for normal venting. The only difference is, as the pipe for the selector valve ends in the tank residue water this water shall be forced out thru the selectorvalve outlet in stead of air/exhaustgas, followed by the seawater thru the Kingstons. When the water enters the tank it compresses the air/gas on the top leaving a small volume air/ exhaustgas in the top of the tank having the ambient seapressure when the system is in ballance. This means that when you release the deplacement pressure in the ballasttank thru the selectorvalve with open kingstons, seawater is filling the tank and you loose you deplacement buoyancy. According to Archimedes you are sinking with a small volume of air/ gas compressed on the tanktop. The only way to avoid this is to shut your kingstons which is not wise for an operational submarine.
Tore

Don Prince · « **Reply #3354 on:** 24 Dec , 2016, 03:17 »

Hello Mr. Tor,

If the expansion pipe outlet is below the water line in the saddle tank, the how can the tank vent through the selector valve to the atmosphere? There is NO path to vent the ballast tank???

Don Prince · « **Reply #3355 on:** 24 Dec , 2016, 03:28 »

Just like the Glass in the bath tub... the air pressure in the glass has not escaped, so the water pressure will force the water up the straw until it matches the tub level...

Don Prince · « **Reply #3356 on:** 24 Dec , 2016, 04:12 »

"When the selector valve outlet is open to the air as in the proposed system, the displacement pressure is released as for normal venting."

(1) The water from the sea through the open Kingstons goes up the pipe to sea level. The ambient pressure inside the saddle tank maintains the current water level in the ballast tank as set by the displacement Vs the weight of the U-Boat.

If the Kingstons were shut, then I would agree that the 1.5 Atu ambien air pressure would push the water up the pipe if the water column weight were less than the upward pressure differential. However, in this instance the ballast tank is being vented, but the U-Boat still maintains the same water line because we have not changed displacement with the shut Kingstons.

Don Prince · « **Reply #3357 on:** 24 Dec , 2016, 04:55 »

Hello Mr. Tor,

Would you please review the modified reply #3356

I'm staying up to work with you on this subject...

Kind regards,
Don_

Don Prince · « **Reply #3358 on:** 24 Dec , 2016, 06:09 »

Hello Mr. Tore,

Just for conversation... Lets say we closer the selector valve. Then we got a hose with a shut-off valve at one end, and place it at the deck height.

1. We then have a diver to take the other end of the hose down to the level of the internal compensating outlet pipe height. However, several feet away from the Kingston open port outside the U-Boat saddle tank. then we open the hose valve. I believe the water will be forced up the hose to sea level. correct?

2. Now, we have the diver to take the hose right up next to the Kingston open port outside the U-Boat at the same height and perform the exact same experiment. The results should be exactly the same. correct?

3. Finally, we have the diver to place the hose inside the ballast tank, and place it next to the compensating valve outlet. Then we open the hose valve and vent. I believe the external water pressure will push the water up to sea level and stop, just like the other experiments. The internal saddle tank air pressure of 1.5 atu has established the water level inside the saddle tank. The venting hose is filled with water from below the saddle tanks internal water line, and that water came from the sea.

Where am I wrong with this logic?

Kind regards,
Don_

tore · « **Reply #3359 on:** 24 Dec , 2016, 06:10 »

Don.
1. When the selectorvalve is open to the air (sea) the seawater enters the saddletank thru the kingstons as the displacement pressure is released, the tank is no longer a buoyancy tank as no counterpressure prevents the water to enter, if you put the selector outlet pipe down into the sea at the level of the kingstons you`ll have a counterpressure equal to the inletpressure and the system shall stabilize keeping the deplacementpressure and no air/ exhaustgas shall escape.
2 You assumption with shut Kingstons is correct appart from the 1,5 atu. The displacement pressure in the saddle tank would probably be less as the Kingston are about 2,2 meters below the sealevel at normal draft. The 1,5 atu is the limit for the exhaustgaspressure and relates to the mainengines backpressure limit rather than the saddletank deplacement pressure.
Tore

Don Prince · « **Reply #3360 on:** 24 Dec , 2016, 06:24 »

The displacement pressure has established a water level in the saddle tank. The compensating water outlet only sees the water pressure from the sea water below the ballast tank's established water level. And this pressure is dependent on depth..

tore · « **Reply #3361 on:** 24 Dec , 2016, 06:32 »

Quote from: Don Prince on 24 Dec , 2016, 03:17

Hello Mr. Tor,

If the expansion pipe outlet is below the water line in the saddle tank, the how can the tank vent through the selector valve to the atmosphere? There is NO path to vent the ballast tank???

