Tores mailbox VIIC and VIIC/41 operation and technical details

[NZSnowman]

Tore, here a small detail that we miss. Small metal box clamps holding the fuel lines on top.

[tore]

Simon.
HP fuel pipeclamps.
I you are right. Allthough they look like being insignificant they were important as they prevented vibrations which might lead to breakage and firehazard as previously mentioned.
Tore

[tore]

Simon.
Being at your revised drawing I shall introduce you to the air induction system not discussed before, I guess it would keep you busy during the weekend.  
The air induction is at moderate revs and load normal aspiration eg. the engine sucks the air from the engineroom to each individual cylinder. When the load and revs reach a certain level ( I believe 390 rpm) you had to switch in the double cone clutch for the Roots blower. The air is then at an overpressure supplied via an airduct from the blower to a common manifold connected to the inletvalves. This means that the direct individual air induction from the engine room to the inlet valves have to be shut. All this is done by a handle placed outboard and seen on the picture below. The handle was combined with the reversing handle, on the non reversible engine the handle is fitted as shown. By moving the handle you are turning a rod alongside the engine, the rod rotates and shuts the natural aspiration inlets and at the same time switch in the Roots blower clutch as can be seen on the picture below.
Tore

[tore]

Simon
Induction air system
Having read my post this morning I realize I should probably have expressed my shelf a bit clearer. The normal aspirated air supply enters the air manifold through two inlets in the manifold before going to the inletvalves. These two inlets are shut when the blower is connected by the blowerclutch handle. The fuel handle can not be moved to a higher preset filling unless the blower is engaged. Interlock prevents the startinghandle to move unless the blower is disengaged. All these  interlocks makes an intricate mechanical system of rods and levers which I don`t believe you should bother about. As to the reversible engine. It is no direct connection between the reversinghandle and the blowercoupling handle except the interlock preventing the engine to be run astern with blower engaged.
Tore

[tore]

Simon.
Exhaustmanifold protection.
I see you have put in the exhaustmanifold protection around the flanges. In spite of your clamps, vibrations sometimes caused the hp fuel line to break at the fuelinjector inlet and the fuel squirted right on to the flange area which you have now protected. I could not resist using your nice drawing to illustrate the situation.
Tore

[SnakeDoc]

Hi Tore,


I wonder about one thing. On the photo below (from U 570 diesel engine room) there are visible two engine order telegraphs and two pairs of shaft revolution indicators (one pair next to telegraphs and the other slightly behind the wheel of the main induction valve). I suppose, that the revolution indicators in the front are for diesel engines, while these in the back - for the propellers shaft, right?


(http://uboatarchive.net/U-570Photo26.htm)


Second thing - in this document: http://uboatarchive.net/Manual.htm (chapter Rudder order telegraph and rudder angle indicator system) it is said, that in diesel engine room was one indicator of the main rudder position. I was not able to locate it in the diesel engine of U 995. By analogy to the U 505, I would suppose, that it had to be on the fuel oil gravity tank...
Or maybe it was not installed at all? I don't think it has to be necessary in the diesel engine room...





--
Thanks, regards
Maciek

[tore]

Maciek.
You are right the rpm meters on the fuel daytanks, (headertanks) are the shaft rpm meters. I really can not remember any rudder angle indicator in the diesel room as you know a rudder indicator was in the E-room. In general you would not need to have a rudderindicator in the dieselroom allthough it would have been handy as at big rudder angle you would notice a heavier load on the engines.
Tore

[tore]

Simon.
Macieks photo from U 570 above shows the instrument panel as it used to be, crisp, with unpainted brass cocks and moderate painting not spotted with red paint as you se on the present U 995. I believe  you could very well use the above panelpicture as a model for your instrument panel drawing.
Tore

[NZSnowman]

Simon
Induction air system
Having read my post this morning I realize I should probably have expressed my shelf a bit clearer. The normal aspirated air supply enters the air manifold through two inlets in the manifold before going to the inletvalves. These two inlets are shut when the blower is connected by the blowerclutch handle. The fuel handle can not be moved to a higher preset filling unless the blower is engaged. Interlock prevents the startinghandle to move unless the blower is disengaged. All these  interlocks makes an intricate mechanical system of rods and levers which I don`t believe you should bother about. As to the reversible engine. It is no direct connection between the reversinghandle and the blowercoupling handle except the interlock preventing the engine to be run astern with blower engaged.
Tore

Tore, how does my Induction air system look like?

It was hard to draw, as I have no photo's and a drawing from only one view

[tore]

Simon
The overall picture is good. I guess there are not many details to be shown on a top view, when the Roots blower is fitted it would help together with a frontview. I`ll keep looking and see if I can provide with more details.
Tore

[tore]

Simon.
Below a cossection of the engine showing the airmanifold in superchargermode and the rod engaging the clutch and shutting the the natural aspiration inlet.
Unfortunately I do not have any drawing or photo showing the manifold may be somebody could help?.
Tore

[TopherVIIC]

I am looking in my (admittedly limited) sources Tore. I used to blow stuff up. I do not do that now... but I will try and see if I have anything to offer that is positive my friend...

[NZSnowman]

I used to blow stuff up. I do not do that now...

I blow up stuff also...but only snow

Christopher, have you ever made any in holes in snow, or only in metal?

[TopherVIIC]

Simon....
I learned much about blowing stuff up in S.korea... and blew up snow there.. It was winter there... and I admit I focused on hardware that N. Korea was using.... then I was sent to the Iraqi venue.. I am sure you would like Det Courd... orange line...with an electric explosive cap...
we sent snow to the bottom of he casm where we needed it. We sent metal to the heavens when we needed to. As a Marine, focused on my nation's goals... I did my work...

[TopherVIIC]

If one is not military... one need not actually know about methods of sapping, or explosive devices.

moving on... Politics are not this forums goals. Not political here.
Christopher.