Master Navigation Watches: A-9; A-13; 5740; and 5740-1

grtnev

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The following three threads provide useful background.

https://mb.nawcc.org/showthread.php?30964-Army-Air-Corps-Center-Second-B-W-Raymond&highlight=master+navigation
https://mb.nawcc.org/showthread.php?100550-Hamilton-and-waltham-gct&highlight=master+navigation
https://mb.nawcc.org/showthread.php?136951-Elgin-A-13-Master-Navigation-Watch&highlight=AN5740

Summarizing the latter/post Weems development of the Master Navigation Watch which eventually evolved into the AN5740-1 variant:

The A-9 was the first variant that had a "hack" feature and was manufactured for the U.S. Army Air Corps by Longines. The hack feature was a slide bar at approximately the 2 o'clock position on the case. To the best of my limited knowledge, this watch was only manufactured by Longines. A question to the members of this forum: Is anyone aware of any other manufacturer of the A-9 other than Longines?

The A-13 was the first variant to include the "hack" feature into the stem. Pulling out on the stem stopped the movement. The A-13 has a white dial, with the minutes marked from 0-55 and the hours marked from 0-23. "GCT" is marked below the center of the dial. The hands are narrow, baton style. The case is smooth and slightly smaller than the cases used on the later variants. To the best of my limited knowledge, this watch was only manufactured by Elgin. A question to the members of this forum: Is anyone aware of any other manufacturer of the A-13 other than Elgin?

The AN5740 variant utilized a slightly larger case with knurling on the outside edge of the case. (Consequently the back case cover from an AN5740 will not fit the earlier A-13 case and vice versa.) Functionally, the AN5740 was essentially identical to the A-13 except that it incorporated a black dial instead of the white dial used on the A-13. Additionally, the "AN" designated that the watch was to be jointly use by both the Army and Navy. To the best of my limited knowledge, this watch was only manufactured by Elgin. A question to the members of this forum: Is anyone aware of any other manufacturer of the AN5740 other than Elgin?

The AN5740-1 variant was similar to its predecessor, the AN5740, in that it also incorporated the black 24 hour dial with the following changes:
1. The minutes were marked from 5-60
2. The hours marked from 1-24.
3. "GCT" is marked above the center of the dial.
4. The hands were changed to a larger RR spade style.

The AN5740-1 was manufactured by Hamilton (140,000 watches), Elgin (20,000 watches), and Waltham (5,000 watches).

The following pictures illustrate the dial/hand variations from the A-13 (left) to the AN5740 (center) to the AN5740-1 (right). The attached Excel spreadsheet lists 7 Elgin watches that I have found on this forum which cover the A-13 through AN5740-1 variants. What is interesting in this very limited amount of data is that the earlier serial numbers also carried the marking on the movement of "U. S. Army A. C.". Additionally some of these Elgin movements were gold flashed while others were not.

The development of the master navigation watch has been an interest of mine. I have owned both a Hamilton and Elgin 5740-1 for some time. Earlier this year, I was lucky enough to acquire an Elgin A-13. Just this past week, I acquired an Elgin AN5740. Although as a rule, I limit my watch collection to American RR and Military variants, if I could ever find a Longines A-9, I would definitely have to try and add it to the collection.

Also, I should mention, that in the picture of the A-13 example below, it has a very unusual additional feature in that there are two hour hands, 6 hours apart, for tracking two time zones. This feature was discussed in the last link listed above. This is the only master navigation watch that I have come across that had two hour hands.

Richard

Dial 1.jpg Dial.jpg DSC02068.JPG
 

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Brad Maisto

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Richard,
I have two 24-hour dial watches, one is Elgin and the second is a Hamilton 4992B, 22 jewels with serial 4C83543 on the movement in a Keystone base metal case with the following well marked on the outside of the back case cover:
AN 5740
MFRS PART NO. 33106
SERIAL NO. AF43-22660
CONTRACT NO.
W535ac-40783
HAMILTON WATCH CO.
I have a picture of the black 24-hour dial and the "G. C. T." appears just like this below the "60" seconds and "24" hour rings, but my phone and iPad do not seem to be communicating right now, or my HughesNet internet sucks royally!
The base metal Keystone case middle ring has serial 0472998 and the back cover has serial 917446, either they were mixed up by the Naval Repairman or some one later?
My Elgin BWR is gold flashed and is serial 41,751,870. It is marked 21-jewels, Adjusted 5 Psitions, with TEMPERATURE below the small winding gear. The base metal case on the BWR is stamped cased and timed at the company and I cannot find a serial number stamped on the middle ting, but the back case cover has serial 81774.
Hope this is of some useful information, and if and when possible, I will add a picture of my Hamilton dial.
Brad Maisto
 

onsite

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Richard, see this The Military Watch Resource thread which contains a link titled here at the bottom of post #5,

As I read it the A-13 was made by Longines and Elgin but did not have the hack feature, the A-9 however did.

From the link:

Type A-13

The Type A-13 was a master navigation watch, similar to the Type A-9 except for incorporation of a start/stop feature. It was tested from September 1938 and standardized in May 1940. Changed to a limited standard in October 1941, and declared obsolete in November 1943. Longines-Wittnauer manufactured a Type A-13 GCT navigation watch in accordance with military specification 27968. Elgin manufactured a Type A-13 in accordance with military specification AN GG-W-108.