If the tank has pressure, in this case deplacement pressure, this pressure forces the residue water thru the open selector valve, the air/gas remains on the top being compressed. As the residue water is drained the water entering the kingstons is partly following the residuewater up thru the selectoripe and overboard. The tankbuoyancy is gone and the submarine sits deeper in the water and eventually sinks (dives).
Tore

tore · « **Reply #3362 on:** 24 Dec , 2016, 07:06 »

Quote from: Don Prince on 24 Dec , 2016, 06:24

The displacement pressure has established a water level in the saddle tank. The compensating water outlet only sees the water pressure from the sea water below the ballast tank's established water level. And this pressure is dependent on depth..

Don, yes but when you release the displacement pressure via the selector valve there is no counter pressure and the water rises in the tank as you have lost the buoyancy. Loosing buoyancy means the boat sinks deeper and if all the saddletanks have lost their buoyancy it means you loose almost 50 tonnes. If you should do this operation on only one tank you create a surface list and upset the surface trim.
Tore

Don Prince · « **Reply #3363 on:** 24 Dec , 2016, 07:49 »

Hello Mr. Tore,

The best way to show my point is with a drawing...

We have two drinking glasses forced into a pool of water where both drinking glasses are partially flooded (we now have compressed air in the drinking glasses). We put two (2) glass tube in the water with my finger over the top end of each tube; one outside the drinking glass on the left, and one inside the drinking glass on the right.

Now, I allow the glass tubes to flood (this would be like opening the selector valve). The results would be that both tubes would flood up to the pool's water level. The water in the glass tubes came from the pool and there no connection or affect on the air pressure level inside either drinking glass air pressure area.

The water pool pressure acting inside both drinking glass enforces the water level in both scenario. Taking water from below the waterline in the drinking glass on the right changed nothing... With respect to the drinking glasses because the water came from the pool!

See my drawing!

When I inserted the two tubes into the pool of water, the pool's water level increased by the volume of both plugged water tubes. When I allowed the tubes to flood, then the pool water level decreased by the volume of water inside of both tubes.

Basically, when the selector valve is opened in the U-Boat, the water is coming from the sea because of the open Kingstons.

The U-Boat is not going to decrease the sea's water level when opening the selector valve and allowing the selector pipe to flood...

I hope this all makes sense???

Regards,
Don_

Don Prince · « **Reply #3364 on:** 24 Dec , 2016, 11:24 »

Hello Mr. tore,

Please review my updated reply #3363

Regards,
Don_

Don Prince · « **Reply #3365 on:** 24 Dec , 2016, 22:44 »

Merry Christmas to all, and to all a good night my friends...
Kind regards,
Don_

tore · « **Reply #3366 on:** 24 Dec , 2016, 23:40 »

Don
The same to you and all our VIIC friends. My wife and family think I am crazy sitting here with VIIC questions. Don I think your water glass gives a brilliant demonstration of the problem. Below I have modified your sketch a bit to demonstrate my thougths.
I guess the estimated deplacement pressure in the saddletank is appr. 0,22 atm. overpressure, which is appr. 2,2 m watercolumn. When you put a bended tube into the bottomwater in the tank leaving the other end of the tube in the atmosphere I guess the tankpressure push the water in the tube up to a pressure equilibrium when the watercolumn in the pipe is 2,2m above the sea surface, more or less as a watergauge where the watercolumn is showing the pressure in the tank.
If you place the selectorvalve at the top of the saddletank, I believe the outlet is less than 2,2 m above the seasurface. In that case the water in the tank is forced out of the tank allowing the seawater in thru the Kingstons.
May be this explains my theory a bit better.
Tore

tore · « **Reply #3367 on:** 25 Dec , 2016, 02:47 »

Don.
I guess I am going crazy ( just too old), my watergauge theory is all wrong, eliminating the pipe watercolumn in the sea. I must confess your system works and the matter is solved, thanks to your persistent stamina. The selectorvalve can have the outlet to the sea under the casingdeck and the outlet indicated on Simons image is most probably the selectorvalve outlets.
Sorry about the confusion.
Tore

NZSnowman · « **Reply #3368 on:** 25 Dec , 2016, 17:44 »

Tore, in the British Report on U-570 on page 36 on the H.P. Air Lines (http://www.uboatarchive.net/U-570/U-570BritishReport.htm). Do you think they still used copper on the late war U-Boats?

