Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Simon.
From an engineering point of view it would be unnecessary and more spacedemanding to use a crossover of 40mm as the crossover is only a filling line and not a consumption line. German engineering is optimal so I don`t see why they should choose  a pipesize double of what is needed. You have to find a very good picture/argument to convince me of a 40mm solution.
Tore

[NZSnowman]

While rechecking the piping this morning I also noted there is a different piping layout between the port and starboard engine, between the air bottles and the starting manifold.  On the port engine the pipe follow the contour of the engine, on the starboard side the same pipe run forward for about 300 mm and then follows the main air vent down.
 
I will update my drawing to show this also.

[tore]

Simon.
Yes, but watch out for the coolingwater returnpipe from the exhaustmanifold to the inlet of the engine attached coolingwater pumps in the same area, it is easy to get mixed up as they are of aproximately the same dimension..
Tore

[NZSnowman]

Simon.
Yes, but watch out for the coolingwater returnpipe from the exhaustmanifold to the inlet of the engine attached coolingwater pumps in the same area, it is easy to get mixed up as they are of aproximately the same dimension..
Tore

Fig. 1. Port Side


Fig. 2. Starboard.
(source: U-995 DVD http://www.uboataces.com/u995.shtml)

[tore]

Simon.
Interesting photos. On stb side I guess you have noticed that on the reducing valve the outgoing pipe (30 kg/cm2) is  a bit  larger diameter than the ingoing (205 Kg/cm2). On the port side it is an interesting detail on the airinduction system which we can use when you shall go into details with regard to the supercharger system. Very good!
Tore

[NZSnowman]

Red  = 40 mm
Blue - 30 mm
Green = 10 mm



I found the cross over  You can just see it at the bottom of the photo.
(source: U-995 DVD http://www.uboataces.com/u995.shtml)

[tore]

Simon.
Well done!
Tore

[NZSnowman]

Simon.
Yes, but watch out for the coolingwater returnpipe from the exhaustmanifold to the inlet of the engine attached coolingwater pumps in the same area, it is easy to get mixed up as they are of aproximately the same dimension..
Tore

Fig. 1. Port Side


Fig. 2. Starboard.
(source: U-995 DVD http://www.uboataces.com/u995.shtml)

Here a better view of the port pipe, you can easily see how the pipe contour the engine and gone between the engine and the exhaust.

[NZSnowman]

Tore, what time zone are you in, is it GTM +1:00?

If so, being so far north, it must be getting dark very early currectly about 5:00pm??

[NZSnowman]

Tore, found a small error in the placement of the Air Starting Rocker Arm. It needed to move the end of the Rocker Arm, closer toward the fuel pump.


Fig. 1. New drawing.


Fig. 2. Old drawing.

[tore]

Simon.
New enginetop drawing.
Seems to be fine as usual, however I just noticed you give the exhaustvalve ample lubrication via two lines whereas the inletvalve has none. As far as I can see both valves have lubrication but at different inlet points, exhaust from the side and inlet from the top, see picture.
Tore

[tore]

Simon.
We are in the central Europe zone, GMT +1 hour. Right now it gets dark at 1600 and daybreak at 0900 in my area, but further north about half of the country don`t get sun at all starting at the North Cape in a few days.
Tore

[tore]

Simon .
Your new pictures showing the forward front and outboard side of the engine are great and useful for coming scrutinizing.
Tore

[SnakeDoc]

Hi Gents


I was able to find following information: the diameter of HP air piping leading to starting air flasks: internal - 36,5 mm, external - 44,5 mm.


--
Regards
Maciek

[tore]

Simon. On a few photos from the U 995 engineroom, outboard gratings are fitted between the engines and hullside. I cannot remember we ever had them and I don`t see the purpose for it . I guess they are installed to prevent visitors from crawling into that cramped space and suggest you skip it on your drawings.
Tore