Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Simon I think this is excellent. The piping which was not on the engine was the various shipyards jobs and module building was not very common in those days. There were deviations from yard to yard.
Tore

[tore]

Simon.
 When looking at your recent engine drawing I discovered a tiny detail on the fuelsupply pipe to the HP pumps which, with you liking of details, might be worth while to incorporate. On U 995 KNM Kaura the pipe between cylinder 7 and 8, is a draincock marked red on the port engine and only a cock connection shown on the stb engine. See the very bad picture below.
Tore

[NZSnowman]

Starting Air Control Supply and Starting Manifold added.


Scale: 1 pixel = 2.35 mm

[tore]

Simon, one step further to perfection.
Tore

[tore]

Fig. 1. Side view of new Air Starting supply piping.


Fig. 2. Top view of new Air Starting supply piping.


Fig. 3. New Air Starting supply piping under the decking. The layout is correct but the some of the piping and the

[tore]

Starting handles.
I guess you are about to draw the starting handles at the maneuvering stand. They are the same for port and stb engines, so the startinghandles are placed towards port and fuelhandles towards stb on both engines, which means that the linkage seen on the inboard side of the maneuvering stands are different (startinglinkage visible on the stb- and fuellinkage on the port engine). Another detail, all the handles are like double, the second handle is a lockingdevice and has to be pressed in in order to move the levers. .
Tore

[SnakeDoc]

Tore, I know, that fuel oil tanks (internal and external) were water-compensated. Were there a problem of mixing fuel oil and water (near the border between the layers of water and fuel)? I mean, if there created some kind of an emulsion?


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Thanks, regards
Maciek

[tore]

Maciek.
All the fueltanks were seawatercompensated except the settlingtank ( daytanks). There are several reason for that 1. What we call free surface effect has particularly a bad influence on a submarine with neutral buoyancy, and you want to avoid that by allways keeping as many tanks as possible  topped up. 2. As you consume fuel the submarines weight decreases and has to be compensated by increasing the ballast, eg. taking in seawater. The system is that you always have seawater under pressure lead to the bottom of the fueltank and have the fuellines outlet  on the top. The positive pressure under both surface and snorting is maintained by a header tank in the towercasing.
The only fueltanks which are not watercompensated are the two tanks above the engines, one act like a settling tank which means you fill it with fuel  and let the fuel settle and drain possible water while you are running the diesels from the other tank. We never had any emulsion with seawater and dieselfuel as you could have with lubeoil, but the latter did not have any water compensated tanks ( small tanks small surface effect)
Tore

[tore]

Maciek.
 As a follow up of my last post it might be a bit easier to look at the drawing below.
Tore 

[SnakeDoc]

Tore, thanks for answer. Could you mark the location of head tank in conning tower (if possible, using this drawings: http://uboatarchive.net/U-570GeneralPlan.htm)


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Thanks, regards
Maciek

[tore]

Tore, thanks for answer. Could you mark the location of head tank in conning tower (if possible, using this drawings: http://uboatarchive.net/U-570GeneralPlan.htm)


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Thanks, regards
Maciek

Maciek.
The head tank or may better buffertank is not a big tank,just big enough to keep a positive head in the system. It is fed from the coolingwater outlet at the exhaustsilencer, the location is about where I put the arrow on the drawing below.
Tore

[NZSnowman]

Tore, thanks for answer. Could you mark the location of head tank in conning tower (if possible, using this drawings: http://uboatarchive.net/U-570GeneralPlan.htm)


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Thanks, regards
Maciek

Maciek.
The head tank or may better buffertank is not a big tank,just big enough to keep a positive head in the system. It is fed from the coolingwater outlet at the exhaustsilencer, the location is about where I put the arrow on the drawing below.
Tore

Tore, can you remember approximately the dimensions of the buffer tank? As this would be a great little detail to add to my main drawing.

[tore]

Simon right now I cannot say the volume, you know the idea was not a supply tank and the space available in that area was not great. As you know the tower came in various executions but the design was made for a minimum of towercasing like the 1940 -41 execution. We stripped the wintergarden and reconstructed the towercasing with a minimum of volume keeping all the airducts, vents and buffertanks as originally designed.
Tore

[NZSnowman]

Fig. 1. Side view of new Air Starting supply piping.


Fig. 2. Top view of new Air Starting supply piping.


Fig. 3. New Air Starting supply piping under the decking. The layout is correct but the some of the piping and the

[tore]

Simon.
I guess the most probable place for  the supply from the 205 kg/cm2 mainline would be starboard above the floorplating. Looking at your photo showing starboard enginefront I have tried to indicate my proposal. Usually the small pipes are the 205 kg/cm2 pipeline and the larger 30 kg/cm2 lines. The indicated 205/30 kg cm2 reducingvalve has a handwheel, that could be a combination of a shut off valve and reducingvalve deviating from the pipeline drawing by making one unit. it is placed relatively easy accessable which makes it probable this is the HP main supply/reducing valve.  The manometers hardly visible outboard starboard could be local manometers showing the supply/reducing pressure because the manometers shown at the drawing you would find up at the instrumentpanel above the maneuvering stand. Se my drawing below and remember it is a guesswork ( hopefully intelligent).
Tore