Tores mailbox VIIC and VIIC/41 operation and technical details

[tore]

Simon.
I Guess your figure 2 would be the appropriate, just remember not to have any threads on the valvespindle going through the stuffingbox.
Tore

[NZSnowman]

Simon.
I Guess your figure 2 would be the appropriate, just remember not to have any threads on the valvespindle going through the stuffingbox.
Tore

It’s not perfect, but it came out much better than I thought it would. Hard to improve the model until we get some better photos or a diagram of valve.


Image has been resized. Click to view original image.


Image has been resized. Click to view original image.


Image has been resized. Click to view original image.

[NZSnowman]

Tore, according to the Kriegsmarine Color Codes for piping, bunkers, cells, tanks and pumps & the Design Studies - Type IXC, valves were marked with the same color code as the piping. Do you think the outboard valve handle were painted or was it a waste of time?

[tore]

Simon. Looks fine,  but might be you should make the flange bolts a bit shorter, the protruding threaded part outside the flange is of no use and make the dismantling more cumbersome than necessary.
Tore

[NZSnowman]

Simon. Looks fine,  but might be you shold make the flange bolts a bit shorter, the protruding threaded part outside the flange is of no use and make the dismantling more cumbersome than necessary.
Tore

Thanks, with update 

[tore]

Simon.
As far as I remember I don`t think the outbard valves had any colour code.
Tore

[Don Prince]

Hello Mr. Tore and Simon,


Is this the general idea behind the water compensation valve... My $0.02..


Regards,
Don_

[tore]

Simon, Don and others.
I woke up this night realising I have been conducive to a massive sabotage of the VIIC construction and am urging to come to a rescue. The simple design of the compensating valve having an outlet under the casingdeck would probably act as a modest vent for the fuel ballasttanks 2 and 4 when shutting the valve to the compensatingtank and simultaneously open the ballasttank to the atmosphere while surfaced. My previouse (but  not so elegant ) arrangement having the outlet by a second pipe down to the bottom of the saddletank in contact with the sea, prevented such venting. I like the idea of the compensating watervalve outside the saddletank, but I guess we have to have a second pipe down to a seawater connection at the bottom of the tank thus maintaining the ballast tank pressure while surfaced. The system has to be intergrated in the ballasttank by having a connection to the sea at the bottom of the tank in order to keep the ballasttank pressure. The seapressure at the bottom of the tank while surfaced would do this just as the open Kingstons are doing. I am sorry about this and as many times before I am afraid we probably have to find a new solution by the small expansion tank having seaconnection in the bottom of the tank. Does anybody have an image of the small bottom expasiontank?
Tore

[Don Prince]

Hello Mr. Tore,


I'm staying up so we can discuss the compensation system...  Plan 13 for the GW Diesel engine and the water circulation system seems to indicate that the cooling water:


1. First the cooling water goes to the exhaust muffler.
2. Then the cooling water looks to have some vents to allow the water to go to the sea.  I assume that don't want non-circulation water in the muffler because that would not cool the muffler. Therefore some of the cooling water must escape from the muffler.
3. Then the remaining cooling water goes to the header tank under the winter garden.


At this point we have cooling water in the header tank under pressure because the flow volume exceeds the leakage volume through the mufflers. 


On Plate 10 we see where the cooling water is distributed to all the internal and external fuel oil tanks. 


1. I see no problem if all of the tanks are in the fuel oil compensating mode because none of the tanks are open to atmospheric pressure and the cooling water system is closed.
2. If the 4 saddle tank compensation valves had a 3 position  "OFF" then that would eliminate opening the water compensation system to the atmosphere.
3. The 2nd position on the 4 saddle tank compensation valve would be for "Testing" the water pressure and flow of the compensating water.


This solution would only require 1 compensating water pipe in the saddle tanks... What do you think?


Regards,
Don_

[Don Prince]

Hello Mr. tore,


Back to the valve above the saddle tank. 


1. In the water compensation mode - the line is not open to the atmosphere but from the header tank to the saddle tank (Closed system).
2. Saddle tanks not in the water compensation mode - the valve has the saddle tank pipe shut (Closed system), and the valve has the header tank water flowing from the 2nd valve pipe to the sea...

If the water pressure from the diesel engine is not adequate to allow the drainage from the 4 saddle tank valves and maintain adequate water pressure to the internal tanks, then we would need an "Off" position on the water compensation valves under the deck.

Regards,
Don_

[tore]

Don.
I see your point of view, but my problem is if you look at the compensator water plan,  the  headertank outlet for the compensating water to the compensatigsystem is at the bottom of the headertank (no pipe up in the tank) and if the supply pipe to the saddletanks in the ballast configuration goes direct to the sea you`ll  drain the headertank in surfaced position..
Tore

[Don Prince]

Plan 10


Let's discuss Plan 10

[Don Prince]

The inlet pipe is up in the header tank...

[Don Prince]

If the surface position will drain the header tank, then the 4 water compensation valves need to have an "OFF" position....

[tore]

Don do you ever sleep?
I am convinced we shall eventually find a good solution within our free design, however as we are looking for a solution which should be as  close as possible  to the real design  we would have to use the resources available. The only reliable material I have at hand, as I explained previously we did not use the system, is plan 10 and a report on the system made by RN after an examination of U 570 later HMS Graph. An extract is below as well as plan 10. To me it seems obvious that the selectorvalve is a double seated valve ( not a cock) having three connections (positions): 1. from the compensating headertank. 2. compensating water to the bottom of the fueltank and 3. to the sea. It is only possible to select either 2 or 3. This was behind the rather un-elegant two pipe solution I proposed in the beginning.
I welcome any other solution within the basic infos available.
Tore