Internet Horology Club 185
Navigation Master 4992b, 3992b and so on

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December 21, 2004, 12:50
Bernhard Schmidt
Navigation Master 4992b, 3992b and so on
Navigation Master 4992b, 3992b and so on...

Is it possible, when looking at the differnt sn (case and mvt), to check if the case is connected to the mvt or vice versa.

Bernhard Schmidt
December 21, 2004, 14:35
Greg Crockett
Hi Bernhard,

As far as U.S. made watches, cases were numbered independantly of the movements. The situation is different for Swiss products, such as the Navigation Master watches made by Longines. If cased at the factory Swiss matchmakers numbered their cases to match the movement serial number. If you have a Swiss watch in an American case, the numbers will not match.

Best regards,

December 21, 2004, 15:33
Lindell V. Riddle

Just to add a little, the watches in question of course have been around about six decades. During that time a lot of things could have been changed. There is a correlation between the government contracts on the case-backs and the time frame in which a movement was produced, but as Greg pointed out nothing actually ties a movement and case together. Bear in mind also that a reference to "Serial Number" as part of the ordnance numbers on a case-back is not related to the case serial number or the movement serial number. These watches and their markings can be very confusing.

The bench marks of authenticity in any watch collecting are the surviving unaltered boxed and labeled examples. We discussed a 4992B with early "US Army Air Corps" markings here...

"U.S. Army Air Corps" Marked Hamilton 4992B in Military Timepieces Forum

December 22, 2004, 09:27
Doug Romero
To continue this thread, here is an example of a 3992b that has 3C2260 marked on the movement, case back (stamped), dial, and outer box.

3992B movement

December 22, 2004, 09:32
Doug Romero
Case back with 3C2260 stamped on it.

Case Back

December 22, 2004, 09:35
Doug Romero
Dial on 3992B marked 3C2260. Looks like not added - could this have been done at time of manufacture???--

3992B dial

December 22, 2004, 09:43
Doug Romero
3992B Box plate marked 3C2260 and 88 on it.

By the way, anyone know what the 88 or the CH33 on the back would mean??

I've had this watch (in marked silver case) almost 20 years.

December 22, 2004, 09:45
Doug Romero

Front plate

December 22, 2004, 10:45
Terry Hill

Thanks for posting.......

I will offer an opinion...

The Stamping on the case back and the marking on the dial were done after maunufacture.... The broadarrow mark would have been done most likely in england.... and i would assume the dial marking there also. the tag on the box would have been done at the same time and location.....

the ordnance markings that are 'lighter' are from Hamilton.

no real ideas for the 88 or the CH33

on a side note....

According to contract records, the "vast majority" of these were sold to
The British Ministry of War Transport

There were some sold to Canada, but I am not sure Canada used the Broadarrow marking.

At this time, the only serial numbers DIRECTLY associated with the Contract records are

3C 2349
3C 2373
3C 2486

It is also noted that TWO 4992B movements were finished as 3992B design and the 4C serial numbers were retained on the plates.

4C 1656
4c 1657
The case numbers for these are also known....
December 22, 2004, 14:11
David Thomas
I have seen three different dials on the 3992B.

Doug's pictured above is the Canadian dial with the 24 hour markings.

The British dial is pictured below. Note the Broad Arrow.

In the 1950s some had the dials replaced by the Royal Navy Hydrographic department. These have an unusal decimal dial numbered 1 to 10.

Dave Thomas
December 22, 2004, 16:05
Bernhard Schmidt mean like this?......
Thank you everybody for your response.

December 22, 2004, 18:22
David Thomas
Yes, that's the decimal dial
December 23, 2004, 12:11
Greg Crockett
The above Hamilton started out as a U.S. Navigation Master Watch (per the identification on the case back). It was then provided to the Royal Canadian Navy as part of the “Lend Lease Program” of WWII.

The Canadian Navy re-marked the watch, as indicated. The Canadian Navy markings on the case back are actually C.H.S. 3 (the “s” apparently looks like an 8). This marking stands for “Canadian Hydrographic Service,” this branch of the Canadian (and British) Navy was responsible for timepieces among other things. "CHS" along with the number "3" is a code to indicate that the watch is a deck watch adjusted for isochronism in a minimum of two positions. Deck watches could be taken out on deck with the sextant for navigation; regulations did not permit the ships chronometer to be moved.

It is interesting to see the Canadians using the watch movement serial number as the issue number on case and dial. This is a rather old practice found on 19th century English watches. The US military did not repeat the movement serial number on the case. England and Canada often did so. The number 88 may have been a batch or control number of some kind. I can’t help you with that.

The Broad Arrow within a “C” on the back of the watch is the Canadian military property mark, placed upon all manner of military equipment from boots to cannon. The broadarrow standing alone without being inside of a "C" is the British property mark, as indicated above.

The number on the dial was probably placed there by the Royal Canadian Navy at some point when it was first inspected for service or sent in for repair.

Thanks for the pictures. You have a great watch.

Best regards,

December 23, 2004, 12:37
Terry Hill

Thank you for today's lesson on Canadian martial markings....

I, for one, appreciate it!
December 25, 2004, 21:44
Doug Romero
Guys -- sure appreciate the feedback. Greg thanks for the knowledge. I thought that it was marked for the Canadian Navy as you so nicely explained. Only could find sparse information in one of M. Whitney's books.

December 26, 2004, 05:53
Bernhard Schmidt
I wonder what the marks on mine stands for when it only got HS3 on the back, and it is overdrawn with three lines, what is the meaning of that?
December 26, 2004, 05:56
Bernhard Schmidt
I wonder what the marks on mine stands for when it only got HS3 on the back (think it is an "H" anyway, can be two l or something aswell), and it is overdrawn with three lines, what is the meaning of that?
December 26, 2004, 06:04
Bernhard Schmidt
Oh, I did not see it until I uploaded the picture. I found the broadarrow and it is not within a C witch means that this one was english propety.
Ged, you have a mission Smile

I anyway wonder what "HS3" stands for. Is it as simple as Hydrographic Service but the englishmen did not put an "E" or a "G" in front of the "H". The number 3 I assume have the same meaning as Greg explained.
December 27, 2004, 11:40
Greg Crockett
Thanks, Doug.

Whitney is a great writer. However, the best place to look for British watch codes is within A CONCISE GUIDE TO MILITARY TIMEPIECES by Wesolowski.

Hi Bernhard,

“H.S.” stands for, Hydrographic Service, the branch of the British Royal Navy charged with chronometer and timepiece inspection and repair. The H.S. codes may be found in the above noted book, by Wesolowski.

The WWII vintage watch you have pictured for us was re-issued by the British Royal Navy at some point after WWII. After the “H.S.” series of codes had been replaced by the NATO Stores codes, any watch passing through the Hydrographic Dept. at Herstmonceaux Castle had the earlier H.S. codes marked out. The first four digits of the new number, “0552" is a NATO stores number code for a Royal Navy issued watch. I suspect that if you check the movement serial number, you will find the last four digits of the movement number stamped into the back of the case, at the end of the more recent NATO stores issue number.

In the 1950's, ‘60's, etc. the Royal Navy re-dialed various pocket watches. Some of these older pocket watches received special decimal dials for quick calculations of minuets. This is what you have.

Thanks again for posting your images.

Best regards