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Hamilton Watch Co. was in operation from 1892-1969 and manufactured some of the highest end, most accurate watches ever produced. Manufacturing of Hamilton watches took place at their facility in Lancaster, Pennsylvania.
Manufactured in 1946 in the immediate postwar period, this Hamilton Model 23 AN-5742-1 was produced for the U.S. Army Air Forces as a purpose-built air navigation chronograph. Unlike civilian chronographs of the era, the Model 23 was engineered specifically to military specification as a timing instrument for navigators, where precise interval measurement was critical for dead-reckoning navigation, position fixes, and coordinated flight operations. These watches were used by navigation crews aboard long-range aircraft such as the B-17 Flying Fortress, B-24 Liberator, and B-29 Superfortress, where accurate interval timing was essential for course correction, fuel management, and coordinated mission execution. The watch is powered by Hamilton’s 19-jewel Model 23 chronograph movement, featuring a large center seconds hand with flyback chronograph function and a 30-minute register, allowing rapid reset and repeat timing without stopping the movement. Accuracy and legibility were prioritized throughout the design, from the robust balance and temperature-stable regulation to the oversized dial layout intended for low-light cockpit use. Every component of the movement has been fully serviced and hand restored in our Little Rock, Arkansas workshop. The plates were carefully cleaned and revived, jewel settings were individually polished to restore their original golden tone, and the balance and balance weights were refinished to their factory luster, creating strong visual contrast against the nickel-finished bridges. All visible elements remain original, including the dial, hands, and case. To our knowledge, this is one of the only Model 23 chronographs restored with enamel lettering executed at this level, making it a genuinely unique example among surviving Model 23s. The bold white Arabic numerals and high-contrast chronograph scale deliver exceptional clarity, while the original white painted hands retain their correct factory finish. Housed in its original case engraved with the military issue designation “AN-5742-1,” this Model 23 represents one of the most specialized and historically important American navigation chronographs ever produced. Fully serviced and mechanically restored, it is ready to be worn, displayed, or preserved as a serious instrument of U.S. aviation history.
Watch Performance
Accuracy: +/- 10 seconds per day
Amplitude: 275 degrees
Beat Error: 0.4 ms
Frequency: 18,000 (5 beats per second)
Power Reserve: 24-30 hours
Complication: Chronograph
Watch Specifications
Manufacture: Hamilton Watch Company
Partnership: US Military during WWII
Location: Lancaster, Pennsylvania
Year Manufactured: 1946
Dial Material: Metal
Movement Setting: Stem
Jewels: 19 jewels
Jewel Casings: Brass (hand restored)
Warranty: Full 1-Year Warranty
Case Diameter: 50 mm
Height: 14 mm
Original Case Included: Yes, military issued
Serial Number: P25639
All Frett & Co. Clockworks watches come with a full 1-year warranty unless otherwise stated.