{"product_id":"original-wwii-usaaf-1943-hamilton-an5740-g-c-t-navigator-pocket-watch-with-carry-case-1","title":"Original WWII USAAF 1943 Hamilton AN5740 G.C.T Navigator Pocket Watch with Carry Case","description":"\u003cp\u003eOriginal 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 pocket watch with steel carry case.\u003c\/p\u003e\n\u003cp\u003eThis is a FULLY FUNCTIONING beautiful 1943 produced example of the Hamilton U.S Army Air Force GCT Navigation watch type AN 5740. 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.\u003c\/p\u003e\n\u003cp\u003eThis watch is marked as follows:\u003c\/p\u003e\n\u003cp\u003eDial Markings:\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eG.C.T\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eMovement markings:\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eHAMILTON\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eWATCH CO.\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eUSA\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003e4922B\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003e22\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eJEWELS\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eADJ. TEMP.\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eAND 6\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003ePOSITIONS\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003e4C82538\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eRear case nomenclature:\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eAN 5740\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eMFR'S. PART NO. 33106\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eSER.NO. AF-43-21765\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eCONTRACT NUMBER:\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eW535 ac- 40783\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eHAMILTON WATCH CO.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eChrome finish of the watch is in very good condition. The steel case with glass window and rotation door, is marked with a brass data plate that reads:\u003c\/p\u003e\n\u003cp style=\"text-align: center;\"\u003e\u003cstrong\u003eCASE, CARRYING, WATCH\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eNAVIGATION\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eU.S. ARMY A.C.\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eGEO. H. ADAMSON\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cstrong\u003eTECUMSEH, MICHIGAN, U.S.A.\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe case was designed to suspend the watch to protect it from the vibration and turbulence of an aircraft as well as a protective glass viewing panel to the user could look down onto it without removal.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWWII Navigation Pocket Watch History\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003eDuring World War II, Hamilton, Waltham, \u0026amp; 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.\u003c\/p\u003e\n\u003cp\u003eOne 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.\u003c\/p\u003e\n\u003cp\u003eKnown as a \"Navigator's Watch\" as it was used by aviators to aid in navigation by the US Navy during the war.\u003c\/p\u003e\n\u003cp\u003eYou'll notice a couple of advertisements from WWII-era Life Magazines that featured the 4992B.\u003c\/p\u003e\n\u003cp\u003eYou'll often see these in a case or a box that was intended to isolate it and protect it from shocks or accidental damage.\u003c\/p\u003e\n\u003cp\u003eIf 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.\u003c\/p\u003e\n\u003cp\u003eAnother 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.\u003c\/p\u003e\n\u003cp\u003eGenuine WWII Navigator's pocket watches and cases in such excellent fully functional condition tremendously rare!\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eThere 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.\u003c\/strong\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003c\/p\u003e","brand":"Original Items","offers":[{"title":"Default Title","offer_id":41170077352005,"sku":"ONAC240036","price":1395.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1524\/1342\/files\/ONAC240036__01.jpg?v=1711129710","url":"https:\/\/www.ima-usa.com\/products\/original-wwii-usaaf-1943-hamilton-an5740-g-c-t-navigator-pocket-watch-with-carry-case-1","provider":"International Military Antiques","version":"1.0","type":"link"}