Tores mailbox VIIC and VIIC/41 operation and technical details

[NZSnowman]

Thanks Maciek

[NZSnowman]

Tore, was the only way to get the dirty LO off the boat was a hand pump?

[falo]

"Yes , much have been changed and I don`t understand some of the changes, the flood gates are the fingerprints of the submarine. It would not make much of an extra to put in some floodgates, they have blanked off some floodgates instead as shown on your photo. On the other hand they have put up an extra wind deflector on the radar casing which never was there on any VIIC, that cost extra and they have removed the original exhaust outlet and put in a new instead, that cost extra as well. Why if funds are short?
Tore"
__________________

I think further on money is very scarce but I agree they picked the wrong priorities. But some changes has a explanation: The blanked floodgates should stop those visitors of the boat who would like to climb on the wooden deck by using the floodgates as a "ladder". This concerns for example floodgates nearby the entrance and exit.

Thanks for your attached photos with the comments.

Regards
falo

[tore]

Falo.
Good to hear it is a rational explanation for the blanked off floodgates. Somebody has economical responsibilities for follies moving around, that`s probably why you have a grid shutting off the access to the tower. It is easy to forget she is now a museum allowing people to crawl all over, but why did they make a hinged manholecover easy to open on the saddletank as shown on the photo below?
Tore

[falo]

"but why did the make a hinged manholecover easy to open on the saddletank as shown on the photo below?"

Tore, to be honest, I don't know and I have not an explanation for that. Again the manhole looks not very accurate. Maybe this hole stores the tools and paints for the preservation team? Just guessworking about that matter.
Regards
falo

[tore]

Simon.
Dirty luboiltank pump.
The dirty luboiltank has no direct connection to an electric driven pump and normally you are only able to empty the tank by handpump. However the tank was originally connected to the purifier having both suctionpump and dischargepump connected to the tank. As you know the purifier was removed on the later version of the VIIC and VIIC/41`s.
The port and starboard luboil systems were normally operated separately. Thus in case you had a massive contamination of the oil, like emulsification due to watercontamination (it could happen), you emptied the relevant systemtank by the fueloil transferpump and did not use the dirty oiltank.
Tore

[tore]

Simon.
Maybe the dirtyoil tank handpump system requires an explanation. I `ll take one of Falos fresh photos as a reference. The handpump has suction via 3 way cock A, either from port or stb. systemtanks and discharge to the hose connection via 3 way cock B. Cock B has a 3rd outlet to a funnel which goes to another 3 way cock C. Cock C has two more connections  to the suctionpipe of the pump and via the cock A either to the port or stb. systemtank and an another connection to the dirty oiltank. As there are no non return valves in the system you can either fill or empty the tanks via the hose connection.
Tore

[NZSnowman]

Dirty Engine Lubricating Oil

One more system added to U-1308

Piping = Violet - Blue - Violet

[tore]

Simon.
Seems to be OK. Some small details. As usual the wooden handle of the handpump is gone , may be you should put it in. There is a small suctionhose connection right underneath the suctioninlet of the pump. My uploadfolder is full so I cannot show much pictures I am trying to see if i`ll manage after deleting a few old photos. I am notifying Wink.
Tore

[tore]

Hi Wink!
Just a test of my uploadfolder.
It seems to work! thanks Wink.
Tore

[NZSnowman]

Hi Tore
 
You may have noted the number of engine room drawings has slow down. I been busy sorting out my Master’s Degree. I hope to get back to it soon.
 
Was hoping to finish the engine room this summer but that not going to happen

Simon

[tore]

Simon.
After all we are having fun with a hobby, your education is of course more important. In the meantime I have prepared some sketches which might put some light on further details particularly in the engineroom.
Tore

[tore]

Simon.
Just keep busy with you studies and look into this whenever it suits you. I have gone a bit further into the fuelracks and governors of the main engines as your drawings have a few items missing on this system. May be you shall have a better understanding if I try to explain the working of the system. I start with the port engine as you know the starboard is a bit different. The basic is that the engineer is the overruling factor when he place the fuelhandle in the required position. If he want a higher revs he moves the handle so the fuelcontrol rod moves towards aft, turning the fuelpump plungers and thus increase the fuelinjection. The rod push the governor servo levers as shown on the sketch below, which means the servo piston goes down to a new fixed position and the whole linkagesystem turns around the fulcrum point A. The linkage (C )pulls down the servo slide admitting oil pressure to the top of the piston and drain underneath. At this position the new required revs is obtained and it is left to the governor to keep the revs stable. As the increased revs cause the centrifugal forces to move the weigths out thereby moving a sleeve and the connecting rod coming out of the camshaftcasing goes upwards. The rod is connected to a lever having a turning point at the servo pedestal which means the other end goes down and pulls A down. A is no longer a fixed point ( it has been shifted to B) and the servolinkage turns on fulcrum B.
This means the slide linkage point C goes down and the slide shut of the oil to the top of the piston and a new equilibrium  at the new higher revs has been established. The governor and servo shall "hunt" around this revs as the load varies. The lowering of the revs follows the same pattern in the opposite way. Just remember you first move the fulcrum B and then the system obtain balance at the new revs. by moving fulcrum A. How you are going to incorporate this on your drawing is not easy but as you see there are a few things missing. The linkage from governor lever to A ( adjustable) and one of the  two adjusting screws on the linkarm from servopiston to fuel controlrod.   
Tore

[tore]

Simon.
Governor linkage starboard engine.
As we have previously discussed the starboard engine is a mirrorexecution of the port except a few items. The fuelpumps and the governors are the same. In order to have the plunger inspection ( adjustment) window towards the aisle, the fuel pumps on starboard engine are turned 180 degrees meaning the fuelrack is moved opposite to the port engine. Thus for increasing the revs the rack moves forward. The governor servo is  the same as on port and not turned, and the linkage has to be different from the port linkage. For increasing the revs the fuelcontrol rod is moved forward (opposite to port) and  connected to the servo piston  via a trunnionshaft with levers to be able to connect the servo piston rod B which is  towards the centerline of the engine, the lever lift the servopiston to a new required revs position. At the same time the slide ( C) is lifted allowing oil pressue(red) to bottom of the servopiston and the whole leversystem is turning around A as the fulcrum. The increased fuelinjection rises the revs, the governor weights centrifugal forces lift the governor shaft coming out of the camshaft casing exactly as on port engine. As the servoslide connection point C is on the same side as the the governor rod you don` t need a balance lever as on port system, but only a supportarm hinged to the pedestal which means  (C) goes up ( opposite port) now using B as a fulcrum and an equilibrium   is obtained at the new fixed point B matching the required revs. I fully realize it there are a lot of links and levers but hopefully my sketch below having dozens of arrows  rather helps to explain and not confuse the system.
Tore

[Capt Kremin]

Hi Tore,
 
Sorry to distract you a little bit, but I have a question, if you don't mind.
 
It concerns the pressure hull.
 
When you served in the Kaurawas the pressure hull painted? if so. how often?
 
Regards
 
Jon