"2. The working pressure is 205 atms. and the air line is made of copper, external diameter 11/16 in., internal diameter 7/17 in."

Don Prince · « **Reply #3369 on:** 25 Dec , 2016, 21:55 »

Hello Mr. Tore,

Not a problem as Maciek would say... We all are getting older! However, I keep telling my wife Maureen that "I'm 17 going on 76"... I just don't recognize that old person when I look into a mirror!

Regards,
Don_

NZSnowman · « **Reply #3370 on:** 26 Dec , 2016, 12:13 »

This images has been resized. Click to view original image.

Hi Tore, Don & Maciek.

I know must of the openings above the exhaust maniford, but what is the Yellow opening?

White = Vent valves Opening - Main ballast/Reserve fuel oil tanks.
Orange = Main Exhaust Gas Blow Valve.
Green = HP air line.
Blue = Grease Distributors Opening.
Red = Exhaust Gas Flap Valve, Outboard Opening
Yellow = ??

SnakeDoc · « **Reply #3371 on:** 26 Dec , 2016, 15:12 »

Hi Simon

Quote from: NZSnowman on 26 Dec , 2016, 12:13

I know must of the openings above the exhaust maniford, but what is the Yellow opening?

White = Vent valves Opening - Main ballast/Reserve fuel oil tanks.
Orange = Main Exhaust Gas Blow Valve.
Green = HP air line.
Blue = Grease Distributors Opening.
Red = Exhaust Gas Flap Valve, Outboard Opening
Yellow = ??

The yellow opening is the HP line hull valve for the air bank 2 (two flasks above the diesel engine assembly patch).
I'm not sure about green opening - the valve handle looks like the valve used in the oxygen installation.

--
Regards
Maciek

Don Prince · « **Reply #3372 on:** 26 Dec , 2016, 16:05 »

Hello Maciek and Simon,

White - Is this the beveled gear assembly that activates the dual vent valves above the pressure hull; the ones that vents the residual trapped air in the main ballast/reserve fuel oil tanks (FBT 2) port and starboard side?

Regards,
Don_

SnakeDoc · « **Reply #3373 on:** 26 Dec , 2016, 16:10 »

Hi Don,

Quote from: Don Prince on 26 Dec , 2016, 16:05

White - Is this the beveled gear assembly that activates the dual vent valves above the pressure hull; the ones that vents the residual trapped air in the main ballast/reserve fuel oil tanks (FBT 2) port and starboard side?

Right you are, Don!

--
Regards
Maciek

Don Prince · « **Reply #3374 on:** 26 Dec , 2016, 16:29 »

Also here is a image of what I believe are the grease selectors in U-505 that didn't get covered with white paint like in U-995...

Regards,
Don_

SnakeDoc · « **Reply #3375 on:** 26 Dec , 2016, 16:33 »

Quote from: SnakeDoc on 26 Dec , 2016, 15:12

Quote from: NZSnowman on 26 Dec , 2016, 12:13
I know must of the openings above the exhaust maniford, but what is the Yellow opening?

White = Vent valves Opening - Main ballast/Reserve fuel oil tanks.
Orange = Main Exhaust Gas Blow Valve.
Green = HP air line.
Blue = Grease Distributors Opening.
Red = Exhaust Gas Flap Valve, Outboard Opening
Yellow = ??

The yellow opening is the HP line hull valve for the air bank 2 (two flasks above the diesel engine assembly patch).
I'm not sure about green opening - the valve handle looks like the valve used in the oxygen installation.

Regarding the green opening, I was not able to locate the similar valve at the port side - I'm almost sure there is only one valve.
Maybe it is the grease line for the FBT 2 residual air vent valve? Maybe the grease distributor nearby does not cover this one greasing point?
As far as I was able to trace both lines (from the unknown valve and grease distributor), they are going to grease hand-pump at the aft bulkhead of the diesel engine room.

--
Regards
Maciek

NZSnowman · « **Reply #3376 on:** 26 Dec , 2016, 20:03 »

Quote from: tore on 01 Dec , 2016, 03:53

Quote from: NZSnowman on 01 Dec , 2016, 02:49
Tore, we know that the Germans do not used Tab Washers on the internal pipe flanges bolts but used Tab Washers on all pipe flanges bolts that penetrated the pressure hull.

