Type VII Interior Tour Series

[Onkel Neal]

Ok, good deal, thanks.

Another question, if I may: 49:30 that TBT link for the night scope, is there a separate one for the UZO and attack scope?

[derstosstrupp]

Originally Posted by Onkel Neal

Ok, good deal, thanks.

Another question, if I may: 49:30 that TBT link for the night scope, is there a separate one for the UZO and attack scope?

Yessir. The attack scope one was mounted on the scope itself on the backside (opposite side of where the operator sits). The UZO one is inside the UZO column itself.

[BrendaEM]

@derstosstrupp, thank you for the reply. Oddly, the Norwegian cream color is fairly close, as the original German requirements, specified the RAL color, and called for Ivory. I agree, that stated, the incandescent color temperature would warm it still a bit more.

@Nimmo55, the translated colors for the deck are here, too:

: https://www-u--boot--archiv-de.trans..._x_tr_pto=wapp

Ref: https://en.wikipedia.org/wiki/List_of_RAL_colors

[Onkel Neal]

Last two questions:

Ready lamps, 5 of the them, two rows: are they lit when it is safe to dive?

Starting the diesels, they could start them with the e-motors, was that the normal method or was it more routine to start with air?

Oh, and you said there should be 3 hydraulic resevoirs next to the attack scope well,

is that 3 with a non-snorkel boar?
Or 3 with with snorkel or non-snorkel?

I thought the 3rd reservoir was for a snork-boat, the non-snork boats had 2, 1 for each scope...?

thanks!

[derstosstrupp]

Originally Posted by Onkel Neal

Ready lamps, 5 of the them, two rows: are they lit when it is safe to dive?

Correct, they are lit when ready/safe. In the case of the hull valve section, they light up when the electric sensors on the respective hull valve wheels detect that they are shut. In the case of the dive ready lamp section, they light up when the heads of the individual compartments flip the switch in those compartments that their compartment is ready for dive.

Originally Posted by Onkel Neal

Starting the diesels, they could start them with the e-motors, was that the normal method or was it more routine to start with air?

It was normal to use the e-motors to start when traveling in diesel-electric mode, which was used for much of the patrol. This is traveling on one diesel used for propulsion, that diesel turning its prop and also the motor on that side as a generator to generate power for the other side’s e-motor, which is turning the other side’s prop. Since they would have the other side’s motor running in this configuration anyway, to save on compressed air, they would simply start the other diesel with that E motor when they switched out the diesels every four hours or so in order to grind the exhaust valve seats.

Originally Posted by Onkel Neal

Oh, and you said there should be 3 hydraulic resevoirs next to the attack scope well,

is that 3 with a non-snorkel boar?
Or 3 with with snorkel or non-snorkel?

I thought the 3rd reservoir was for a snork-boat, the non-snork boats had 2, 1 for each scope...?

Based on what I have seen in early type VIIC design documents, it was always three. For instance here is part of a schematic from the Bootskunde für VIIC from 1940:



Same for the U-570 Skizzenbuch diagram for hydraulic system (earlier-war VIIC):

[Onkel Neal]

Originally Posted by derstosstrupp

when they switched out the diesels every four hours or so in order to grind the exhaust valve seats.

Wait, what? Grind the exhaust valve seats? That must have a very different meaning from grinding valve seats on an automotive engine... You must be referring to the exhaust valves in the line, not the heads, right?

[derstosstrupp]

Originally Posted by Onkel Neal

Wait, what? Grind the exhaust valve seats? That must have a very different meaning from grinding valve seats on an automotive engine... You must be referring to the exhaust valves in the line, not the heads, right?

There were flapper valve seats in the external and internal exhaust vents. Carbon would form on them and prevent a good seal when diving, and so periodically they needed to be ground. The external ones had pneumatic motors that would do it, but the internal ones you had to do by hand. You’d slap a big ratchet handle onto this male end here and crank back and forth for a while to unseat the carbon. Rinse and repeat on the other engine 4-6 hours later. Buchheim had the pleasure of doing this and describes it in Das Boot when he stands a diesel watch.



Some early boats were lost due to this design flaw.