GPO impulse (slave) wall clock No. 4a with George VI cypher, circa 1950

This large and impressive wall clock, designed for use in GPO offices and exchanges, did not have its own power source but operated on an electrical impulse generated every 30 seconds by a master clock - hence the term ‘slave’. The master clock would be wired to a number of slave clocks, ensuring accuracy and consistency across the network.

The clock features a very substantial octagonal bakelite case, moulded by H E Ashdown Limited of Birmingham, which was introduced in 1949 superseding the earlier round wooden cases. The clock is very heavy, with an enamelled steel dial weighing 700g secured to an 800g steel falseplate mounted in the 1.5kg case. The clock also has 1/8 inch (3mm) flat glass, a painted spun brass sight ring and counterbalanced aluminium hands.

This is an early, undated example circa 1950. The mottled red-brown bakelite case is in excellent condition with no damage. The dial shows some slight foxing and a few slight blemishes but there is no loss. The glass is clear and unmarked. The original pulse movement (which could not operate without a master clock or other pulse generator) has been replaced with a high quality German UTS quartz movement. The hands are original to the clock and have been re-colleted to fit the arbors of the new movement.

The clock has been fully disassembled, cleaned and sensitively restored as appropriate. It is supplied in outstanding overall condition and full working order (it  takes a single AA battery).

Movement type

Quartz battery

Dimensions

Dial diameter 12 inches (305mm); width across flats 430mm; depth 82mm. Weight 3.7kg

SOLD

but similar available

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