Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Simon.
Looking forward to seeing your new drawing.
Tore

[tore]

Simon.
Insulated handle.
I `m still not 100% sure about the purpose of this cock. Being a cooling water cock/vent it shouldn`t be necessary to have such a heat insulated handle, it would be more likely for an exhaustcock. But right now I cannot remember or see the use for exhaust cocks on each inlet to the exhaust manifold as you have exhaust thermometer pockets. You probably should just draw it, if I get ideas I`ll let you know. Below is a picture I made of the handle in case you are not familiar with the design.
Tore

[NZSnowman]

Hi Tore

I know that purple is the safety valve, but what is green?

[tore]

Simon.
A very good question. The green arrow point to the safetyvalve, if you see the drawing below, the startingvalve, fuelvalve and safetyvalve are placed on the centerline in the cross section drawing, which put a new question forward what`s in the place were we put the safetyvalve in the beginning? If you look at the drawing nothing protrude out of the cylinder covertop, and the object is outside the combustion space, e.g. cylinder. I`m inclined to believe this might be a cover for a castingcore opening in the cylindercover coolingspace. So I guess you can put the safetyvalve in the centerline and just indicate a cover where we erroneously placed the safetyvalve in the beginning.
Tore

[tore]

Simon.
Another idea struck me, probably more correct. The cylindercovers are the same on both engines but turned 180 degrees on the other engine. The watercooled exhaustvalves are forward of the inletvalves on both engines. Everything  which are in the centerline are OK and need not to be changed. The exhaust valvecasing and the inlet valvecasing are identical and fit in both valverecesses in the cover.When the covers for the other engine are turned 180 degrees the only extra opening in the cover has to be the coolingwater opening for the exhaustvalve casing and that matches exactly. The  plate in the cylindercover is the cover for the extra coolingwater connection to the exhaustvalve cage to be used when the cyl. cover is turned.
Tore

[NZSnowman]

Simon.
A very good question. The green arrow point to the safetyvalve, if you see the drawing below, the startingvalve, fuelvalve and safetyvalve are placed on the centerline in the cross section drawing, which put a new question forward what`s in the place were we put the safetyvalve in the beginning? If you look at the drawing nothing protrude out of the cylinder covertop, and the object is outside the combustion space, e.g. cylinder. I`m inclined to believe this might be a cover for a castingcore opening in the cylindercover coolingspace. So I guess you can put the safetyvalve in the centerline and just indicate a cover where we erroneously placed the safetyvalve in the beginning.
Tore

Hi Tore

When I was adding the safety valve to the drawing I thought it was centre line. I will update my drawing.

[tore]

Simon very good. I`m absolutely sure my last theory is correct. The superfluous opening in the cylindercover is for the exhaustvalve cooling if the cover is placed on the other engine.
Tore

[tore]

Simon.
Studying you last drawing I`m not sure about the placing  of the cock with the springhandle. I assume the drawing is stb aft. If you look at my drawing below I believe the
 cocks are placed aft of the coolingbends. On the aft cylinder the springhandle is missing. May be you drawing isn`t updated yet.
Tore

[tore]

Direct reversible engine.
In all descriptions on the dieselengines of the VIIc (GW and MAN) a direct reversible system is mentioned. On the drawings of the diesel a large cylinder is shown outboard next to the maneuvering stand, this is the reversing cylinder. On some photos the reversing cylinder can be seen. The most common way of maneuvering a submarine is by E-motors, in the RN and many other navies. On photos of the  on the U 995 engines you don`t see the reversing cylinder because the engines were not direct reversible, neither were the U 926 and U 1203 and these submarines were maneuvering by E-motors. My idea Simon is that all the newer VIIc diesel engines were not direct reversible and you should ignore this device on you U 1308 drawings. Below is a picture showing what I`m trying to say.
Tore

[NZSnowman]

Simon.
A very good question. The green arrow point to the safetyvalve, if you see the drawing below, the startingvalve, fuelvalve and safetyvalve are placed on the centerline in the cross section drawing, which put a new question forward what`s in the place were we put the safetyvalve in the beginning? If you look at the drawing nothing protrude out of the cylinder covertop, and the object is outside the combustion space, e.g. cylinder. I`m inclined to believe this might be a cover for a castingcore opening in the cylindercover coolingspace. So I guess you can put the safetyvalve in the centerline and just indicate a cover where we erroneously placed the safetyvalve in the beginning.
Tore

Fixed and updated

[NZSnowman]

Simon.
Another idea struck me, probably more correct. The cylindercovers are the same on both engines but turned 180 degrees on the other engine. The watercooled exhaustvalves are forward of the inletvalves on both engines. Everything  which are in the centerline are OK and need not to be changed. The exhaust valvecasing and the inlet valvecasing are identical and fit in both valverecesses in the cover.When the covers for the other engine are turned 180 degrees the only extra opening in the cover has to be the coolingwater opening for the exhaustvalve casing and that matches exactly. The  plate in the cylindercover is the cover for the extra coolingwater connection to the exhaustvalve cage to be used when the cyl. cover is turned.
Tore

Fixed and updated

[NZSnowman]

Simon.
Cyl cover- exhaustvalve piping.
Below is a picture showing my proposal of the piping, it might be the cockarrangement is different. This would be starboard engine, forward to the right. The cockhandle is on the other side of the cock and the ventingpipe ( blue ) is missing I believe.
Tore

Fixed and updated 

[tore]

You have been busy,I bet by now your drawing would give a very interesting top view look, in fact as accurate and a standard never seen before. But a lot remains to be done on the other sides of the engine,piping,airduct,supercharger, maneuvringstand exhaust ducts with pneumatic valvegrinder etc. A lot of fun ahead.
Tore

[NZSnowman]

Hi Tore

Can you remember how the rocker arm base was attached to the head? I can see one large bolt in the front, are there any other bolts holding it down?

Thanks, Simon.

[tore]

Hi Tore

Can you remember how the rocker arm base was attached to the head? I can see one large bolt in the front, are there any other bolts holding it down?

Thanks, Simon.

Simon. As previously said the rocker arm pedestal sit on the top of the recess for the inboard cylindercover short studs so no fixingstuds can be place there. On the top of the cover is an "ear" protruding inboard and outside the cover. In this ear is a hole for the rocker pedestal basestud of some 20-25mm I believe. You can clearly see the "ear" with hole underneath on Kubische Panorama. On the other side probably a little closer to the pedestal centerline you got to have a similar stud, but that is a bit hard to be seen. Don`t be fooled by the small nuts for the guide positionscrews clearly to be seen. It might be there is a better quality overheadsketch somewhere to be seen.
Tore