Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Don.
High voltage scheme.
I have finally been able to scan the high voltage scheme the original, as I told you, is pretty shot. Before I continue, could you make use of this quality? I am afraid the original isn`t much better.
Tore

[Don Prince]

Hello Mr. Tore,


I believe these greasing pumps are hand operated and not electrical, am I correct?


Regards,
Don_

[tore]

Don.
As far as the greasepumps concerns they were handoperated, you clearly see the handles on the photo below. The lubricators (Gruetzner) were rod driven by the main engines. These lubricators were supplying oil droplets to points were the dieselengine main luboil system could not be used. They a pretty easy to locate up front of the engines inboard port and stb.
Tore

[Don Prince]

Hello Mr. Tore,


Thank you for the quick response...  I updated Skizzenbuch and the "Maintenance" section is on pages 262 and 263, and it's in dropbox.


Good night, it's 2:20 am here in Georgia.


Regards,
Don_

[tore]

Don.
Checked Skizzebuch 10 page 262 and 263, OK.
Tore

[Don Prince]

Hello Mr. Tore and Maciek,


After going over some of the switchboard schematics from the U-Boat Museum, I realized I was confusing the Dead Slow speed with the single switch option Crawl or Creep speed.  This may have been an option on the older switchboards, but the current manual schematic we have it looks to be disabled.  Craw or creep would have put the speed at around 30 RPM (around 0.8 knots).  I guess the Germans needed more speed while submerged, and not less...


Mr. Tore have you ever heard of the creep or crawl speed while submerged in Kaura?  I guess Maciek will be glad I have finally seen the light!!!  I have up loaded a corrected version of Skizzenbuck into dropbox,


Regards,
Don_

[tore]

Don.
I never heard about creep or crawl speed submerged, apart from dead slow we had silent running.
Tore

[Don Prince]

Hello Mr. Tore,


I have a question about "Plate 6:".... The Main Drainage Pump can pump water into a drainage port or MBT 3.  Both end up sending the pumped water into the sea because MBT 3 has the flood valves open and the air pressure will force added water out the open flood valves (Kingstons) while surfaced.  Then again while submerged any water pumped will end up into the sea as well.  So is the drainage port redundant?


Regards,
Don_

[Don Prince]

The only thing I could forsee is if some of the blige water had oil.  Then it could be pumped into MBT3 so not to leave an oil slick.  The oil would remain in MBT3 floating on top of the water residual.


Don_   

[Don Prince]

Hello Mr. Tore,


I believe Silent Running was a test ran to determine which speed produced the least amount of noise.  Was that done with one prop or two?


Regards,
Don_

[tore]

Don.
Your assumption of the use of bilgewater outlet into MBT 3 is correct.
Tore

[tore]

Don.
Silent running was not a testrun. It was an order given to be as silent as possible trying to eliminate cavitation noise ( propellers), crewnoise and shutting down noisy auxiliary machinery. Once a year we had noisetrials laying semi submerged surrounded by microphones, starting up each axillary machinery one by one, recording the noise to establish the noisepattern in view of which items could be run under silent running condition, a kind of noise certification. You could run both propellers or one depending upon you noise pattern, (Cavitation)
Tore

[Don Prince]

Hello Mr. Tore,


On Page 82, where the crewman is using a claw tool to change the ballast tank configuration.  If the hand-wheels were removed from the gate valves, then would the claw tool still do the job or would he have to use a different tool?


Regards,
Don_

[tore]

Don.
The tools you mention were not only tools for the fueloil / ballasttanks configuration, but used for many type of valves. What you call a claw tool is a valve wheel wrench used on valves having wheel and hard to move. The other tool is a T bar extension tool used on valves  having no wheel and which could have an extension up to the deck ending in a small square supported by a connection in the deck or simply a valve deep down without a wheel or lengthening rod. In the case of the gatevalves for fueloil/ ballast tanks 2 and 4 they would act as blindflanges, very seldom used and as such I guess most EO would like to remove the wheels using T bar extension to reach the valves. If you look at the picture below you shall see permanent valve extension to the  in the deck for valve frequently used. For these connections you used the T- bar as well.
Tore

[Don Prince]

Hello Mr. Tore,


I added a maintenance section to the index and to Skizzenbuch.  Also, I added 2 pages to the torpedo section to get a better explanation of the firing valve and pilot valve, and I went through the complete book and corrected any wording or spacing errors.  Just about completed except for a page or two on the speed controller later...  I believe Skizzenbuch is getting very close to finished.  Also, I uploaded the latest version of Skizzenbuch to dropbox


Regards,
Don_