My Longines, #5734338, which I believe to be an A-13 was made on Mar. 10, 1939 (info from Longines).

The dial & hands could be better but it keeps perfect time.

The case appears to be correct yet does not have any military markings.

LGNS USAC Dial.jpg LGNS USAC Mvt. .jpg LGNS USAC Mvt. Close-up .jpg LGNS USAC Caseback .jpg LGNS USAC Case Mkg. .jpg LGNS USAC Bow .jpg

169
 
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grtnev

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Richard,
I have two 24-hour dial watches, one is Elgin and the second is a Hamilton 4992B, 22 jewels with serial 4C83543 on the movement in a Keystone base metal case with the following well marked on the outside of the back case cover:
AN 5740
MFRS PART NO. 33106
SERIAL NO. AF43-22660
CONTRACT NO.
W535ac-40783
HAMILTON WATCH CO.
I have a picture of the black 24-hour dial and the "G. C. T." appears just like this below the "60" seconds and "24" hour rings, but my phone and iPad do not seem to be communicating right now, or my HughesNet internet sucks royally!
The base metal Keystone case middle ring has serial 0472998 and the back cover has serial 917446, either they were mixed up by the Naval Repairman or some one later?
My Elgin BWR is gold flashed and is serial 41,751,870. It is marked 21-jewels, Adjusted 5 Psitions, with TEMPERATURE below the small winding gear. The base metal case on the BWR is stamped cased and timed at the company and I cannot find a serial number stamped on the middle ting, but the back case cover has serial 81774.
Hope this is of some useful information, and if and when possible, I will add a picture of my Hamilton dial.
Brad Maisto

Brad,

Thanks for the information.

Richard
 

grtnev

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Richard, see this The Military Watch Resource thread which contains a link titled here at the bottom of post #5,

As I read it the A-13 was made by Longines and Elgin but did not have the hack feature, the A-9 however did.

From the link:

Type A-13

The Type A-13 was a master navigation watch, similar to the Type A-9 except for incorporation of a start/stop feature. It was tested from September 1938 and standardized in May 1940. Changed to a limited standard in October 1941, and declared obsolete in November 1943. Longines-Wittnauer manufactured a Type A-13 GCT navigation watch in accordance with military specification 27968. Elgin manufactured a Type A-13 in accordance with military specification AN GG-W-108.

My Longines, #5734338, which I believe to be an A-13 was made on Mar. 10, 1939 (info from Longines).

The dial & hands could be better but it keeps perfect time.

The case appears to be correct yet does not have any military markings.

290177.jpg 290178.jpg 290188.jpg 290179.jpg 290180.jpg 290187.jpg

169
Thanks for the reply,

The 1st two pictures below are from pages 291 and 292 of Marvin Whitney's reference work Military Timepieces. (When I posted, the pictures posted out of order for some reason. Read the 2nd one first and the 1st one second. Sorry for the confusion - must have done something wrong on my end.) Whitney identifies the Longines Master Navigation Pocket Watch as being ca: 1939 which agrees with the information that you received from Longines for your watch.

Everything that I have read indicates that the Longines Master Navigation Watch carried the military designation A9 and was the first Master Navigation Pocket Watch to incorporate a "Start/Stop" (hack) feature via a slide mechanism on the outside diameter of the case at the 2 o'clock position. Refer to the 3rd and 4th pictures.

The Elgin A13 definitely does incorporate a "hack" feature. The Elgin A13 was the 1st Master Navigation Pocket Watch to incorporate the "Start/Stop" (hack) feature into the stem. Refer to the 5th picture from page 328 of Whitney.

According to Elgin Watch Company - Identification and Price Guide by Roy Ehrhardt, the 1st Elgin Grade 581 was serial number 39,261,001. The online Elgin Database identifies s/n 39,261,001 as being manufactured in 1940. If Elgin was the sole manufacturer of the A13 variant, than this also imply that the first A13 could not have been manufactured any earlier than 1940. Elgin used Grade 581 for their A13, AN5740, and AN5740-1 Master Navigation Pocket Watches with production running from 1940-1942.

Summarizing, as I understand the evolution and from the references that I have (including Whitney):
- the Longines A9 hacks via a slide mechanism
- the Elgin A13 and AN5740 hack via the stem
- the Elgin/Hamilton/Waltham AN5740-1 hack via the stem

On your watch, which I believe is a Longines A9, I don't see the start/stop slide mechanism. Could your watch have possibly been re-cased at some point in its history and in doing so, the "Start/Stop" (hack) slide mechanism was eliminated?

Something that was unique to the Longines A9, which I forgot to mention previously, was that it also incorporated a wind indicator at the 24 hour position - as does your watch.

Richard
 

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onsite

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On your watch, which I believe is a Longines A9, I don't see the start/stop slide mechanism. Could your watch have possibly been re-cased at some point in its history and in doing so, the "Start/Stop" (hack) slide mechanism was eliminated?


Richard

My watchmaker had it out of the case and there is/was no slide hack mechanism on this watch.

Assuming the stem hack simply stops the second hand when pulled out to setting position, it does not have a stem hack.

Could it be that this watch was made prior to the decision to incorporate the hack?
 