Do you think the Germans used Tab Washers on all the external pipe flanges outside the pressure hull or only on the pipe flanges that penetrated the pressure hull?
Simon.
I cannot remember for sure, but would be inclined to think they would use tabwashers or other locking devices on essential pipeflanges like fuel compensatingwater and ventducts.
Tore

and

Quote from: NZSnowman on 13 Dec , 2016, 13:35

Quote from: NZSnowman on 13 Dec , 2016, 12:41
Quote from: tore on 13 Dec , 2016, 09:06

Don.
From www. uboat archive.netU-570/British report.
Tore

Hi Don & Tore

I never thought about looking at this report for pipe dimensions. I have always estimated the pipe dimensions by plans and photographs. I was just flipping through the report and notice on page 40 "The diameter of the ventilation pipes leading into the ship from the conning tower fairwater is approximately 9 - 3/4"." which is 247 mm. I just checked my 3-D model and I had estimated this pipe dimensions as 246 mm Sorry about the inaccuracy of my model I will fixs this and will do better next time

This can give us confidence that we are heading in the right direction to workout how a U-boat works and is constructed!

I found two more measurements in the report.
The diameter of the opening of the vent valves of Fuel-Ballast Tank No's 2 & 4, U-570 was 401 mm, I had estimated 385 mm (4% error).
The diameter of Engine air induction pipe on U-570 was 546 mm I had estimated at 502 mm (8% error).

Today I fix the Engine air induction pipe diameter from 502 mm to 546 mm. So I added the tabwashers today

This images has been resized. Click to view original image.

NZSnowman · « **Reply #3377 on:** 27 Dec , 2016, 10:30 »

Quote from: SnakeDoc on 26 Dec , 2016, 16:33

Quote from: SnakeDoc on 26 Dec , 2016, 15:12

Quote from: NZSnowman on 26 Dec , 2016, 12:13
I know must of the openings above the exhaust maniford, but what is the Yellow opening?

White = Vent valves Opening - Main ballast/Reserve fuel oil tanks.
Orange = Main Exhaust Gas Blow Valve.
Green = HP air line.
Blue = Grease Distributors Opening.
Red = Exhaust Gas Flap Valve, Outboard Opening
Yellow = ??

The yellow opening is the HP line hull valve for the air bank 2 (two flasks above the diesel engine assembly patch).
I'm not sure about green opening - the valve handle looks like the valve used in the oxygen installation.

Regarding the green opening, I was not able to locate the similar valve at the port side - I'm almost sure there is only one valve.
Maybe it is the grease line for the FBT 2 residual air vent valve? Maybe the grease distributor nearby does not cover this one greasing point?
As far as I was able to trace both lines (from the unknown valve and grease distributor), they are going to grease hand-pump at the aft bulkhead of the diesel engine room.

--
Regards
Maciek

Thanks, Maciek.

tore · « **Reply #3378 on:** 30 Dec , 2016, 03:23 »

Simon.
Sorry I have been away during the xmas season and coming back I experienced my PC is not working properly. Anyhow I read your last question and shall try to sum up the answers as per my image below. As to the green valve it is obviously an oxygen valve, if you look at the oxygen plan you`ll see at the port aft end is a oxygenvalve marked off as an oxygen supply to " rescuedivers". I guess you shall find a similar installation in the aft controlroom stb side next to the aft hydraulic pump. In the engineroom the complete fillinggear is not shown, it could have been removed later. As the the system plan shows only the valve it could even possibly be that the complete installation was not installed originally, only the connection. I cannot remember this Equipment, and the manual do not mention any outboard connection at this point.
It might be I shall not be able to communicate for some days as my computer have to be checked and serviced,. it is still under guaranty.
Whishing everybody a happy New year and see you hopefully some time early next year!
Tore

SnakeDoc · « **Reply #3379 on:** 30 Dec , 2016, 08:19 »

Hi Tore,

it's good to hear from you again.

In my opinion, the valve in question can not be oxygen supply for the Drager rescue gears.
According to British Report on HMS Graph: (page 35)

Quote

To supply the oxygen bottles contained in the German equivalent of D.S.E.A. sets. This is fitted in the control room.

On the attached drawing I have marked the fitting for connecting the Drager sets and "d" valve (with red color).

