Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Simon
Exhaust coolingwater.
I don`t think so Simon. I`ll check and see if I can figure out this.
Tore

[tore]

Simon.
I guess the reliefvalve of the exhaust manifold was installed on schnorchel boats. We had a few times experiences while schnorchelling that the relief valve opened as a consequence of dipping the mast and the exhaust backpressure became excessive. The engine room was filled with black unpleasant exhaust.
Tore

[NZSnowman]

Simon.
I guess the reliefvalve of the exhaust manifold was installed on schnorchel boats. We had a few times experiences while schnorchelling that the relief valve opened as a consequence of dipping the mast and the exhaust backpressure became excessive. The engine room was filled with black unpleasant exhaust.
Tore

Thanks Tore. I thought the relief valve was for the cooling water.

[tore]

Simon
Main engine exhaust manifold.
The crossection drawing shows engine looking towards the forward end , see drawing below, the reversing cylinder up front is removed on the later engines. There are no indications of any objects or restriction flanges towards aft and I can not see any reason why such restricton in exhaust manifold diameter should be justified.
If you look at the photo below showing the forward exhaust manifold endcover there are two reasons why this is not the main endcover, only 6 small fixing bolts whereas on the exhaust manifold flanges you have 12 fairly sizeable bolts, there is obviously a large hole in the cover for the reliefvalve. Based on this my assumption would be the shown forward endcover is just a protection cover and behind is the cast double wall cooled end dome being the real cover. In the end dome is an inspectioncover having a smaller diameter than the  exhaust manifold and the drawing shows this inspection cover.
Tore

[NZSnowman]

Tore, just double checking, the exhaust manifold is double wall with the cooling run in the outer ring?

[tore]

Simon.
The exhaustmanifold is casted like a double wall pipe and  the coolingwater flows between the outer and inner walls, at the forward end piece I guess the casting could make a double bottom, like a bottom of a glass thermo bottle. In this bottomplate is the inspection opening having a smaller inspection plate. A possible alternative could be that an uncooled steelplate is just flanged to the manifold, that plate would have a smaller inspection opening covered by a steelplate. The outer visible plate with smaller bolts provide a heatprotection.
Tore

[NZSnowman]

Simon.
The exhaustmanifold is casted like a double wall pipe the coolingwater flows between the outer and inner walls, at the forward end piece I guess the casting makes a double bottom, like a bottom of a glass thermo bottle. In this bottomplate is the inspection opening having a smaller inspection plate. The outer plate with smaller bolts provide a heatprotection.
Tore

All make sense now
I had been imagining it was the other ways round
What was why I been asking all these questions about the exhaust manifold, as I could not get my head around it

[NZSnowman]

Simon.
That may be.  I think I have seen a drawing of the compensating box in the bottom of the saddletank. See below,  I made a rough pencil sketch indicating where to look for it you have more materials to look into than me.
Tore

This could be that pipe on the U-534

Simon. Interesting detail, it certainly could be the box, I only miss the pipe out of the box. The idea was to have a buffer preventing contamination into the compensating system. Howewer the most important pipe for that was the fueloil venting pipe  which ended some 10 cm from the bottom of the ballast/fueltank. When fuelling, the ventcock was open and a guy watched the water coming out and stopped the fuelling when he discovered fuel coming out, but as the pipe ended 10 cm above the tankbottom you could never force fuel into the compensatingpipe as the fuel was flowing through the ventpipe leaving some 10 cm of water in the tankbottom saving the compensating system. This was  before pollution and environment questions was a topic. Anyhow see to it that your fuel ventingpipe is not leading all the way to the bottom
Tore

Simon.
Compensating expansionbox.
As to my yesterdays post I have given it a second thought. I believe the device and connecting pipe on the picture is too small for being the box. Estmating the capacity of the tank to be some 12 tonnes of fuel I guess it should have a volume about 150-200 liters ( almost an oilbarrel).
Tore

Tore, I was thinking about the small box shape at the bottom of the saddle tank and next to the pressure hull could it be the echo sounder?

[tore]

Simon.
Echosounder
I don`t know the details of a IXC very well, but this is an unusual place for a echosounder, I really could not say for sure what the "box" is.
Tore

[SnakeDoc]

Tore, I was thinking about the small box shape at the bottom of the saddle tank and next to the pressure hull could it be the echo sounder?

I'll check in the evening, but as I remember, echo-sounding transmitters and receivers were located rather near the keel. Hard to say what it can be...


--
Regards
Maciek

[NZSnowman]

Updated exhaust manifold

[tore]

Simon.
As usual everything looks very good. I am a bit doubtful to the exposed manifold flanges. If I remember well they were covered by asbestos!!cushions and protected by an steelsheet plate, see yarddrawing. The reason for That is the uncooled bare flanges gets very hot and a possible bursted HP fuelpipe might squirt fuel hitting the flange which immediately ignites.
Tore

[NZSnowman]

Simon.
As usual everything looks very good. I am a bit doubtful to the exposed manifold flanges. If I remember well they were covered by asbestos!!cushions and protected by an steelsheet plate, see yarddrawing. The reason for That is the uncooled bare flanges gets very hot and a possible bursted HP fuelpipe might squirt fuel hitting the flange which immediately ignites.
Tore

Thanks, Tore.

I will update my drawing.

[SnakeDoc]

Hi,

Tore, I was thinking about the small box shape at the bottom of the saddle tank and next to the pressure hull could it be the echo sounder?

I'll check in the evening, but as I remember, echo-sounding transmitters and receivers were located rather near the keel. Hard to say what it can be...

Eberhard R

[NZSnowman]

Hi,

Tore, I was thinking about the small box shape at the bottom of the saddle tank and next to the pressure hull could it be the echo sounder?

I'll check in the evening, but as I remember, echo-sounding transmitters and receivers were located rather near the keel. Hard to say what it can be...

Eberhard R