Brad Maisto

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Richard,
Christmas was kind to me so I can finally post a few pics of my two watches. Brad Maisto
P. S. Hamilton on the left and Elgin on the right in all three pictures.
IMG_0005.jpg IMG_0008.jpg
 

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terry hall

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Below are scans from Hamilton Mil contracts in reference to your above watch with contract W535AC-40783

I have NO idea if there are additional records at the NAWCC library or if these are in any particular order.
I reviewed 'quickly' about 40 pages looking for WC535ac-40783.
at least one page gives the specific data for the watch, how the case is to be marked, dial style, etc.

good luck.
 

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C. N. Lloyd

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{{A question to the members of this forum: Is anyone aware of any other manufacturer of the A-13 other than Elgin?}}

Bottom Line up front: I believe the A13 was manufactured by Elgin & Longines, which also agrees with the MWR website. As I do not collect foreign made watches I will leave the Longines A13 discussions to others. As far as the Elgin A13, here goes.

If we observe a strict interpretation of Marvin Whitney's comments regarding the definition of an A13, we are left with the call of a Master Navigation Watch with a white 0-23 dial as being the sole determinant of an A13. Mr. Whitney makes this reference in the Navigation Master Watch chapter of his landmark book, 'Military Timepieces'.

Elgin's original Navigation Master Watch was the grade 506, converted on an as-required basis to a 24 hour train and a white enamel 0-23 dial with a wind indicator. As to how many converted 506s are out there, I know not. You would have to see the procurement contract. All of the 506s will be late 30s production. The few I have seen may or may not have A13 or Navigation Master Watch on the cases; some have been seen in unmarked cases, some in plain cases with a single control number inscribed. Some serial numbers may indicate a similarly converted 494 - I do not think I have seen one, but the possibility is valid.

After the war began, Elgin made a Navigation Master Watch in the grade 544, with a total of 200 produced. 5 of the 6 544s (1 was in a misappropriated GF case) that I have ever seen all plainly say Type A13 Navigation Master Watch. 544s originally had the white 0-23 enamel dial, and, some are fitted with a wind indicator, some are not, although the 3 I have seen that were not WI examples did have the WI gear pinion holes. When it was determined to eliminate the wind indicator, Elgin began production of the 581, at first with the white enamel dial. And that is why I am in full agreement with Mr. Whitney as to what an A13 is: a Navigation Master Watch with a white dial. Neither Hamilton nor Waltham ever put white dials on their watches, so A13 production is out for them. To my knowledge, there have never been any claims of a Hamilton or Waltham marked A13.

{{ Is anyone aware of any other manufacturer of the AN5740 other than Elgin?}}

This one is more complicated, especially if we try and fit what we see into Mr. Whitney's definition, which I cannot. Going back to his definition in his book, the black 0-23 dial would be the AN 5740, and a black 1-24 dial is an AN 5740-1.

I differ from Mr. Whitney's stated premise in his definition of a mere dial change being the exclusive difference between an AN 5740 and an AN 5740-1. Based on what I and all the rest of us have seen over the years, black dials on all WWII contract watches are AN 5740s, regardless of an 0-23 or a 1-24 register.

I believe that Elgin, once awarded a contract for the AN 5740 with the new black dial (made of painted metal now, not enamel - and much cheaper to produce), merely reversed the colors of its standard A13 dial, without thinking much about it, and subsequently cranked up production again. You can be pretty certain that Elgin was authorized by the War Department to exhaust their supply of both white & black 0-23 dials, the dart type hands, as well as A13 marked cases, as Navigation Master Watches were considered an item of very critical issue status, shipments not to be delayed due to a benign or cosmetic difference from spec, and this appears to be the best explanation of those occasional sightings of the Elgin 581s with black 0-23 dials in A13 cases.

The Whitney AN 5740 definition does not fit the Hamilton 4992B or the Waltham 1622. Neither had an 0-23 dial on theirs, which, according to his premise, would mean that they are AN 5740-1s, and we all know that is not the case. From Hamilton's contracts in 1941, 1942, 1943, & 1944, Elgin's contracts from 1942 & 1943 - if any of you have a different year on your case, let it be known - and Waltham, with their single contract in 1944, only AN 5740 is marked on the cases - except for Elgin using up their A13 stock.

The only other exception I can think of right now is the 4 4992Bs I have run across over the years having a white enamel dial (like a 3992B 12 hour dial but without the MOD broad arrow) and a 12 hour train. Some out there will swear these are post-war conversions, but I think not. 3 of these 12 hour 4992Bs were in correct mil-spec base metal cases which were blank; 1 was in what looked to be a pieced together AN 5740 case. Just as a 3992B is a 12 hour train, it does not fit the A13 definition, and neither would these 12 hour 4992Bs. The post war conversion kits, as far as I know, all had painted metal dials, which are pretty easy to spot, even with less than stellar photographs, and all I have seen will either be in a war production case, inscriptions and all, or in a non-military case altered to accept the long stem. I do not buy the premise of some that Hamilton made these dials for civilian purchase, as there are several posts here showing factory bulletins stating that no 4992B replacement parts are being made for civilian sales.

The AN 5740-1 only begins to show up on the subsequent contracts after 1948, when the last WWII contract was fulfilled. Beginning in 1952, a new contract was let for Navigation Master Watches, with Hamilton again chosen to fill them, still calling the watch by its AN 5740 designation. However, all of the later contracts of 1956, 1958, and 1959 (these are the contract years I have seen) will either have the cases labeled AN 5740-1 or Navigation Master Watch with the 33106 part number, which replaced part number 4992B in 1943. Sometimes a reference will be given as 'type AN 5740', which indicates that no matter what the current spec code is for the watch, we want the same one like those.