There are three other valves marked with letter "d" (I have marked them with blue color), but they are for cutting-off the branching lines supplying the oxygen to ventilation intake duct.
In the Diesel engine room the valve "d" as well as pressure-gauges and regulating valves are located at the aft bulkhead, at stb side.
The oxygen lines are thinner than the line leading to the valve in question.

Moreover, the shape of the valve-handle cannot be used for determining the function of the valve: in diesel engine room, near the cooling water intake hull valves are similar valves (see attachment).

--
Regards
Maciek

NZSnowman · « **Reply #3380 on:** 01 Jan , 2017, 13:30 »

Re: Plate 13: Cooling-water system. http://www.uboatarchive.net/U-570/U-570Plate13.htm

► Valve 'o' - Drain valve should be on the bottom of the muffler?

► Valve 'n' - Vent valve should be on the top of the muffler?

► Does anyone know what Valve 'n' - Vent valve look like?

Re: Plate 10: Fuel oil compensating system http://www.uboatarchive.net/U-570/U-570Plate10.htm

► Does it matter where you take the hot water from the muffler for the Fuel Oil Compensating System?

NZSnowman · « **Reply #3381 on:** 02 Jan , 2017, 12:42 »

Quote from: NZSnowman on 13 Dec , 2016, 15:37

Tore & Don,

I think I found the expansion tank

Couldn't the small round shape at the very bottom of the saddle tank which is also right next the compensating pipe and the kingstons be the expansion tank??

It has a smaller diameter pipe coming out of it (its been cut in half but you can see it above and heading forward to the compensating valve).

Images has been resized. Click to view original image

The last time I thought I’d found it, but this time I have really found it this time, the expansion tank

Checkout this video https://www.youtube.com/watch?v=lWXyNY_MHfo

At 1:35 the driver swim along the casting and we see the two MB & RFO 2 & 4 control arms.

At 1:42 you get a clear view of the expansion tank with the compensating pipe.

At 1:44 you get a great overview of the tank and pipe.

This images has been resized. Click to view original image.

Don Prince · « **Reply #3382 on:** 02 Jan , 2017, 13:06 »

Hi Simon,

Possibly the location of the drain valves "o" Vs. the vent valve "n" may have something to do with the temperature of the water in the muffler... The hotter water will be on the top and the cooler water will be on the bottom. That's my take on the valve locations, until Mr. Tore comments...

Regards,
Don_

NZSnowman · « **Reply #3383 on:** 08 Jan , 2017, 15:03 »

I been checking more drive film.

Below is I believe the Fuel oil compensating system Pressure hull opening.

This images has been resized. Click to view original image.

NZSnowman · « **Reply #3384 on:** 09 Jan , 2017, 18:51 »

Hi Tore, Don & Maciek.

These are the best pictures of the Fuel oil compensating system & expansion tank, I have found so far.

To see fill size click https://www.flickr.com/photos/57740585@N04/32070927722/in/album-72157657431277710/

To see fill size click https://www.flickr.com/photos/57740585@N04/32181580976/in/album-72157657431277710/

To see fill size click https://www.flickr.com/photos/57740585@N04/32100839051/in/dateposted-public/

Don Prince · « **Reply #3385 on:** 11 Jan , 2017, 19:51 »

Hi Simon,

I have labeled items on one of your images as to what I believe they are... I am not sure about the rectangular opening in the lower area of Regulating Tank 2? Just for my own knowledge - How do you upload a huge file to this website and display a smaller image?

Regards,
Don_

SnakeDoc · « **Reply #3386 on:** 12 Jan , 2017, 03:43 »

Hi Don,

Quote from: Don Prince on 11 Jan , 2017, 19:51

I have labeled items on one of your images as to what I believe they are... I am not sure about the rectangular opening in the lower area of Regulating Tank 2?

The rectangular opening is the flood opening of the port negative buoyancy tank (Q-tank). See where it is located relative to the FuMO 30 antenna shaft. Both visible gears (you have marked one as FBT 4 flood valve and second as Q-tank flood valve) are in fact for the flood valves of the FBT 4 port.

Quote from: Don Prince on 11 Jan , 2017, 19:51

Just for my own knowledge - How do you upload a huge file to this website and display a smaller image?

Simon is using external image hosting service (flickr.com), after uploading the image he places the url to image in the message text between [ url ] [ /url ] tags.

