Strange KM equipment

[BubbaZ]

Hi Guys,
A friend of mine found this on the flea market and asked me what is it? If this is really KM equipment and what was used for? I am not experienced in KM equipment but to my eyes it has something to do with maps and navigation?
All opinions will be much appreciated! The set consists of two boxes, each about one meter long, very heavy.

I enclose contents of first box.

Cheers,
Hubert

[BubbaZ]

more

[BubbaZ]

more of first box

[BubbaZ]

contents of the second box

[BubbaZ]

last image of the second box.

Sorry for bad images but I took those pictures with my mobile and the light conditions were very poor.

Cheers,
Hubert

[me6_130]

"All instruments for all branches of surveying. Supplier for the army and navy, Empire, State and local government authorities and industry."

Basically for map laying, I would say.


Carles

[BubbaZ]

"All instruments for all branches of surveying. Supplier for the army and navy, Empire, State and local government authorities and industry."

Basically for map laying, I would say.


Carles

Thanks Carles

Do you mean this was used for making new maps? So I understand this is kind of office equipment and not used on board?
Cheers,
Hubert

[compressore]

Station pointer

Hi,

the first instrument is a nice "station-pointer", in German "Doppel-winkelmesser".
It was used on board of ships for navigation in costal areas.
How it was used you can read here:
http://www.dehilster.info/navigation...on_pointer.php

Regards
Christian

[BubbaZ]

Hi Christian,
Thanks a lot, that's all I need
Cheers,
Hubert

[John R.]

Amazing that such an instrument was needed by any vessel, although that is exactly what it is, a navigational position instrument for coastal waters.

I have plenty of coastal and open ocean navigation behind me and never would have used this. What normally happens is that a quartermaster is on a bridge or bridge wing gyro repeater and takes bearings of three points on the coast, identified already by the navigation detail. He calls them out, such as "seagull point bears 089 degrees" and moves quickly to the next point. You need a decent spread in bearings. You lay out the bearings on a chart and then have a decent fix. You can also use a single point if necessary by running the bearing down the dead reckoning track.

If you were really moving, like a full speed destroyer, you would advance each bearing down the track to get your running fix to account for the time interval between bearing readings. Coasts without features can be difficult of course and if visibility is terrible, you need to use radar bearings also. In WW2, they did not have this option of course for most ships.

You also would have needed in WW2 to make sure what side of a point you were on before you changed course in case you really made a mistake in fog--Google "Tragedy at Honda Point" to see what can happen if you got confused.

In any case, an expensive piece of equipment for such an easy piece of work. In fact, not sure how they used it in practice. I can see the result, but you still would need to have the three bearings, plot them on a chart, then lay thing contraption over the bearings. I do not see the point of it and maybe that is why I never saw one on any vessel, naval or merchant marine.

John

[BubbaZ]

Hi John,
Thanks for your comment
Very interesting info about that Honda point disaster! Maybe if they used similiar station-pointers they could avoid the rocks...
Cheers,
Hubert

[John R.]

Well, no visibility at all and going about 30 knots. They took a reciprocal bearing on a radio station by mistake, so they said, which led to the disaster. I have been down to that beach many years ago. Not where you wanted to be.

John