Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

An airvessel ( sometimes called windvessel) is only a " bulb" rigth after a pistonpump. It contains an air cushion which act like a buffer and equalizes the pressure fluctuations coming from a reciprocating machinery like a pistonpump. Nothing much, just a casted "blimp" migth be an airconnection on the top.
Tore

[tore]

Coolingwater pump.
The seacooling waterpump as far as I remember was placed fwd at the engine on port engine stb side fairly low down. On the posted picture I have indicated what I think is the pump.
Tore

[NZSnowman]

Coolingwater pump.
The seacooling waterpump as far as I remember was placed fwd at the engine on port engine stb side fairly low down. On the posted picture I have indicated what I think is the pump.
Tore

A big thanks Tore! I been looking for it all day, never thought it been could be on the engine 

[tore]

Seawaterchest.
Your nice drawing of the chest was in the beginning a bit confusing to me, it looked like the stb engine was connected directly to port and that port ended nowhere. Is it by any means you are able to make it clear that they are connected to two different outlets of the chest?
Tore   

[NZSnowman]

Tore, hope this makes it a little clear to understand. I think I now know that you are talking about, I just realise the Purple & Green lines on my drawing are the wrong way around  I will fix this tomorrow.

[NZSnowman]

Coolingwater pump.
The seacooling waterpump as far as I remember was placed fwd at the engine on port engine stb side fairly low down. On the posted picture I have indicated what I think is the pump.
Tore

Tore I also just found this 

U-Boat Type VIIC Manual - Page 120

Cooling water pump

The cooling water for cooling the engine lubricating oil cooler, the cylinder barrels, cylinder heads, exhaust valves and exhaust manifolds is fed by a double-piston pump. The drive of the pump takes place via the crank, which is propelled by gear wheel transmission from the crankshaft (Ratio 2:1).

[NZSnowman]

Here the correct layout. Could not wait till morning. Would hate to see U-1308 go to sea with bad piping

[tore]

Good thing you are at sleep.
The  redchecked pipe on your drawing is the seawater crossoverline, it ends on both sides in the same way, I believe you have indicated stb only. So may be you should add the two valves after the filter on port as well. You could perhaps add the standard weed airblow cleaning (both sides). From the seawater crossoverline are the suction side connection to both pistonpumps on the engines, and on stb side the the suction on electric driven ciculationpump, and handpump, see the posted picture marked green. I believe there is a mistake in the system drawing indicating no suctionconnection to the stb enginepump from the crossover.
Tore

[tore]

Luboil cooler seawaterpiping.
The pipes from the engine pumps goes to the valvechest ( there are two more pipes as well, forget about them now) and are distributed via your green and violet lines to the luboilcoolers. enters the luboilcoolers via a selectorvalve which means it can either enter the cooler or bypass it. Normal position is enter and the inlet connection to the outlet is shut. Hence it goes via the coolers and cools the oil before it goes to the engines a little heated  in order to prevent a coldshock to the engines.
Tore

[tore]

Luboilcooler 2
As far as I can see the luboilcooler bypass pipe seems to be without contact with the selectorvalve but disappear into the housing, is it any reason for that, I should believe it would be more like the red pipe indicated on the posted picture , you have in fact indicated the same by blue overunning the pipe. On my posted picture I have indicated on the crossover line where I believe the suctionconnections to the various pumps are.
Tore

[NZSnowman]

Luboilcooler 2
As far as I can see the luboilcooler bypass pipe seems to be without contact with the selectorvalve but disappear into the housing, is any reason for that, I should believe it would be more like the red pipe indicated on the posted picture , you have in fact indicated the same by blue overunning the pipe. On my posted picture I have indicated on the crossover line where I believe the suctionconnections to the various pumps are.
Tore

* Tore, Thanks for all the information!!!! It mean a lot that you are willing to help. They perhaps are little detail,  but to me, knowing that they were wrong would drive me mad!

* Yes, you are right about the luboilcooler bypass pipe seems to be without contact with the selectorvalve. I misread the system drawing yesterday, will fix this today

* Also really happy that you think the system drawing is wrong about indicating no suctionconnection to the stb enginepump from the crossover. Yesterday I spend about 8 hours looking at that system drawing trying to workout why the German Engineers had made no connection to the stb engine pump

* I will also do the miss port side sea inlet valve today. As a little tried last night to finish the drawing.

Low Pressure "weed airblow cleaning"

I was able to find the system drawing for this Also from the picture below, there look like two positions where the low pressure air entered the sea valve, this is correct?

Maciek, do you know this section of the Low Pressure system?

[tore]

I would believe the violet LP pipes are the rigth ones. You are awake and up, I am about to hit the sack in a heatwave 28 degrees C. All the snow is melting in the mountains which means the annual springflood is on its way, nothing serious though. Good luck with your work looking forward to see the results tomorrow.
Tore

[tore]

Seaweedcleaning.
I`m not sure if I misunderstood you. I think the the boardvalve (outer) opens  inward. In the event that seaweed obstruct the intake, the second valve (sluicevalve) is shut and LP air valve is opened allowing the air to the space between the sea and sluicevalve thereby blowing  the weed out. I don`t think there is any airconnection to the sluicevalve.
Tore

[tore]

Luboilreturnpipes.
I have been looking a bit more on the subject, see picture below. I think the strange bends on you drawings migth come from the relatively large returnpipe from the Roots blower (blue).The supplyline to the servomotor (green) is coming from underneath the deckplating and is fairly straigth. The servomotor returnpipe (yellow) is making a bend under the Roots blower casing for some reason unknown to me, but anyhow it has to connect to the larger pipe from the blower.
Tore

[tore]

Airvessel
As it seems to be an unknown item, I guess a picture would help when you are drawing same. It is not the airvessel on the engine attached coolingwaterpump but the airvessel on the piston trimpump.