Luftwaffe and Allied Air Forces Discussion Forum

Luftwaffe and Allied Air Forces Discussion Forum (
-   Luftwaffe and Axis Air Forces (
-   -   Glider part? Company Luft - Stuttgart? (

Theodor 21st July 2010 08:23

Glider part? Company Luft - Stuttgart?
1 Attachment(s)
Recently I found this timer. German made and the BAL stamp suggests use by the Luftwaffe. Asked here and there, but so far noonne could tell me what it was used for. So, finally I contacted Isgus, the company that produced it. They most kind and sent me what they found about the piece:

"With our senior director we found out that this item is a altimeter for gliders. It was built until 1950 and we did only deliver it to 1 company: Company "Luft" in Stuttgart, Germany."

Unfortunately they had almost nothing in their archive about it, just the quoted. It has a clock mechanism inside, it is not an altimeter, but maybe is related to the altimeter somehow? There is a lever switching between 2, 4 and 10 hours. When on 2, the clock mechanism works much faster than when set on 10 hours. The mechanism rotates VERY slowly the axis on the back side, seems it was connected to some other device.

So, can you please tell me, what is this thing? What was it used for? And what is that Luft company in Stuttgart? Or maybe that means Luftwaffe? Thank you very much! BTW the diameter of the cylinder is 6.6 cm

Empiricist 22nd July 2010 07:05

Re: Glider part? Company Luft - Stuttgart?
The 1930s-1940s era gliders had five to six instruments:
- turn-and-bank indicator
- rate-of-climb indicator
- airspeed indicator
- altimeter
- compass

That was basic set. The Americans added directional gyro as well. That's all. Timer was not needed in the gliders.

Theodor 22nd July 2010 07:29

Re: Glider part? Company Luft - Stuttgart?
Yes, that's right. But I have one theory, probably about an optional instrument used on gliders and aircraft.

The manufacturers say it is an altimeter. Of course it is not, it is a clock mechanism. However they can not be wrong about it, so how can be a clock mechanism and altimeter related?

Thinking about the possible relation of the two devices, I reached my theory: could this be the driving engine of a recording altimeter, of an onboard barograph for recording the heights during the flight? An altimeter indicates the height and this wind-up engine rotates the rolls of paper. Quite possible? By chance, can you show me a picture of WW2 times German recording altimeter?

Empiricist 22nd July 2010 07:35

Re: Glider part? Company Luft - Stuttgart?
The altimeter mechanism is aneroid cell, never timer.

Theodor 22nd July 2010 07:55

Re: Glider part? Company Luft - Stuttgart?
Yes, I mean something different: the wind-up mechanism rotates the paper for recording the flight height data. Here is what I mean, the pictured instrument is not for aircraft, but shows what I am talking about: the aneroid cell and rotating mechanism working together in the barograph

Empiricist 22nd July 2010 08:18

Re: Glider part? Company Luft - Stuttgart?
1 Attachment(s)
As a glider pilot I flew many times with various types of the barographs on board of my glider. Those instruments I know represented 1940s-1950s era. In historical aspect I am also interested in this type of instrument. Frankly speaking I doubt that your instrument could be a hybrid of altimeter and barograph. I do not have a picture of WWII era German barograph but am posting below the US laboratory of the barographs. This image was taken in 1941. The barographs design was similar then all over the world.

If you are interested in I may post two images of late 1930s barographs. One of them manufactured by the Askania company, the other one by Bosch und Bosch.

Empiricist 22nd July 2010 08:58

Re: Glider part? Company Luft - Stuttgart?
One more remark...

The suggestion that your element belongs to untypical flight instrument is not bad. Pre-WWII there was a category of "special flight instruments" manufactured mainly for test flights. The leaders of those instruments were such companies as the Smith, Sperry and Askania. From your point of view the most important is Askania because it was the German company. The Askania manufactured, among others, so-called Mehrfachschreiber. That device had a cylinder to record graphically flight parameters from four classic flight instruments. That's why I do not tell that the hybrids of altimeter/timer/barograph were impossible. But the Isgus company is totally unknown in this sector of flight instruments market. The German leader in that sector was Askania.

Theodor 22nd July 2010 09:08

Re: Glider part? Company Luft - Stuttgart?
Yes, you are right, Jsgus are watch/clock manufacturers. But they only supplied the windup motor for the device - barograph or whatever it was. And the whole device was made by Lufft - Stutgart. The Jsgus were just subcontractors for one part.

I am not familiar with the Lufft company, however I found their website - the company was established in the 19th century and seeing its current production, it is very likely that it may have produced barographs, altimeters and other such stuff in WW2. That's them:

RedKnuck 8th September 2010 00:44

Re: Glider part? Company Luft - Stuttgart?
The Lufft company made, and still makes instruments - including barographs. I just found a WWII era one in my mothers toolshed, it is of manufacture Lufft and basically similar to the thumbnail picture in Theodore's post above. It has a small metal plate on the wooden cover next to the handle displaying a Nazi eagle holding a swastika by its claws and beneath is a big capital letter "M" and under that "16 N/G". It has a drum that rotates by clockwork, the clockwork in buildt into the drum itself. Outside the drum there is afffixed a recording paper, and on this paper an arm scribes a graph. The instrument measures (meters) atmospheric pressure just like a baroMETER - but records it in "writing" - hence the term baroGRAPH. The one I found used 7 days for a full rotation of the drum -the last recording was the 24th of March 1945. I assume it was intended for landbased stationary use. I have understood by browsing the web that the rotating speed of the drum varies with the application - another similar Lufft barograph made for the Kriegsmarine (German Navy) rotated in only 12 hours. It seems natural that a instrument to be put in an aircraft would need only to record for the duration of the mission which would be measured in hours. Since an aircraft ascends and descendes during its flight the barometric pressure would vary a lot, and to choose between different rotational speeds to fit the length of the mission and/or to display the curve more legible seems like a good idea. I believe that that Theodors "Isgus clockwork" is the barograph drum/clockwork itself, made for use in a Lufft barograph designed to be in an aircraft of some kind. Hence the options of three different rotational speeds. This matches well with the statement given from the Isgus company. Just my opinion after having done some preliminary research following the recent discovery of the WWII barograph in the shed - I am not a pilot or very familiar with WWII aerial operations. (But I buildt dozens of Airfix/Revell plastic assembly kits of WWII aircrafts during the early 70's - so I definitly have an interest in warbirds...)

All times are GMT +2. The time now is 08:02.

Powered by vBulletin® Version 3.7.2
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.
Copyright 2004 - 2018,