--
Regards
Maciek

NZSnowman · « **Reply #3387 on:** 12 Jan , 2017, 11:23 »

Quote from: Don Prince on 11 Jan , 2017, 19:51

How do you upload a huge file to this website and display a smaller image?

Don, you can see all my photo's and pictures here https://www.flickr.com/photos/57740585@N04/albums

Don Prince · « **Reply #3388 on:** 12 Jan , 2017, 15:50 »

Hi Maciek and Simon,

Two images attached... The Q Tank section is very narrow and the Q Tank grill is square...

Regards,
Don_

SnakeDoc · « **Reply #3389 on:** 13 Jan , 2017, 01:00 »

Hi Don,

Quote from: Don Prince on 12 Jan , 2017, 15:50

Two images attached... The Q Tank section is very narrow and the Q Tank grill is square...

Indeed, U996 has square grill, however it can not mean anything, the grill shape could depend on the yard.
Look at the position of the radar antenna shaft and Q-tank position, they are almost at the same height.
Moreover, the driving shaft for the FBT is mounted horizontally, while for Q-Tank - aslant.

Look at the plating of the U 995 tanks. In the area of FBT you can see dented plates (because this tank is
not pressure-proof), while in the are of Q-tank (and regulating tanks) the plates are intact (because these
tanks are pressure-proof). Similarly with the wreck of U 352. I guess that we can look at the FBT interior now
because non-pressure-proof plating corroded, while the adjoining Q-tank is intact.

--
Regards
Maciek

NZSnowman · « **Reply #3390 on:** 13 Jan , 2017, 10:52 »

Quote from: SnakeDoc on 13 Jan , 2017, 01:00

Look at the plating of the U 995 tanks. In the area of FBT you can see dented plates (because this tank is
not pressure-proof), while in the are of Q-tank (and regulating tanks) the plates are intact (because these
tanks are pressure-proof). Similarly with the wreck of U 352. I guess that we can look at the FBT interior now
because non-pressure-proof plating corroded, while the adjoining Q-tank is intact.

Maciek, do you think the plating thickness is different between the two tanks?

SnakeDoc · « **Reply #3391 on:** 13 Jan , 2017, 11:36 »

Hi Simon,

Quote from: NZSnowman on 13 Jan , 2017, 10:52

Quote from: SnakeDoc on 13 Jan , 2017, 01:00
Look at the plating of the U 995 tanks. In the area of FBT you can see dented plates (because this tank is
not pressure-proof), while in the are of Q-tank (and regulating tanks) the plates are intact (because these
tanks are pressure-proof). Similarly with the wreck of U 352. I guess that we can look at the FBT interior now
because non-pressure-proof plating corroded, while the adjoining Q-tank is intact.

Maciek, do you think the plating thickness is different between the two tanks?

Yes, I'm sure that pressure-proof tanks plating was thicker than the non-pressure-proof tanks and outer shell plating.
Apart from the notes from the post above, I have the quotation from type IXC Design Study:

Quote

Outer shell plating is steel 42 (60000 psi tensile) specification KM 9104, except in the way of the variable tanks and negative tanks, which are specified to be of steel 52, (74000 psi tensile) specification KM 9104

The term variable tanks mean regulating tanks, and the term negative tanks mean Q-tanks.

--
Regards
Maciek

Don Prince · « **Reply #3392 on:** 13 Jan , 2017, 19:08 »

Hello Maciek and Simon,

Maciek is 100% correct about the different thickness of sheet metal on the saddle tanks:
1. R1, R2, and Q Tank outter sheet metal is 11.5 mm thick
2. FBT 2 and FBT 4 outter sheet metal is 6 mm thick
3. The internal walls of Q Tank are 13 mm thick

However, let's examine the sunken Type VII U-Boat in question...
1. I would say the missing sheet metal cover on the port side of FBT 4 and Q Tank was the result of a depth explosion and not the effects of salt water corrosion over time. The reason for my conclusion is there are no internal support structures; they seem to be torn-off from the pressure hull and saddle tank.
2. If you look aft, the saddle tank FBT 2 port side, it looks to be intact.
3. If you look at the attached drawing, Q Tank was designed to withstand internal pressure because of the aft concave and forward convex sides.
4. When the depth charge detonated; the port FBT 4 was ripped open and the forward wall of the Q Tank was designed for the opposite stress forces. Therefore, the port Q Tank was ripped open and exposed the mushroom valve actuating mechanism. Q Tank has 1 internal rib type support structure mid way in the tank, but I highly doubt that it would hold under such devastating pressure.
5. I conclude that both FBT 4 and Q-Tank on the port side were completely blown apart and the complete devastation stopped at the aft Q Tank internal wall which was designed to withstand a force in that direction.

