Original Items: Only One Set Available. As used by navigators on B-17 Flying Fortress and B-24 Liberator this is a FULLY FUNCTIONING Hamilton AN5740-1 pocket watch from the Vietnam War era.

This is a very good example of the Hamilton U.S Army Air Force GCT Navigation watch type AN 5740-1, with a manufacture date of 1959. The "GCT" or AN 5740/AN 5740-1 pocket watches were used for navigation purposes by all the branches of the US. Military prior to, during, and after WWII. The three main manufacturers of the AN-5740 and AN-5740-1 were The Hamilton Watch Co., The Elgin National Watch Co. and the Waltham Watch Co.

This watch is in very nice condition, with a great deal of the original finish present. It is fully functional and intact with all original markings.

This watch is marked as follows:

Dial Markings:

G.C.T
Back Case Markings:
AN 5740-1
STOCK NO. 6645-663-7694
MFR’S PART NO. 33106
CONTRACT NUMBER
DA-36-038-ORD-20782(M)
SERIAL NO. AF-59-21660
HAMILTON WATCH
COMPANY

Movement markings:

HAMILTON
WATCH CO.
USA
4922B
22
JEWELS
ADJ.
TEMP.
AND 6
POSITIONS
4C137468

The 59 in the serial number denotes a manufacture date of 1959, perfect for the Vietnam War period.

There is no warranty for this watch and returns for a non-working watch will not be honored. Please note all watches are wound and tested then recorded on video before shipment. We are not in the watch repair business- ALL SALES ARE FINAL.

WWII & Later Navigation Pocket Watch History
During World War II, Hamilton, Waltham, & Elgin produced a variety of time pieces to support the war effort. In fact, all of Hamilton's production was dedicated to defense purposes. However, they did still produce some wrist watches using excess movements produced in the 1920's.

One of the war-related watches was a pocket watch with a central sweep second hand. The movement was based on the 21 jewel, 16 size movement. However, an extra jewel was added to support the second hand pinion, so the movement got 22 jewels.

Known as a "Navigator's Watch" as it was used by aviators to aid in navigation by the US Navy during the war. You'll notice a couple of advertisements from WWII-era Life Magazines that featured the 4992B. You'll often see these in a case or a box that was intended to isolate it and protect it from shocks or accidental damage.

If you look closely at the dial, you'll see that it's a 24 hour dial so it takes a full day for the hour hand to make a full rotation. 12:00 noon on a 24 hour dial looks like 6:00 on a 12-hour dial. The minute hand still makes it around the dial in one hour, so the ratio of the minute hand to the hour hand is modified using a different minute wheel and hour wheel ratio.

Another interesting aspect to this watch is that it "hacks" or stops when you pull out the crown to set the time. This allows you to set a very precise time... the old, "synchronize your watches" phrase comes to mind. Genuine WWII Navigator's pocket watches in such excellent fully functional condition tremendously rare!