Gentlemen,
Looking at references, and I came across a similarity of two flat sheet metal mounts - one on a flimsy bracket on the Torpedo Room side of D.Spt 63, on the Bb side of the hatch. The other on a flimsy looking bracket mounted between D.Spt 8-9 in the aft torpedo room, just aft of the emergency steerage column.
There is nothing on these empty plates at the moment, but it looks to me as if they once held the same, or quite similar round things.
My first guess - was they were compass repeater mounts.
There is one here:
http://www.uboatarchive.net/U-570Photo4.htmSomething that size could easily fit on those mounting plates.
BUT. the U-570 ONI report states that:"There were six (6) repeaters located in the ship. Two were on the bridge, one in the conning tower, two in the control room and one in the sound room. Repeaters are self synchronizing. All repeaters were provided with 00 - 90 verniers. In addition, the two that were located on the bridge, which were pressure proof (without covers), had in addition to the azimuth and vernier scales an indicator which showed ships heading in three digit numbers. These indicators were at the centers of the repeaters. Only one switch must be closed to cut in a repeater."
That does not match my proposed idea. :-(
Idea#2: depth indication? Both would be useful near emergency steering, the aft torpedo room, and in the forward torpedo room.
Deep-diving Buordon-tube type depth gauge (One in control room had been sabotaged but one in the forward torpedo room was graduated to 200 meters)."
Just thoughts
Christopher