It is my speculation, with nothing at all to back it up other than a military background in Field Artillery & Logistics, that the variation AN 5740-1 of the old WWII designation of AN 5740 came about on those post war contracts to ID a watch belonging to the USAF, and not to the USAAC. It has nothing to do with dials, hands, cases, components, or parts. The new AN 5740-1 designation signifies a new end user, and is likely for inter-service accountability and for future contract reference, because I can see immediately where the 5740 label would have created exponential panic within the bureaucratic cubicles tightly jammed inside the procurement building of things being ordered relating back to the USAAC, defunct since 1947.

Since government is by and large re-active to things, an order placed for AN 5740s would have been a likely red flag catalyst that would have convened a conference room meeting to expedite the -1 change order & associated paper trail adjustment to calm the nerves of the procurement minions, agonizing over subtracting the funds to pay for these watches from the now non-existent bank account of a now non-existent service branch. The new AN 5740-1 designation would solve all of the fiscal accounting shortcomings - while keeping the product otherwise unchanged. And what is functionally different about a 4992B made in 1941 from a 4992B made in 1959? That's right - nothing.

Some 4992Bs were ordered by the Navy Bureau of Ships for uses not affiliated with aerial operations. Those cases, while bearing the same old AN 5740 designation, will have a totally different contract engraved on the case: F.S.S.C. (Federal Service Supply Classification) R88-W510 or a derivative thereof, and a organizational SN beginning with the letter H. I have this contract number on watch cases marked both 5740 (low 4C#) & 5740-1 (high 4C#), which supports this premise, because the Navy was a part owner of the NMW venture anyway, and changing the designation will not affect them: their budget funding is still being approved by congress.

At least 1 contract was filled for the Army in 1942, for the Corps of Engineers. W145-ENG453 is the contract number on the case of mine; I do not know if the 453 is part of the contract or the organizational SN, as I have not seen another case marked like this one. These are probably those few 4992Bs that saw action in ground service operations, as the Engineer branch was a procurement and management point of contact for all sorts of off-the-shelf technical stuff just as the Quartermaster branch managed just about everything else.

I know this has been detailed, perhaps beyond your patience. But, I looked at it for 4 or 5 days, and this is the shortest answer I can come up with. Again, a lot of this is my speculation based on working in artillery for 15 years and logistics for 13 years, and for 1 of those years, having to depend on the reliability and efficiency of the products procured by those pigeon holed bureaucrats out where the metal meets the meat. A good bit of this speculation might be cleared up if one with access could locate and post the other contracts as Terry Hall has done for 40783. A big thank you, Mr. Hall.

A final word: military watch collectors know what we know, we try and fill in what we don't know with a logical extension that would fit in with what we do know. There are those out there who will say Hey, wait a minute, I have SN so & so and it is in a case marked so & so, ergo you are completely wrong. The one thing that we do know - if we know little else - is the sheer number of watches in wrong cases, especially Hamilton. So, match up your watch SN and see if it fits the reasonable man theory as to the case it is in. WWII contract watches go through 4C96082. Anything higher should properly be in a post-WWII contract case. Cases were not kept with the watch through the servicing line. Once the watch was serviced, it was put into any case handy with no regard as to whether the case was the one it was wearing when it came in. Fortunately, for Waltham & Elgin at least, their short stem design assured their replacement in a matching case, and the Elgin A13 case components will not interchange with the heftier AN 5740 cases.

C. N. Lloyd
38 years of pocket watch collecting
 

Jim Haney

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Two examples of the Military Elgins. The white dial is the A-13, Black Dial is AN-5740.



DSCN5251.JPG ] DSCN5250.JPG DSCN5249.JPG DSCN5248.JPG

DSCN5252.JPG DSCN5247.JPG DSCN5246.JPG DSCN5245.JPG DSCN5244.JPG DSCN5243.JPG

Both of these watches have the Hack feature.

White dial is # 39,516,133 and is Marked U.S.Army A.C.

Info on back of case is hard to read because the stamping is very light except for the AC263 triangle at the top. I am glad to see another example because I thought it had a replacement bow.

U.S. Army A.C.Watch Navagation Master Type A-13Ser. No. 41-826 Ord. No.W535AC-18210 Spec. No.94-27968 Mfg. Part No.1767 Elgin


Black dial is # 42,078,191 and movement is not marked.

Case back info is,

AN-5740 MFRS.Part No. 1790 Cont. No. W535-40-37880 Ser. No. AF- 43-9296
Elgin
 
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grtnev

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C. N.,

Thank you for your comments - a very informative analysis. I need to re-read and digest what you have written.


Jim,

Very interesting examples of odd 4992b dials. Thank you for sharing.


Just when I thought it was all beginning to make sense.....

Richard
 

Dave Chaplain

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Hi Jim - thank you very much for the photos of these military examples. One thing - I believe the dial shown here is not for the Elgin white dial example you hoped to show, but for a different Hamilton white dial example, which is also shown in your next post and described there as a Hamilton example.

Two examples of the Military Elgins. The white dial is the A-13, Black Dial is AN-5740.



