Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Simon.
I guess you are right, I checked the KNM Kauras bedplate and the stiffening knees are all on the same level.
Tore

[TopherVIIC]

Simon -
I really love the galvanized metal texture you pulled off on the image above! Well Done!

[NZSnowman]

Tore, a couple of qections about the head tank.

• I can not remember the size you suggested this tank would be?
• Does this tank needs to have maximum height within the casting or can the tank be located anywhere within the casting?
• This the vent on top of the tank open to the sea?

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

[tore]

Simon
Head tank.
The head tank is not a storage tank but act like a head buffer where the cooling water from the outboard exhaustsystem enters the fuelcompensating system. I would guess a capacity of something between 25 max. 75 liters, it is situated in the old tower casing. It is in direct contact with the sea, while submerged, via a swan neck pipe on the top. It should give a head at the day/setlingtank up under the pressure hull in the engine room of about 2-3 meter.
The filling of the compensating system is done by the ME cooling waterpumps.
Tore

[NZSnowman]

Fuel oil compensating system

Hi Tore/Maciek

I am trying to track down this section of pipe that runs into FO Collecting Tank (Fig. 1.), where do you think I would found the valves f₁ and f₂ so I can location the starting postion of the pipe?


Fig. 1. http://www.uboatarchive.net/U-570Plate10.htm

[NZSnowman]

Simon.
Fuel drain.
The main fuel drain on the engine goes along the engine just about where the cylindercovers meets the cylinder block, it collect the spill from each cylindercover via funnels and leads to the forward of the engines joins the drain (yellow) from the knifefilter before it drain into the fuel draintank. It is no T piece where the fuel filter enters the maindrain, just a welded branch with threads for the connection.
Tore

Fuel drain lines (Violet-Red-Violet) into FO Collecting Tank

[tore]

Simon.
Looks fine . As you are aware of, the collecting tank has a few other connections, the venting and the suction pipe to the hand coolingwater pump indicated on the drawing below. I don`t know for sure but I believe it is a cast pipefitting on the top of the tank collecting all the four drainpipe connections.
Tore

[SnakeDoc]

Hi Simon

I am trying to track down this section of pipe that runs into FO Collecting Tank (Fig. 1.), where do you think I would found the valves f₁ and f₂ so I can location the starting postion of the pipe?

I was not able to locate this valve in Diesel Engine Room. However, it maybe helpful - similar valve for the internal fuel oil tank 2i is located in control room, near the helmsman station:



--
Regards
Maciek

[tore]

Simon.
Fuel collecting tank
Unfortunately I do not have pictures of all the components and I guess the systemsketch is not very complete. To start with the inboard venting and levelcontrol of fuel saddletanks 2 port and stb. see sketch below. If you look at the last photo of the fueloil system page on the U historia webside, you will see two L shaped handles up under the pressurehull on port and stb.side, these are the boardvalves for the inboard venting and levelcheck of no 2 fuel saddletanks. They are marked 7 on the photo and the pipe 8. I guess they have exchanged the L handles as the 2nd valve has the ball and the board valve not.  Hopefully you have better photos than me to localize the details.
Tore

[tore]

Simon.
As Maciek has been able to establish, the f1 and f2 valves is a double valve in one housing, it is an overpressure and  underpressure reliefvalve. I have not been able to localize it in the engineroom either. The confusing part of it is that the valve is located in the water compensating system which is with great effort designed so fueloil is not entering the system. In the fueltank, the compensatingpipe outlet is 10 cm below the ventingpipe and in a compensatingbox in order to prevent any fuel entering the system. The venting pipe is supposed to get a very small amount of fueloil when fuelling and the tank gets filled up . I believe the diagram I showed in my previous post is probably more reliable. I really don`t see why the drain from the reliefvalve in the seawater compensating system should end up in the fuelcollecting tank.
Tore

[NZSnowman]

Simon.
Fuel collecting tank
Unfortunately I do not have pictures of all the components and I guess the systemsketch is not very complete. To start with the inboard venting and levelcontrol of fuel saddletanks 2 port and stb. see sketch below. If you look at the last photo of the fueloil system page on the U historia webside, you will see two L shaped handles up under the pressurehull on port and stb.side, these are the boardvalves for the inboard venting and levelcheck of no 2 fuel saddletanks. They are marked 7 on the photo and the pipe 8. I guess they have exchanged the L handles as the 2nd valve has the ball and the board valve not.  Hopefully you have better photos than me to localize the details.
Tore

I was able to found the starboard funnel section     Have no idea the alignment and route the pipe takes once under to the floor, will have a educated guess on that

Tore, why have a open section within this system, was it so you can have a visual check? If so, why would you want to have a visual check?

[NZSnowman]

Simon.
Fuel collecting tank
Unfortunately I do not have pictures of all the components and I guess the systemsketch is not very complete. To start with the inboard venting and levelcontrol of fuel saddletanks 2 port and stb. see sketch below. If you look at the last photo of the fueloil system page on the U historia webside, you will see two L shaped handles up under the pressurehull on port and stb.side, these are the boardvalves for the inboard venting and levelcheck of no 2 fuel saddletanks. They are marked 7 on the photo and the pipe 8. I guess they have exchanged the L handles as the 2nd valve has the ball and the board valve not.  Hopefully you have better photos than me to localize the details.
Tore

Tore, on the port side there is a gage tank, what is it, what does it look like, what is it for?

[tore]

Simon.
I don`t believe the visual check is the main thing, you could better have a sigthglass. Generally a breach in the pipeline (funnel) is to eliminate a possible undesired syphoning effect in the system.
Tore 

[SnakeDoc]

Quite a different topic - I have just noticed, that in the aft part of the control room, where should be located the hand wheels for the head valves of the diesel engine air induction trunk, ventilation air intake and exhaust, one of these valves - ventilation air intake is missing:

http://www.kubische-panoramen.de/index.php?id_id=5378&p=i


It looks like after installing Schnorchel, the intake of the ventilation trunk was blanked. Moreover, the foot valve closing this trunk in the diesel engine room is still in place. I suppose, it was left to allow drain the trunk after accidental flooding.
Generally, such arrangements is like ventilation system on the "Schnorchel boats" - U-Boats type XXI and XXIII.




--
Regards
Maciek

[NZSnowman]

Simon.
I don`t believe the visual check is the main thing, you could better have a sigthglass. Generally a breach in the pipeline (funnel) is to eliminate a possible undesired syphoning effect in the system.
Tore

Thanks Tore! I learn something new every day