KM instrument?

[François SAEZ]

Another item I have no idea of its use
Thanks for your help

[François SAEZ]

a

[François SAEZ]

b

[François SAEZ]

c

[WWIIBuff]

It looks pretty cool whatever it is.

[compressore]

Positioning circle

This is called "Ortungskreis" (positionig circle)

Its a similar instrument like the "Peilscheibe" but this one will be put on the map during measurements.
Land based objects will be targeted and bearings will be noted on ! the transparent disk.
With the targeting of three objects the current own position is absolutely precise marked on the map.
It used the when compass of the ship is not working or misaligned/deviation is so high that the deviation table on the chart is not enough to correct (the Pfeilscheibe is working together with a compass)

Manufacturer is Sprenger Optisch-mechanische Werkstätten in Berlin

Regards
Christian

P.S.
No, I have not studied navigation...its described in the manual shown in post #4

[François SAEZ]

Many thanks Christian (I don't speak German)
All kind of boats, including U-boots?
Best

[compressore]

Magnet compass....

Hello,
it is written in the description:
Especially on ships which have only one "Magnet compass" as this only one is maybe is not functioning so this device is a back-up when sailing under land.

I do not know if this device was used on U-Boats too as they do have other back-ups.
I understand the usage on small vessels like fishing cutter etc. ...as they do not had the fancy gyros compasses etc.
Nevertheless a nice item.

Regards
Christian

[km-spain]

Hello, I have also one of these in my collection.

As Christina has identify it is a Position Circle, which was placed on the ship compass to determine the position of the ship by correcting the effect of magnetic perturbations in this, marking with a pencil on transparent circle three directions of reference once triangulated they marked the position of it.

[François SAEZ]

thanks both