A really bad disco, or ????

[zygoma]

Honest folks, I tried. I even watched Das Boot again (still don't speak German, no subtitles, etc.) and am still stumped.
The Type VIIB I'm currently driving in the English Channel enroute to my patrol area has white overhead lights that are on sometimes. At other times their red counterparts are illuminated. I haven't found a pattern; does it have to do with whether the boat's on the surface (so Bernard can open the aft loading hatch to pee over the gunwales), or when the diesels are running, or ???
To further complicate my meager grasp, in the movie there are also blue lights that seem to be on quite often. At at least one time during the movie (the second attack on the sub?) the red and blue lights are alternating.
I noticed the conning tower has red and white lights in the sim, but didn't notice in the movie.
Also -- what are the porcelain-looking round devices in the panel in the forward overhead of the control room? In the VIIB they're immediately above the single battery charge state meter by the Chief Engineer's station; in the IID they're on the starboard bulkhead, forward of the dive plane stations, and above what looks like either a water distiller or an oddly-placed compressor.
In the movie, during one of the attacks, several of the shells of the devices appear to be broken (they look like cones screwed into a panel that also has either switches or rheostats on it). Fuses come to mind, although having them so far from the batteries leaves an awfully long supply line that can short and cause a fire or battery explosion, if the lead between the voltage source and the fuse shorts due to damage.
And having more than one fuse in line to a load can sure lengthen the troubleshooting procedure if one blows and the other doesn't.
Perhaps I'm overthinking this, although that's an offense I'm *very* rarely charged with -- usually I'm dinged for not thinking at all :06:

So, any (printable) ideas?
Thanks yet again,
-- Zygoma --

[Tanedin]

I'm pretty sure the lights are indicative of the time day. At night you switch to red so your next watch shift can adjust their eyes to the dark. I think the porcelain-looking device is a speaking tube, not sure if we are thinking of the same thing though.

[Tinman764]

Yep, the lights are time based. White light destroys night vision, so red lights are used. It takes about 15 minutes to allow the eye to adapt and develop good night vision, but only a flash of white light will destroy it.
I think the blue lights are used in the parts of the boat that are crewed by the guys that don't need to build night vision and so blue at night is more comfortable to live and sleep in.

[zygoma]

Ah, OK. That makes sense -- thanks to both of you. I remember seeing the captain and part of his bridge watch wearing goggles (red, I think) before going aloft, presumably to help guard their vision, and even to make things illuminated by red lamps more visible?
The porcelain thingies I wrote of are different from the speaking tubes, I believe; those seem to be represented by screened funnels at the end of individual conduits, f'r instance at the navigator's station, and a couple of places on the bridge.
The porcelain (?) devices seem to be out of mouth's reach in panels that hold 30 or 36 or so in a close-spaced grid, which was what made me think that perhaps they were fuses. If I remember correctly from the movie, there are similar arrays in either the engine room or maneuvering, but I never remember seeing any replaced, even when some in the control room got broken during an attack.
Maybe when I grow up and decide what I want to do, I'll learn German. Or at least how to download a version of Das Boot with English subtitles....
-- Zygoma --

[Tanedin]

Oh, THOSE things. They do look like they could be fuses, have no idea what they are though...

[Captain Nemo]

Also -- what are the porcelain-looking round devices in the panel in the forward overhead of the control room?

Yep as Tanedin says, I think they are fuses.

Nemo

[postalbyke]

Confirmed. The fuse holders are located in the control room so as to be close to active watchstanders. This will allow quick changing, as well as quick isolation of malfunctioning equipment. On the type II, the device below it is actually the Gyrocompass system. Think of the fuse panel as also being a type of power distribution system, with one power cable coming in, and lots of power cables for other things coming out :D

Yep as Tanedin says, I think they are fuses.

Nemo

[Tanedin]

Credit has to go to Nemo for the fuses, I was just agreeing with Zygoma that they look like they could be fuses. Thanks for confirming it though.

[zygoma]

Many thanks to all. I enjoy being able to have some measure of immersive experience (submersive, in this sim ;) ) and so it's fun to know what some of the equipment is supposed to be for, even if there's no interaction with them.
In the case of the fuse rack, I actually have a similar arrangement in my Chrysler minivan for power distribution. I've got 6 two-way radios, chargers for a couple of handheld radios, and a scanner mounted, with separate fused power terminals for each. There's a 60-amp fuse mounted 4 inches from the battery terminal in case of a catastrophic short to the cable between the fuse panel and the battery. Yes, the van looks like a porcupine, and yes, my smarter half disapproves..... <sigh>
Makes me wonder if there's some sort of main breaker on the buss from the fuse panels to the battery banks in the subs. I learned early in my radio career how much smoke they put into the "big red" wires at the factory. Presumably one of the first switches or breakers that sub non-quals learn on the boat is where that one is, but it's just a guess, as I've never been aboard a sub that was still in service.
Again, many thanks for all the help. What a great community we've got here.
-- Zygoma --