290808.jpg ] 290810.jpg 290811.jpg 290812.jpg

290807.jpg 290813.jpg 290814.jpg 290815.jpg 290816.jpg 290817.jpg

Both of these watches have the Hack feature.

White dial is # 39,516,133 and is Marked U.S.Army A.C.

Info on back of case is hard to read because the stamping is very light except for the AC263 triangle at the top. I am glad to see another example because I thought it had a replacement bow.

U.S. Army A.C.Watch Navagation Master Type A-13Ser. No. 41-826 Ord. No.W535AC-18210 Spec. No.94-27968 Mfg. Part No.1767 Elgin


Black dial is # 42,078,191 and movement is not marked.

Case back info is,

AN-5740 MFRS.Part No. 1790 Cont. No. W535-40-37880 Ser. No. AF- 43-9296
Elgin
 

Fred Hansen

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Agassiz made a WWII era military wind indicator, anyone know what markings it carried?
 

Jim Haney

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Hi Jim - thank you very much for the photos of these military examples. One thing - I believe the dial shown here is not for the Elgin white dial example you hoped to show, but for a different Hamilton white dial example, which is also shown in your next post and described there as a Hamilton example.
Dave,
Thanks for pointing this out. I guess when up loading the pictures that day, the tiny icons of the white dials all looked the same.

This is the Elgin dial


DSCN5263.JPG
 

Fred Hansen

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Great watch Dave! Are there any markings on the case back?
 

Dave Chaplain

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Fred, no markings on the rear of the stainless steel cases "as made", as far as I can tell. Which is the same for the few I've seen (maybe 5 in total) after looking for some time. Two other movements are numbered close to mine and share the same (Touchon ebauche?) top plate layout (three in total). And two others are from a number series about 15K higher than mine and have a common but different bridge layout. All of the case numbers are either the same or very close to the movement numbers (I saw one that was off by one number), with plain back finish. Of those I've seen, two have a rectangular and seemingly functional hack seconds button on the side of the case, and three look to have the rectangular hack spot filled and disabled. Mine also has an owners name engraved on the rear of the case - Leo Estes. I found a Navy man named Leo Estes at the Naval Air Station Pensacola in 1941-42, and on the carrier USS Saratoga in 1945. But that's as far as I've got.

Here are pics of my (not cleaned) case and cuvette snap backs covers:
sn 226969 21j inner case3 GCT 24-hour.jpg sn 226969 21j outer case3 GCT 24-hour.jpg
(the dark spot/matrix on the case back were caused by a rubber-like shelf storage material that the case was lying on. It'll clean off, but still ... :/ )
 
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Dave Chaplain

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The Agassiz GCT sn's seen:

with Touchon ebauche, marked Agassiz Watch Co. Twenty-One 21 Jewels Adjusted Temperature AXA Swiss:
226881
226940
226969

and with a more standard bridge layout, marked Agassiz Watch Co. Twenty-One 21 Jewels Adjusted Temperature AXA Swiss:
237531
237628

I'd cite the source of the 2nd pic, but don't remember where it was retrieved from the internet ...

sn 226969 21j mvmt3 GCT 24-hour.jpg sn 237531 mvmt 3593958487_IMG_9484.jpg

Also, the dials are the same on all examples.
 
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Fred Hansen

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Thanks Dave, great info. I've always admired these but haven't studied them closely. I'll keep an eye out for additional examples and post back with any I see.
 

grtnev

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{{If we observe a strict interpretation of Marvin Whitney's comments regarding the definition of an A13, we are left with the call of a Master Navigation Watch with a white 0-23 dial as being the sole determinant of an A13. Mr. Whitney makes this reference in the Navigation Master Watch chapter of his landmark book, 'Military Timepieces'.

Elgin's original Navigation Master Watch was the grade 506, converted on an as-required basis to a 24 hour train and a white enamel 0-23 dial with a wind indicator. As to how many converted 506s are out there, I know not. You would have to see the procurement contract. All of the 506s will be late 30s production. The few I have seen may or may not have A13 or Navigation Master Watch on the cases; some have been seen in unmarked cases, some in plain cases with a single control number inscribed. Some serial numbers may indicate a similarly converted 494 - I do not think I have seen one, but the possibility is valid.

After the war began, Elgin made a Navigation Master Watch in the grade 544, with a total of 200 produced. 5 of the 6 544s (1 was in a misappropriated GF case) that I have ever seen all plainly say Type A13 Navigation Master Watch. 544s originally had the white 0-23 enamel dial, and, some are fitted with a wind indicator, some are not, although the 3 I have seen that were not WI examples did have the WI gear pinion holes. When it was determined to eliminate the wind indicator, Elgin began production of the 581, at first with the white enamel dial. And that is why I am in full agreement with Mr. Whitney as to what an A13 is: a Navigation Master Watch with a white dial. Neither Hamilton nor Waltham ever put white dials on their watches, so A13 production is out for them. To my knowledge, there have never been any claims of a Hamilton or Waltham marked A13.........

Going back to his [Whitney's] definition in his book, the black 0-23 dial would be the AN 5740, and a black 1-24 dial is an AN 5740-1. I differ from Mr. Whitney's stated premise in his definition of a mere dial change being the exclusive difference between an AN 5740 and an AN 5740-1.