Now as to that rectangle hole in question - I don't know? Did I go wrong on my conclusions as to what we see on this sunken U-Boat? Please advise...

Regards,
Don

PS - after looking at mt trusty steel ruler with inches on one side and mm on the other side; we're not talking about sheet metal. The 6 mm plate steel for FBT 2 and FBT 4 is a little under a 1/4 inch, and the 11.5 mm plate steel for R1, R2, and Q Tank is a little over 7/8 inch steel. This plating would have to be rolled to fit the framing. You are not going to bend that into place...

SnakeDoc · « **Reply #3393 on:** 14 Jan , 2017, 00:33 »

Hi,

maybe my plating consideration were going to far, however there are still issues of the flooding valves driving shafts orientation (which is horizontal for FBT 4) and their location relative to the conning tower (radar antena shaft).
In my opinion, the rectangular opening is located exactly where Q-tank is located.

--
Regards
Maciek

Don Prince · « **Reply #3394 on:** 14 Jan , 2017, 00:44 »

After doing a map of the damage... It looks like FBT 4 and Q Tank on the port side was completely blown apart when a depth charge detonated very close and below the open Kingstons on the port side and through the metal grill leading to and protecting Q Tank. The internal force blew the welded seams on FBT 4 and collapsed both the forward and aft walls of Q tank. It looks like the destruction went in as far as one vertical frame structure into R 2.

Regards,
Don_

SnakeDoc · « **Reply #3395 on:** 14 Jan , 2017, 02:36 »

Don,

on the wreck photo (in this post) with dashed line I have marked (approximately) the frame going through the Q-tank (which also crosses the radar antena shaft).
If the Q-tank was much forward and was blown away as you said, it had to be at the height of forward periscope (and this is not possible).

--
Regards
Maciek

SnakeDoc · « **Reply #3396 on:** 14 Jan , 2017, 02:44 »

Don,

Quote from: Don Prince on 14 Jan , 2017, 00:44

After doing a map of the damage... It looks like FBT 4 and Q Tank on the port side was completely blown apart when a depth charge detonated very close and below the open Kingstons on the port side and through the metal grill leading to and protecting Q Tank. The internal force blew the welded seams on FBT 4 and collapsed both the forward and aft walls of Q tank. It looks like the destruction went in as far as one vertical frame structure into R 2.

On your map of the damage, the four flood valves are operated by two driving shafts (valve mechanisms), that is two flaps are operated by one shaft and the other two are operated by second shaft.
On your map you have marked one mechanism for all four flaps.

--
Regards
Maciek

Don Prince · « **Reply #3397 on:** 14 Jan , 2017, 02:49 »

Hi Maciek,

I know that I am only guessing at this point... But since the destruction is into R 2 (I think?), then could that rectangular opening (if it is within R 2) be an inspection plate to permit servicing the Emergency Shut-Off Valve for venting MBT 3 within the air shaft? If you examine the previous image of U-995, they have a huge steel plate welded on what looks to be the outside area of this section...

I believe there would need to be a service plate to permit access for repairs to a damaged Emergency Shut-Off valve when in dry dock in a U-Boat pen...

Regards,
Don_

Don Prince · « **Reply #3398 on:** 14 Jan , 2017, 03:00 »

Hello Maciek,

Now I have a real problem... In my Skizzernbuch page 335 I have images of the drive shafts for the Saddle tank Kingstons and there is only one drive shaft for each tank (photos) of U-995... Am I wrong?

Regards,
Don_

SnakeDoc · « **Reply #3399 on:** 14 Jan , 2017, 03:07 »

Don,

the venting shaft of the MBT 3 is located behind the attack periscope and behind the conning tower. I have marked its approximately location on attached drawing (with green color).

However, I think you have right regarding the access opening to the emergency vent valve. I have found the photo (the shot from the movie) from opposite direction, when something like rectangular cover is visible (see attachment). If this is the access opening in the regulating tank, then the next rectangular hole is the flood valve of the Q-tank.

--
Regards
Maciek