Kriegsmarine Sextants

[John R]

Attached are images of my sextant. It belonged to either U-873 or U-234, still doing a bit of research.

Anyway, I am not sure how you know if it is a first or second type sextant for a start.

I note that the sextants in Torpedo Los for the most part had different numbers on the index arm than the graduated arc. I assume that this meant the number on the arm was a control number and the number on the arc was a serial number for the sextant since it matches the certificate. My certificate is dated 27 April 1939. However I have also seen sextants with matching numbers, maybe they changed the system at some point.

I also assume mine is aluminum, not bronze. But might as well post it to make sure. It is not that heavy and I do not note anything that strikes me as bronze which is the case with US Navy WWII sextants.

John

Edited September 8, 2007 by John Robinson

[John R]

more photos

Edited September 8, 2007 by John Robinson

[John R]

more

Edited September 8, 2007 by John Robinson

[John R]

My US Navy 1944 Mark II Mod 0 Bendix sextant for comparison.

[John R]

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[John R]

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[John R]

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[nesredep]

Hi

One from my collector friend.Made by C.Platt Hamburg.

Nesredep

[nesredep]

Hi

Lable from the wooden box.

Nesredep

[nesredep]

Hi

Sextants in use.

Nesredep

[John R]

That is a nice photo, any more out there of the sextant in use at sea?

It is my impression based on some experience at sea as a navigator, that the IWO actually had the responsibility of taking the "sights", not the leading quartermaster to use the US title who is listed as "navigator" in U-boat books. I think the enlisted man was responsible for keeping up the charts, calibrating the sextant, electronic navigation, many other duties, but when it actually came to taking sights with the sextant, it was the IWO and sometimes for training the IIWO but I might be wrong.

I never have seen a photo with a sailor taking the shots, always an officer. So what I think happened is that the officer took the shot, shouted down the reading, and the "navigator" logged the reading and started working out the calculations to provide a navigational solution. Maybe on a nice day, the navigator would stand next to the IWO with a pad and the stopwatch and write down the angles at the same time logging from the stopwatch how many seconds had ticked by so later he could get the correct GMT which you need as an entering argument for any navigational problem. Meaning, he added the seconds to the previously recorder chronometer reading.

Yes, I was a navigator and taught navigation at a merchant marine school, that is why I am a bit dubious that the enlisted navigator (steersman) actually used the sextant too often, but of course, he could have since every quartermaster I ever met was quite good at it.

On a large ship, like a cruiser and battleship, there would be 3 or so men out there all shooting the same stars at the same time more or less in order to get the best possible fix. I do not see this as the case with a submarine.

As a side note, drop one of these sextants and see what happens. The recalibration effort is monumental and quite frustrating. If you bend the arm or arc, forget it.

John

Edited September 9, 2007 by John Robinson

[John R]

The officer in your photo is taking a "sun line" by the way, which can give you a very accurate latitude and a decent logitude if you get enough "sights" and have a decent starting point, but the longitude would not be good enough usually to meet up with another U-boat although you would have an idea where you were and certainly you would know your exact latitude. It was the longitude that was the problem.

Since I do not see a recorder, this officer must be shouting down a voice pipe or through the hatch to the navigator his readings, which makes the most sense to me. The man standing behind him I believe is just doing a search, has nothing to do with navigation. John

Edited September 9, 2007 by John Robinson

[John R]

I still would like the members that know to explain how you know if it is a first or second type sextant and if my sextant is aluminum or bronze. I assume aluminum.

Also like to see other sextants if members have them.

These sextants were carefully treasured, some were just rotten out of the box, others very accurate. When you had a good one, you took care of it. No banging around, they were delicate.

John

[nesredep]

Hi

I hope it is ok I post this papers here.

Nesredep

[nesredep]

Hi

More.

Nesredep

[nesredep]

More.

[nesredep]

Sorry,this first.

Nesredep

[nesredep]

[nesredep]

[nesredep]

[nesredep]

Hi

And the last.

Kind regards

Nesredep

[Michel]

Hello,

The difference between the first and the second type (mid-war) of sextant is done mainly by the bracket (potence in French) of the sextant.

The first type can be made in bronze or aluminium.

Regards,

Michel

[John R]

Hello,

The difference between the first and the second type (mid-war) of sextant is done mainly by the bracket (potence in French) of the sextant.

The first type can be made in bronze or aluminium.

Regards,

Michel

Not sure what you mean by bracket. There are many brackets on a sextant from the mounting bracket in the case to the many brackets that hold the mirrors, filters and scope.

If the first type, which I assume mine is since it dates from 1939 without reference to a bracket, can be bronze or aluminum, can you tell if the one I posted is bronze or aluminum just by looking at it? I would think an aluminum sextant would be fairly light, but not sure if you define it as bronze or aluminum by the main frame of the sextant which is painted or by the graduated arc which seems to be either black or metallic.

John

[KM-SPAIN]

My old sextants, now they have gone, but I hope that soon I will find again another nice one.

A broze one.

[KM-SPAIN]

Other example made in aluminium in june 1944.