Based on what I and all the rest of us have seen over the years, black dials on all WWII contract watches are AN 5740s, regardless of an 0-23 or a 1-24 register. I believe that Elgin, once awarded a contract for the AN 5740 with the new black dial (made of painted metal now, not enamel - and much cheaper to produce), merely reversed the colors of its standard A13 dial, without thinking much about it, and subsequently cranked up production again. You can be pretty certain that Elgin was authorized by the War Department to exhaust their supply of both white & black 0-23 dials, the dart type hands, as well as A13 marked cases, as Navigation Master Watches were considered an item of very critical issue status, shipments not to be delayed due to a benign or cosmetic difference from spec, and this appears to be the best explanation of those occasional sightings of the Elgin 581s with black 0-23 dials in A13 cases.

The Whitney AN 5740 definition does not fit the Hamilton 4992B or the Waltham 1622. Neither had an 0-23 dial on theirs, which, according to his premise, would mean that they are AN 5740-1s, and we all know that is not the case. From Hamilton's contracts in 1941, 1942, 1943, & 1944, Elgin's contracts from 1942 & 1943 - if any of you have a different year on your case, let it be known - and Waltham, with their single contract in 1944, only AN 5740 is marked on the cases - except for Elgin using up their A13 stock.

The AN 5740-1 only begins to show up on the subsequent contracts after 1948, when the last WWII contract was fulfilled. Beginning in 1952, a new contract was let for Navigation Master Watches, with Hamilton again chosen to fill them, still calling the watch by its AN 5740 designation. However, all of the later contracts of 1956, 1958, and 1959 (these are the contract years I have seen) will either have the cases labeled AN 5740-1 or Navigation Master Watch with the 33106 part number, which replaced part number 4992B in 1943. Sometimes a reference will be given as 'type AN 5740', which indicates that no matter what the current spec code is for the watch, we want the same one like those.

It is my speculation, with nothing at all to back it up other than a military background in Field Artillery & Logistics, that the variation AN 5740-1 of the old WWII designation of AN 5740 came about on those post war contracts to ID a watch belonging to the USAF, and not to the USAAC. It has nothing to do with dials, hands, cases, components, or parts. The new AN 5740-1 designation signifies a new end user, and is likely for inter-service accountability and for future contract reference...

C. N. Lloyd
38 years of pocket watch collecting

After further study, I believe that Mr. Lloyd has pretty much nailed it and that the descriptions that I offered earlier, based primarily on Whitney as the prime reference are in error.

Mr. Lloyd states: "The AN 5740-1 only begins to show up on the subsequent contracts after 1948, when the last WWII contract was fulfilled. Beginning in 1952, a new contract was let for Navigation Master Watches, with Hamilton again chosen to fill them, still calling the watch by its AN 5740 designation. However, all of the later contracts of 1956, 1958, and 1959 will either have the cases labeled AN 5740-1 or Navigation Master Watch with the 33106 part number".

From what I have been able to ascertain, AN5740 was revised twice with the 1st revision; i.e. AN5740-1 dated 15 March 1957. Consequently, as Mr. Lloyd stated, "the later contracts of 1956, 1958, and 1959 will either have the cases labeled AN 5740-1 or Navigation Master Watch with the 33106 part number".

1. First revision: Document Number:AN5740 rev 1
Publish Date: 1957-March-15
Organization: Naval Surface Warfare Center (NSWCIHEODTD)

2. Second revision: Document Number: AN5740 rev2
Publish Date: 1961-April-25
Organization: Naval Surface Warfare Center (NSWCIHEODTD)

What is still not clear to me is the difference between:
an Elgin A-13 (WHITE 0-23 hour, 0-55 minute dial and dart type hands with the smaller, smooth outside diameter A-13 type case), and
the Elgin variant with a
BLACK 0-23 hour, 0-55 minute dial and dart type hands with the smaller, smooth outside diameter A-13 type case.

The only difference between these two watches is the color of the dial and hands; i.e. white (A-13) vs. black (A-13 variant?) Please refer to the pictures below. Pictures 1 and 2 are the white dial A-13. Third picture is the black dial variant.

To further confuse the issue, I found an example of the black dial variant on line where the description states: "Black face has luminous dial with 24-hour time interior and outer rim designated in seconds. Reverse has AN proof stamp and military nomenclature designation "TYPE A-13"........." Refer to the fourth picture (far right). There is no way to absolutely know that the case and watch in the last picture were originally together. However, it does raise the question...did Elgin make both a white dial and black dial variant of the A-13? I have not been able to find Military Specification 94-2796 for the A-13. If anyone has access to a copy of this spec and can post it as a part of this thread, it would be much appreciated.

Summarizing, I agree with Mr. Lloyd's observations and conclusions except for one remaining question that I raise at this time. Did Elgin produce both a white dial and black dial variant of the A-13? It would make more sense to me that both the white dial and black dial variants shown below are both A-13's since the only differences between the two are dial and hand colors; whereas there are significantly more differences between the watches shown below and an AN 5740 as previously discussed (different dial markings, different style hands, larger case, etc.).

Is the example in the fourth picture (below right) accurate; i.e. black dial variant watch being described as having the case marked A-13?

