Tores mailbox VIIC and VIIC/41 operation and technical details

[Don Prince]

Hello Mr. Tore,

I got the Gout about a month ago and my doctor gave me a 10 day prescription for Prednisone (A steroid) which resolved the painful problem... I get a severe case of Gout about 2 - 3 times pre year.

Regards,
Don_

[tore]

Don
Same thing here, but the last attack lasted 4 weeks, I am OK now.

[VIC20]

Tore, Rob Brassington, who created this awesome animation, is looking for information about the mechanism of the torpedo tube. The video shows his level of knowledge or simplifications for lack of better knowledge. Maybe you see things that should be different?


https://www.youtube.com/watch?v=CAO2BYZdfE4

[Don Prince]

Hello Mr. Tore,


Do you remember where this valve chest is located in the diesel engine room?


Regards,
Don_

[tore]

Don.
This valvechest is situated right underneat the writing deskplate port frontbulkhead in the engineroom.
Tore

[Don Prince]

Hello Mr. Tore,

I can see the valve chest for the Lube Oil located below the Desk Plate, but I can't locate the valve chest for the Fuel Oil in that area...

Don_

[tore]

Don.
As you know the aux. luboil pump could be used as an emergency fuel transferpump. This function was not likely to be used frequently and the connection to the fueltransfersystem was not as easy accessible as the aux. luboilpump function ( Used prior to every turning and start). I personally never used the aux. luboilpump as a fueltransferpump but as far as I remember the connectionvalvechest shown on the plate 9 was situated under the floorplating between the main engines hence not visible on the immage. If you look at the fuelpiping in and out of the fueldaytank (setlingtank) and on the front of the engines you have an idea of the considerably smaller pipingdimension.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you for the update and information. I believe Patrick will goto U-995 and attempt to get a photo of the Fuel Oil Valve Chest... He has been helping with the restoration and has unusual access to U-995.


Regards,
Don_

[Don Prince]

Hello Mr. Tore,

Can you verify if the market valved are the Fuel Oil Valve Chest?

Regards,
Don_

[tore]

Don.
I don`t think these valves belong to the fuel transfer system, hard to see the detail but I guess they are valves belonging to the ordinary luboilsystem.
Tore

[Don Prince]

Hello Mr. Tore,

FYI... You are correct about those valves belonging to the lube oil system...

It looks like the fuel oil pump was the easiest pump to replace, them the lube oil pump, and lastly the water cooling pump. How much time did it take to replace each of the three (3) pumps?

What was the failure mode for the fuel oil pump; It is gear driven and is well lubricated with fuel oil? I would think if a screw or nut got past the filter and jammed the pump gears, then an intermediate drive gear would have a shear pin so that nothing in the diesel engine side would be damaged. Was there an issue with the pump just wearing out and what usually broke?

I have the same questions about the lube oil pump and the water pump???

Regards
Don_

[tore]

Don.
Your questions might be unclear to some as it covers a lot, like fueloil-, lubeoil- and coolingwater systems, including the components, their maintenance and alternative operation. I guess it would be easier to split up the questions referring to each system separately. A full basic understanding of the discussed system is vital. Generally all systems have a number of alternative operationsolutions and sometimes you had to use your creativety and study the system plates to figure out which solution to use. No book could tell the optimal solution for every situation, experience and creativety of the engineroom crew had to be used.
Tore

[Don Prince]

Hello Mr. Tore,

Basically, how much time would be required to change out the Fuel Oil Pump, the Lube Oil Pump, and the Water Pump. If one (1) of these three (3) pumps were swapped out after a failure, then what was the main reason for the failure as observed during your service on U-Boats...

Regards,
Don_

[tore]

Don.
A HP fuelplungerpump, driven by the camshaft, 11/2-2 hours, the attached fuel supply pump, driven from the crankshaft up front 2-3 hours, the fueltransferpump electrically driven vertical IMO type trippel screwpump 8-9 hours. Hour estimations assuming sparepump available, apart from the camshaftdriven HP fuelpumps  normally no complete pumps stored on board. We had a few seized HP plungerpumps otherwise we did not have much trouble with the fuel/lubeoil pumps.
Tore

[tore]

Don.
The electric driven coolingwater pump did not give us any trouble, however on the attached piston coolingwater pump the conrod of the piston broke and smashed the cylinder. The pump is situated very low with difficult access up front of the mainengine and could not be repaired by us. Same pump was repaired at the submarine baseyard.
Tore