Stocker & yale us lensatic compass

Good evening.

Thank you for your previous help on the MK111 Compass.
Can you help with another compass :
U.S
COMPASS,MAGNETIC
NSN 6605-01-196-6971
STOCKER&YALE.INC.
BEVERLY.MASS.
DAAK01-89-C-0125
3 AUG 89

I have enclosed two pictures of my compass, I believe that this is original.
I am trying to find out some information with regard to the back plate of my Compass,
as you can see it is blank and recessed,all the other I have seen so far are stamped and flat as seen on the third picture.
Could this be that there is no Hazadous material in the Compass or a production decision.
for completeness could another stamped back plate be put on or keep as per picture if correct.
The glass face is a bit foggy can these be cleaned or replaced.

Thank you for your time and help.

Regards
Michael

I wouldn't change anything. They didn't use tritium like on the other compass you have pictured. That's why your watch and compass have the 3H symbol and "dispose rad waste" on the watch.

On the NATO Stock Number lookup that NSN comes up as : Compass, Lensatic, Tritium, there are 3 colours available.

I would suspect that it was indeed Tritium filled, the warning disposal labels may not have been applied to these units until sometime in the 1990's.

However I am not 100% certain.

Thanks for the information.
I enclose two photo's one shows the dial as you can see on the North and the West arrow are a tad foggy and this makes it difficult to read the compass.The bezel glass is ok, how can I remove the compass bowl and remove the compass glass to clean.
The other photo shows the bowl with the back plate removed, one 'YOU TUBE' video show a chap removing the bowl with a pocket knife ,in my case the bowl is covered with in a rubber protective shell, how would I remove the bowl with out damaging the rubber protection, for this must come off with the bowl.Having a close look at the the bezel I noticed a cut in the bezel and can see two levers either side of the gap, could this be a way to remove the bezel
and get to the bowl?, if not what is there use?.
With the rubber protection could this be the reason that the back plate has no Hazardous warning stamped on, the compass points on the dial cannot be seen in the dark,but when a light is shone on the dial all is revealed, is this 'TRITIUM'.

Thanks again for your help
Michael

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Originally Posted by PARCHMENT

With the rubber protection could this be the reason that the back plate has no Hazardous warning stamped on, the compass points on the dial cannot be seen in the dark,but when a light is shone on the dial all is revealed, is this 'TRITIUM'.

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It could be Tritium that is outside it's service life. The typical luminous H3 paints and coatings will have a useful life of 10-20 years before they will no longer glow. It does not mean the Tritium is no longer present or a not hazard however.

Personally I don't consider H3 in military watches, sights, and gauges to be much of a hazard unless directly ingested, but you will have to do your own research and make your own health and safety judgement call.

On dis-assembly I can't tell you much, I don't really take delicate instruments apart personally, it's not quite in my skill set.

I don't believe it is tritium, because it doesn't have the warnings like the other compass.

I have done some research, at least online, and it appears that most, if not all, post 1960 built M1950 model compasses were H3 charged, the difference lies in individual manufacturer markings and official nomenclature. However I would expect, unless confirmed otherwise that all M1950 compasses contain H3.

http://olive-drab.com/od_soldiers_ge...s_lensatic.php

Quote:

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Manufacturing History of the Compass, Magnetic

From the 1950's into the 21st Century, the Lensatic Compass was procured in large numbers for the U.S. military ground forces, and other related uses. During that period a number of manufacturers were contracted to build the units and small variations in design were made. This chart summarizes some of the particulars of that history.

Year Manufacturer Nomenclature/Markings
1951 Lee and Stemwedel Inc. U.S. stamped, no other model id. Date 11-1951

1953 Marine Compass Co., Pembridge, MA U.S. stamped, no other model id. Date 2-1953

1960 Waltham Precision Instruments Dates 3-60 and 5-60. Radioactive warning label.

1964-1968 Union Instrument Corp., Plainfield, NJ U.S. Compass, Magnetic FSN 6605-846-7618, DA23-195-AMC-00906(T) 9-1966. Radioisotope H3 A.E.C. License No. 8-5970-9 Contains 75mc. Radioactive H3. Do not open. Dispose of per Busanda Inst. 5101.3. If found return to Military Authority. Other dates 1-64, 1-1967, 1-1968, 9-1968.

1966 Jay Bee Corp., a subsidiary of Stocker & Yale Inc. Compass, Magnetic FSN 6605-846-7618. Other dates 1-1970.

1975 Stocker & Yale Inc., Beverly, MA MAGNETIC COMPASS, NSN 6605-00-151-5337, 7 MAR 75, DA AK01-75-0-2147

1979 Stocker & Yale Inc., Beverly, MA U.S. Compass, Magnetic NSN 6605-00-151-5337 DAAJ09-79--0-5176 2 SEP 79. H3 content with AEC warning, DISPOSE AS RAD WASTE

1981 Stocker & Yale, Inc., Beverly, MA U.S. Army Compass, Magnetic, NSN 6605-00-151-5337, DAAJ09-82-C-A358, 15 DEC 81.

1989 Stocker & Yale, Inc., Beverly, MA US Compass, Magnetic NSN 5505-01-196-6971,, DAAK01-89-C-0125 3 Aug 89. SandY 183, 120mC1 3H. Controlled Disposal Required

1991 Stocker & Yale, Inc., Beverly, MA U.S. Compass, Magnetic, NSN: 6605-01-196-6971 3/91

1992 Cammenga Compass, magnetic, unmounted, lensatic, luminous, M2. Tritium Lensatic Compass. NSN: 6605-01-196-6971. Mil Spec: MIL-PRF-10436N.

Compass NSN 6605-00-151-5337 is deemed "operationally unserviceable" and compass 6605-00-846-7618 was condemned in 1978 for safety reasons and was not authorized for use thereafter. Both of these should have been replaced in military inventory with NSN 6605-01-196-6971

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The current NSN (6605-01-196-6971) of the OP's compass does identify as a Tritium source. I know from my experience working with my unit RadSO (Radiation Safety Officer) and running a Battalion worth of weapons vaults, that because of that designation alone we would have treated, accounted and stored these items in same way we controlled all other radioactive sources such as C79 Elcans, Silva Ranger compasses, Marathon watches, and C2 Mortar sights.

I am suggesting an err on the side of caution when it comes to guessing at this sort of thing.