For reference:
Pictures 1 and 2, below left; Elgin A-13 (white dial) is s/n 40500199, non gold-flashed movement, ca: 1941, movement marked U.S. Army A. C.
Picture 3, the Elgin black dial variant is s/n 40470345, gold-flashed movement, ca: 1941, movement marked U.S. Army A.C. (This is also interesting in that the black dial variant was produced prior to the white dial A-13. Question is, is it also an A-13?)

Richard
 

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C. N. Lloyd

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Richard, to speculate along with you, I cannot discount your black dial A13 theory. The white dials would have almost certainly been changed out for the black dials in the instance of being brought in for service or repairs, as the new spec called for black dials. I can say I have never seen a black 0-23 Elgin in a AN5740 marked case, but I have only seen probably 200 or less Elgin NMWs anyway, compared to maybe a thousand 4992Bs. So, I would not argue against your black dial A13 premise without more evidence to discount it. However, this would run the risk of having a 1-24 dial on some of these early runs, which I do not recall ever having seen - unless the 0-23 dials were packaged in A13 labeled tins, and the 1-24 dials in AN5740 tins.

Since posting my previous in January, I have recorded a 1957 contract on a Hamilton, marked DA-36-038-ORD-20108. The case was just too chewed up (for me) for consideration.

Also Richard, in your locating those change orders, is MS 28076 mentioned? I have a hand-written note that AN5740-1 changed to this MS (Military Specification) number in March 1957, but could not source the information when I wrote it down. For the record, I do have this MS number on a couple of my later 4992Bs, SNs of over 4C130xxx. The final contracts list a DAAA25 code, followed by a organizational SN with the year being the 1st 2 digits. I have one marked DAAA25 {68-0066}, and have seen one like it with a 1967 date. Both have an over 4C140xxx SN. The only thing I can conjure up for a definition is Dept. of Air / Army Aeronautics, but, who knows.

For those who can (and care to) access Hamilton records for war contract information, I can provide this contract list:

USAAC
W535 ac 20872 (1942)
W535 ac 22375 (1942)
W535 ac 40783 (1942 & 1943) posted January 2017 in this thread by Terry Hall
W535 ac 86366 (1943)

USA
W145 ENG - This is the order filled for the U.S. Army, which were probably the ones used in ground service operations. After having seen another recently, I can now confirm the number to the right of ENG will be the organizational SN of the watch. Both watch SNs were in the 4C6xxx range.

USAF
DA-36-038-ORD - 9702 (1952)
DA-36-038-ORD - 9888 (1952)
DA-36-038-ORD - 19668 (1956)
DA-36-038-ORD - 20108 (1957)
DA-36-038-ORD - 21409(M) (1958)
DA-36-038-ORD - 20872 (1959) - 20872 was also a WWII contract, so, proceed with caution.

The posting of these contracts would go a very long way toward determining what would be a correct case for the movement. However, bear in mind that these contracts will not account for all of the watches. There were, in addition to the contracts, Orders and P.Os. (probably Purchase Order) that appear to be placed on the case in orders of just a few watches. Exactly what constitutes 'a few' I have no idea, but I would think maybe orders of 100 or less, although I may be completely wrong. There are also instances of single purchases, which if to a general or flag officer, may account for many of the blank cases out there. This is why locating the contracts would be so enlightening for us military watch collectors.

C. N. Lloyd
38 years of pocket watch collecting
 

Dave Chaplain

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Hopefully this will add something to the discussion so far ... the attached photos show a Waltham 16-A / 1622 with a black 24-hr dial, and with the movement marked:

16-A Waltham U.S.A. 22 Jewels Adj. Temp. 3 Pos.

And with the case marked:

AN 5740 MFRs PART NO 1622-S-24-C CONTR NO W-11-107Ac-581 SER NO AF-44-937 Waltham

300764.jpg 300765.jpg
 

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Dave Chaplain

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And one more Elgin 0-23 black dial example, with the movement marked:

B.W. Raymond 21 Jewels Adjusted 5 Positions Temperature U.S. Army A.C., E.N.W.Co. U.S.A. (under bal)

And with the case marked:

Type A13 Spec. No. AN-GG-W-108 Ser. No. AC42-4781 Mfrs. Part No. 1786 Ord. No. W535AC-2807 Elgin

attachment.jpg attachment.jpg
 

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grtnev

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Also Richard, in your locating those change orders, is MS 28076 mentioned?
I found the references to the two revisions of AN 5740 at the following links: http://standards.globalspec.com/std/50223/navy-an5740-rev-1 and http://standards.globalspec.com/std/83611/navy-an5740-rev-2-canc. Unfortunately you have to subscribe to the service to get access to the actual documents to get a copy of them - which I haven't done - hoping someone on the forum may have access to them.

One other point of interest. I found a 2nd "black dial" A-13, s/n 40470346, at the following link: https://pocketwatchdatabase.com/profile/rightintool/collection/view/62499
On the case back of that watch, the referenced specification is: SPEC NO. AN-GG-W-108 and the watch is marked "A-13"

In my post five above this one, I show a white dial A-13 (s/n 40500199), which is a watch that I own. On the case back, the referenced specification is: SPEC NO 94-27968

Whitney states that: "Master Navigation Watch Army-Navy Aeronautical Specification AN-GG-W-108, dated August 6, 1941, superseded the current issue of U.S. Army Specification 94-27968...."

