Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Maciek
We tested various alternatives and ended up with one diesel charging the batteries, eg coupled to the generator, tailclutch disconnected, and the other E-motor driving the propeller, diesel disconnected. Propelling the sub by E-motors made it easier (softer) to handle the snorting condition for the hydroplanepeople ( steady snortingdepth). Several times during direct dieseldriven propellers we dipped the snortmast floatvalve resulting in very uncomfortable air pressurefluctuations and sometimes the safetyvalve on the exhaust opened filling the sub with black exhaust. Snortingpropulsion by E-motors was definitely the most favourable alternative.
Tore

[SnakeDoc]

Hi

I can not remember for 100% but here is my guess.  There are two adjusting shafts on each main motor/generator. They are situated just above the stators and I think your may see a greasecup on the shaft casing, this, I believe, is wormwheel drive connected to the shaft. By putting a handle or wheel on the shaft you are able to turn it thereby the stators and adjusting the magnetic field of the motors/generators

That would be it! Accidentaly, in book "Die Sonar Anlagen der deutschen U Boote" by Eberhard R

[SnakeDoc]

Tore

We tested various alternatives and ended up with one diesel charging the batteries, eg coupled to the generator, tailclutch disconnected, and the other E-motor driving the propeller, diesel disconnected. Propelling the sub by E-motors made it easier (softer) to handle the snorting condition for the hydroplanepeople ( steady snortingdepth). Several times during direct dieseldriven propellers we dipped the snortmast floatvalve resulting in very uncomfortable air pressurefluctuations and sometimes the safetyvalve on the exhaust opened filling the sub with black exhaust. Snortingpropulsion by E-motors was definitely the most favourable alternative.

And when crusing submerged at low speed, wheter snorting or using battery, it was better to use one shaft or two? I mean, if boat had some better characteristics (ie reaction on helm), or it was meaningless?
--
Thanks, regards
Maciek

[tore]

M

Hi

I can not remember for 100% but here is my guess.  There are two adjusting shafts on each main motor/generator. They are situated just above the stators and I think your may see a greasecup on the shaft casing, this, I believe, is wormwheel drive connected to the shaft. By putting a handle or wheel on the shaft you are able to turn it thereby the stators and adjusting the magnetic field of the motors/generators

That would be it! Accidentaly, in book "Die Sonar Anlagen der deutschen U Boote" by Eberhard R

[tore]

Tore

We tested various alternatives and ended up with one diesel charging the batteries, eg coupled to the generator, tailclutch disconnected, and the other E-motor driving the propeller, diesel disconnected. Propelling the sub by E-motors made it easier (softer) to handle the snorting condition for the hydroplanepeople ( steady snortingdepth). Several times during direct dieseldriven propellers we dipped the snortmast floatvalve resulting in very uncomfortable air pressurefluctuations and sometimes the safetyvalve on the exhaust opened filling the sub with black exhaust. Snortingpropulsion by E-motors was definitely the most favourable alternative.

And when crusing submerged at low speed, wheter snorting or using battery, it was better to use one shaft or two? I mean, if boat had some better characteristics (ie reaction on helm), or it was meaningless?
--
Thanks, regards
Maciek

Snorting.
Generally speaking the sub had the best performance operating on two propulsionshafts, you did not have to compensate so much on the helm and the aft hydroplanes.
Tore

[tore]

Drifting a bit far from my normal topics I thought I should show you my recently completed showstand I made in my hobbyshop. The idea was to have have a piece of furniture that would give my wife's approval to have my model of KNM Kaura ex U995 in the sittingroom. As your see I have fitted LED ligth from top as well at the bottom. The latter was necessary in order to show the Kingstones (Flutklappe).
Tore

[SG]

Beautiful, i like it!

[TopherVIIC]

Tore, That looks outstanding! I may have to build something like that when I build my U-35 cut-away! I actually like the "flood-lighting" for the Flutclappe!


Christopher

[NZSnowman]

Hi Tore/SnakeDoc

I have finished another season in the snow, so I have time to continue working on U-1308. I have started to reread our old posts to refresh my mind about our discussion. This brings me back to the low pressure air sea weed air blowing cleaner system.

http://models.rokket.biz/index.php?topic=921.msg11832#msg11832

We initial presume that the small pipes (approximately 20 mm - purple color) were the low pressure line for this system, but I not to sure anymore, here why.

• We know that is system uses low pressure air, but I believe the presume pipes are too small for a low pressure system, I think you would not get enough volume of gas to do anything.
• We now know from the photo from the starboard side of the boat these presume pipe connect to the wrongs valve.
• These lines are not seen on the Port side of the boat where that are very easy seen on the starboard side.
• In both photo below we can see a larger pipe entering the correct valve (Green arrow), in addition, these pipes seem the correct size for a low pressure system.

I now believe these are the correct pipe (Green arrow) for the cleaner system.

PS. Tore, the display looks great.


Port Side
(source: U-995 DVD http://www.uboataces.com/u995.shtml)


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

[tore]

Simon welcome back from the snow, we are already getting some on this end and you are welcome to come over and move it away. As to the weedblowing system you are absolutely rigth. On the systemdrawings below I have indicated the way it is.
Tore 

[NZSnowman]

Hi Tore

Q: About the lubeoil separator (centrifuge) - Reply #355 to 358. http://models.rokket.biz/index.php?topic=921.msg11874#msg11874

Tore, do you know where the two lube oil separator are found? Are there under the decking?

[tore]

I cannot remember where, but I believe it was only one and according to the systemdrawings it seems to have been mounted on the port side forwd. It migth have been under the floorplating.
Tore

[NZSnowman]

I cannot remember where, but I believe it was only one and according to the systemdrawings it seems to have been mounted on the port side forwd. It migth have been under the floorplating.
Tore

Thanks, starting to all come back to me. I will have a look at a few drawings and see if I can workout something.

[NZSnowman]

Hi Tore/SnakeDoc

Does anyone know where the LP piping enter the engine room? Above or below/Port or starboard side?

I would think below deck and on the port side as the manifold in the Control Room was on the port side



(source: http://uboatarchive.net)

[NZSnowman]

Tore, the flow meter next to the lube oil separator, would it look similar to the one found in the forward torpedo? Thanks, Simon.

http://models.rokket.biz/index.php?topic=106.msg8197#msg8197


(source: http://uboatarchive.net)