How does damage control work?

[maillemaker]

So I'm on my first mission, using Wolves of Steel mod.

Sail into the Baltic bay, and next thing you know I'm getting shelled by a destroyer that can't be more than 3000 meters behind us. Why my crew never saw it, I don't know.

Anyway, I dive.

We sink, uncontrolled, to the bottom at like 70 meters.

I can't figure out damage control.

It doesn't help that all the systems are labeled in German, but anyway the descriptions are in English.

I assume if a system is red and at 0% it is destroyed?

Why is it when I click on a system, and a little beating hammer appears, if I go to another compartment and come back the hammer is gone? Have repairs stopped?

Do I have to create a damage control team like in SH3?

I had a lot of injuries. I tried talking to my chief engineer and getting him to control flooding, but he kept saying he could not do that right now. There was a clock time beside "repair critical systems" (item 1).

So I just kind of stood there until my sub self-destructed.

How do you operate damage control?

Steve