Simon.
Coolingwater crossover.
Looking at your above system drawing showing the coolingwater crossover, I came to think about the execution of the crossover shut off valves. All 5 are gatevalves which we discussed previously, I seem to remember vaguely 3 of the valves (center) were operated by a T bar from a hatch in the floorplating that would mean no handle wheels. On U-995 the aluminium deckplating covers all hatches but if you have evidence otherwise you should ignore my frail memory, if not, it might be worth while to check.
Tore