The mechanical general service watch was initially manufactured for CWC by the Hamilton factory, and is identical to the preceding watches from Hamilton that had been issued from 1973 until 1975. These watches had been based on an updated Defence Standard that had been published in 1971 picturing the tonneau-shaped case, and had in turn replaced the Smiths watch which had been issued from 1967 to 1970,
Around 24,000 CWC watches were issued by the British Army in 1976, 1977, 1979 and 1980 – of which 10,000 were issued in 1976 – with smaller numbers issued by the RAF in 1979 and the Royal Navy from 1977 to 1979. This preponderance of W10-marked examples is what gives the watch its name.
There are two styles of 0552 marked watches - the 1977 batch has the NSN marked 0552-523-8290 all in one line, whilst the 1978 and 1979 batches have 0552 on one line, and 523-8290 on the line below. Pictures of some of the 0552 watches can be found here.
The dial design is identical across all these watches; the CWC logo and a circled T above the hands, and the broad arrow below the hands, luminous indices and a luminous triangle at 12 o'clock, SWISS below the 6 index, and white numerals. The hour and minute hands are tritium lume-filled and the seconds hand is white. The movement is the ETA2750 with hacking (ability to stop the seconds hand for precision time setting), and the case is a monocoque (one piece) construction.
In addition to the British military-issued watches, two other variants have been seen, issued by overseas militaries; a watch with an O in place of the Service code issued by the Sultan of Oman's Land Forces in 1979 and 1980; and a watch with a shortened NSN and KK either side of the broad arrow issued in 1977, the issuing authority of which is currently unknown.
The dial, hands and case remained identical throughout the 5 years that the watch was produced.
ETA 2750 movement, marked CWC on the main movement bridge.
Monocoque (one-piece) case, marked SWISS MADE and CWC.
1979 was the only year when all three Services issued the W10. Photo Credit: Ed875 on MWR.
"KK" marked watch from 1977, next to a standard W10 1977 watch. Note the shortened NSN.
"O" marked Omani-issued watch from 1980 with a W10 from 1980. Note slightly larger text for the NSN on the "O" watch.