Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Simon.
I`m a bit in doubt if the supply line from the compressor would be under the floorplating, I have a liking for outboard on starborad side.
Tore

[tore]

Simon.
Not all ideas are brilliant, I guess I have to revise a few details having given it a second thought.. I found that the HP air systemsketch and the starting air sketch are not in correspondence as they have different type of valves and only the startingair sketch have a direct line to the compressors. I thought the latter solution was a bit strange so I suggest to skip it and stick to the HP systemsketch. Further I have been able to see the details after the HP startingair supply valve and discovered the small airpipe and the filter after the valve so below is my revised proposal.
Tore

[NZSnowman]

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

Hi Tore

I been studying all my photo

[NZSnowman]

This is more confusing for me. Below is the port air bottle. I know that the red pipe is the inlet pipe (40 mm) to the Starting Manifold. The blue pipe (15 mm) is the drain line. But the line out of the bottle only looks 15 mm

[NZSnowman]

Tore, we know the HP bottle ends are the same. Could the German had the drain line at the lower bow end of the bottle (15 mm pipe) and the air outlet at the stem end (40 mm pipe)? This could be why we can not see the 40 mm pipe in the photo above?

[NZSnowman]

Tore, many updates to the side view.


Fig. 1. New updated drawing.


Fig. 2. old drawing.

[NZSnowman]

Tore, are the cover plates fixed by screws, bolts or rivets?

[tore]

Tore, we know the HP bottle ends are the same. Could the German had the drain line at the lower bow end of the bottle (15 mm pipe) and the air outlet at the stem end (40 mm pipe)? This could be why we can not see the 40 mm pipe in the photo above?

Simon.
I was home too late yesterday to look into this, but ready for action this morning. As you have noticed all the airvessels are tilting , this is because you want to collect the water at one end where you put the drain. I have look into the matter of outlet pipe a bit more before I have an answer and shall revert within short.
Tore

[SnakeDoc]

Tore, I was always wondering about Fuel oil venting, sounding and test piping :
http://uboatarchive.net/U-570Plate8.htm
http://uboatarchive.net/U-570Plate8A.htm
but I have never been able to figure it out entirely.
For instance, the following piping for inner fuel oil tank Treib

[tore]

Simon.
I guess we have to reconsider the whole thing. We have located the HP supply regulatingvalve, HP filter and the 205>30 kg/cm2 reductionvalve all placed on starboard side. Between these items are 20mm pipes. Out from the reductionvalve I have not been able to ascertain the pipedimension, but looking at the valvehousing I doubt if it is a 40 mm pipe out from this valve so I assume 20mm. We know that to and from the main startingvalve at the maneuvering stand the pipes are 40mm, thus the pipe from the airvessel should be 40mm.
The pipe at the forward end of the airvessel shown on your photo is definitely a full 20mm airpipe going upwards, hardly a drainpipe, the smaller pipe which can be seen could be a drain. I have not been able to locate any crossover. Unless you have any photos showing otherwise my proposal would be: The supply to the starting airvessels from the reduction valve on starboard side is 20mm, entering both  vessels at lowered forward end, which means that the crossover is a 20 mm pipe. The separate airsupply from the starting air vessel to each engine is from the aft end of the vessel (as you was asking) to the main startingvalve on the engine. It is no 40mm crossconnection.  Each engine takes its startingair from its "own" vessel by the 40mm pipe from the airvessel aft side, the 20mm pipe is only used for topping up (filling) the airvessels. The lay out is based on a direct reversible engine which has a large airconsumption (you have to restart every time you change direction of revolutions) thus the capacity of the airvessel should be for at least 10 starts before topping up.
Tore

[tore]

Simon.
Your update is excellent, pipedimensions better and even turning the coolingwater thermometers for  more convenient readings.
Tore

[tore]

Tore, are the cover plates fixed by screws, bolts or rivets?

Simon.
Hard to tell under all that paint,but I believe they were bolts with hexagon heads.
Tore

[tore]

Maciek.
Fueltank measuring.
You are particularly interrested in an easy description on sketch 3. On the posted sketch 3 below is red the partition between the green seawater and the lighter fuel on top. Remember the fueltank is always under positive pressure from the buffer/headertank. When you want to measure you equalize the pressure or fuel level in the testpipe by putting the cock in a position so the testpipe  gets an equal liquid level as the tank (red/yellow column in the pipe). When you turn the cock in measured drain position, the red/yellow liquidcolumn is sealed off and is forced by the positive head waterpressure into a inboard measuring canister. You shut off the drain when water is coming, how much water you get in the canister is irrelevant as the only liquid your measure is the fuel and that is accurately fixed. By a table relevant for that particular tank you can read of how much fuel is left in the tank.
Tore

[SnakeDoc]

Tore, many thanks!

and is forced by the positive head waterpressure into a inboard measuring canister. You shut off the drain when water is coming, how much water you get in the canister is irrelevant as the only liquid your measure is the fuel and that is accurately fixed

That's the part which I would never guess. Once again, thanks


--
Best regards
Maciek

[NZSnowman]

Simon.
I guess we have to reconsider the whole thing. We have located the HP supply regulatingvalve, HP filter and the 205>30 kg/cm2 reductionvalve all placed on starboard side. Between these items are 20mm pipes. Out from the reductionvalve I have not been able to ascertain the pipedimension, but looking at the valvehousing I doubt if it is a 40 mm pipe out from this valve so I assume 20mm. We know that to and from the main startingvalve at the maneuvering stand the pipes are 40mm, thus the pipe from the airvessel should be 40mm.
The pipe at the forward end of the airvessel shown on your photo is definitely a full 20mm airpipe going upwards, hardly a drainpipe, the smaller pipe which can be seen could be a drain. I have not been able to locate any crossover. Unless you have any photos showing otherwise my proposal would be: The supply to the starting airvessels from the reduction valve on starboard side is 20mm, entering both  vessels at lowered forward end, which means that the crossover is a 20 mm pipe. The separate airsupply from the starting air vessel to each engine is from the aft end of the vessel (as you was asking) to the main startingvalve on the engine. It is no 40mm crossconnection.  Each engine takes its startingair from its "own" vessel by the 40mm pipe from the airvessel aft side, the 20mm pipe is only used for topping up (filling) the airvessels. The lay out is based on a direct reversible engine which has a large airconsumption (you have to restart every time you change direction of revolutions) thus the capacity of the airvessel should be for at least 10 starts before topping up.
Tore

Tore, this sound great
 
I have no photo's of the