In my notes, I have the picture below as the dial configuration for SPEC NO. AN-GG-W-108. The dial configuration shown is for AN 5740. However, the case back of the previously mentioned 2nd black dial A-13, s/n 40470346, in addition to being marked A-13, is also marked SPEC NO. AN-GG-W-108:???:

Does this imply that somehow SPEC NO. AN-GG-W-108 applied to both black dial variant master navigation watches; i.e. "A-13 with black dial and white hands" as well as AN-5740?

I think we pretty much all agree/understand what a white dial A-13 manufactured by Elgin is; as well as a black dial AN-5740 manufactured by Elgin, Hamilton, and Waltham.

Dave Chaplain, in the post just above this one, shows s/n 40470553 and states that the case is marked as A-13 and SPEC NO AN-GG-W-108. Additionally, I have found two examples on line which depict a black dial/white hand variant marked A-13. This suggests that the black dial, white hand variant of the A-13 was indeed a reality. That being said, it would be nice to find this configuration in a specification somewhere.

Richard 300812.jpg
 

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River rat

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Here is my Elgin. If you notice they took a off the shelve BW Raymond since there's 21 jewel instead of 22 jewel on the movement my guess is they were in a hurry to get these out in the beginning of production on this one. Good thread you wrote.
032.jpg

049.jpg
 

Leigh Callaway

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On page 325 of "Military Timepieces", Whitney notes "The earlier [Elgin GCT] movements were marked 21 jewels. However they carried 22 jewels, the additional one being found in the sweep second pinion bridge."

I have one - bought 20 years ago at an antiques show in Maryland. The dial had been doctored to show PM hours. Here is a photo of the dial during and after cleanup.

301927.jpg 301928.jpg

Not pristine, runs just fine.
 

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Jim Haney

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Some pictures of the Elgin AN5740-1.The case back has the last 5 numbers of the serial number which is 41758536.

This watch was for an English contract , most likely in the late 1950's .

Out of the total production of 20,000 Grade 581's these last ones (AN5740-1) were very few.

They went to the Hydrographic Dept. at Herstmonceux Castle near Hailsham, Sussex.


315348.jpg
315349.jpg
315350.jpg
315351.jpg
315352.jpg
315353.jpg
315354.jpg

From what I can understand, only the dials made the difference between these 3 watches.

A-13
AN-5740
AN-5740-1

315356.jpg
315357.jpg
315358.jpg
 

Jim Haney

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Another style dial for the 4992B. These should go with my post #13 dials.

Looks like a Hamilton dial with the right fonts in the lettering and has some scratched letters on the back.

Doesn't appear to be swiss or repo.

DSCN6163.JPG DSCN6162.JPG DSCN6159.JPG DSCN6160.JPG
 

musicguy

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Interesting white second sweep hand on white dial.

Rob
 

musicguy

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Jim Haney

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Another different style dial on a 4992B watch.
The dial is divided by 300ths.
The case number match and it would be interesting to see if the contract number specified this dial or for that matter any of the different dials from posts 13,& 35.

DSCN6646.JPG DSCN6645.JPG DSCN6649.JPG DSCN6647.JPG DSCN6648.JPG
 
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musicguy

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Some of the numbers on the inside register look to be hand drawn(like the 16)
others don't. Very interesting dial. Nice!

Rob
 

musicguy

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I was asked if the back of the case matches the case and movement(just thought I would post answer here too).
the three roman numerals on the case under the front bezel
do match the last three digits on inside back of the case.


Rob
 

Jim Haney

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I am going to tag this on to this tread because it is related.

This is a GCT watch or some kind. It is a Elgin 581 with the Broad-arrow mark and in a wooden box with a good fitting leather lining.It keeps the watch tight in place.

Richard has given me info on the Hydrographic Dept before and maybe he can I.D. this one.

It is NOS condition. Has Ser. No 729 on the case back and has Ser. No.805 in the case? Neither number match and serial numbers on the movement or case.

This watch was in the last run of Grade 581 and was made in 1942. Serial # 42078716

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Leigh Callaway

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Jim Haney

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Lee,
Thanks very much for the links & the chart on the HS Chart.

I would say that my watch was a H.S. 3 However it is missing any ID on the case back other than a Serial number 729.

The plate inside the box does say "Watch Deck" so that is what it is.
 

Jason Herron

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I recently came across an A-13 model made by Longines-Wittnauer. Does anyone have any info on it to help me out? Sorry I know pictures are not the best quality.
Thanks
Jason

C5336DAE-3A11-423B-877F-41156A5FB9C9.jpeg 572AF7A5-51ED-443E-804D-F471A187CDC8.jpeg E2F9C68C-368E-414C-8B98-57C40EA5CFE1.jpeg
 

musicguy

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Jason Herron

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Thank you for getting back to me. Is there a specific type of aircraft these would have been used on? Also, is the Longines model more rare than the Elgin? Do you know how to get inside to see the serials number? I was able to get the glass off but then I got a little nervous. I don’t know much about watches and did not want to break anything. Sorry for all of the questions but I find this piece very interesting!
Thanks,
Jason
 

musicguy

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Sorry for all of the questions
You can never ask too many questions, that's why this educational site is here!

I believe the back lid should screw off. You shouldn't hurt it
by opening it up.

The Master Navigation watch was designed to be the master timepiece for aircraft navigation in the same way a
chronometer is used for shipboard navigation.

G. C. T. Greenwich Civil Time (later Greenwich Mean Time)

Rob
 

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