23890

The chromium-plated nickel, open-face case has the winding/setting crown inset into a wide pendant with a flat, shaped bow. Pulling out the winding button stops the watch (light spring against the balance) and engages the handset facility. The convex 'unbreakable' glass is held in a screw-down, knurled, chromium-plated nickel bezel. The nickel, screw-down back is machine engraved on the back 'WATCH / NAVIGATION MASTER / MS 28076 / MFR'S 33106 / DA-36-038-ORD-21409-M / SERIAL NO. 23890 / HAMILTON WATCH CO. / U.S.N'. The inside of the back is stamped with the case manufacturer's mark 'STAR WATCH CASE CO.', a star, 'BASE METAL' and 'P000894'.

A matt-black dial of 43 mm Æ is marked 'G.C.T.' (Greenwich Civil Time) above the centre. The 24-hour dial has vertical Arabic numerals with small vertical Arabic five-minute figures round the outside. White-painted, steel spade and poker-hands have a counter-balanced, white-painted steel centre seconds hand.

The going barrel, barred movement is of bright, damascened nickel and is signed with black enamel-filled engraving on the barrel bridge 'HAMILTON / WATCH CO. / U.S.A' and 'ADJ. TEMP. / AND 6 / POSITIONS'. The escape/fourth wheel bridge is marked '4992 B / 22 / JEWELS'. It is also marked on the main plate, by the balance cock foot '4C138538'. A polished steel index mounted on the balance cock acts on a lateral screw for fine rating adjustment. The index has a scale under it engraved with 'F' and 'S' for fast and slow. There is a four-wheel train with a centre seconds drive off the third wheel and a going barrel.

There is a double roller, jewelled and club tooth lever escapement. The impulse roller has a clear jewelled impulse pin and pallets with clear stones. The pallets bank against brass banking pins. The uncut balance is mounted with 20 brass screws around the rim. The flat spiral 'Hamilton Elinvar Extra' balance spring with over coil has an index mounted on the upper surface of the balance cock. The train is jewelled to the centre (22 jewels in total) with red stones in brass press-in settings and the balance and escape wheel have end stones.

The instrument is in good condition. There are slight rust spots on index.

The serial number on the box and case (23890) should be the same as Hamilton's serial number for this '4C' calibre movement (i.e. 4C23890). The fact that the movement now in the case is serial number 138538 is almost certainly as a result of movements (all interchangeable with Hamilton material) becoming switched during overhauls.

Object Details

ID: ZAA0556
Collection: Timekeeping
Type: Deck watch
Display location: Not on display
Creator: Hamilton Watch Co
Date made: circa 1942
People: Harries, David H.
Credit: National Maritime Museum, Greenwich, London
Measurements: Overall: 65 x 52 x 17 mm