A marine impulse transmitter with automatic ‘advance / retard’, 1945

In depth

This clock was designed for the radio room of an ocean-going ship, to advance the hands on a network of subsidiary clocks. It comprises a marine transmitter with half-minute impulse mechanism and jewelled lever escapement. The design is similar to the ‘Pulsynetic’ system Gent pioneered on land, but is governed by a platform escapement with balance (on the left). An ‘advance’ and ‘retard’ mechanism (on the right) allowed the operator to change all the clocks as the ship travelled east to west, or west to east, through time zones. A spare platform escapement is screwed to the back of the case for ease of maintenance at sea. The glazed two-door hardwood case is secured by lock and key, and surmounted with a 9-inch silvered pilot dial with gun metal surround.

By the end of the nineteenth century, developments in steamship technology had reduced the average speed of transatlantic crossing from 18 days to 5. A new era of ocean liners dawned, and with it a new market for reliable marine clock systems. Gent were among the most successful (along with Mercer, Magneta and Synchronome) and boasted that they had supplied clock systems to Cunard, the White Star Line and Royal Mail ships.

Though reliable, this system was never designed for precision timekeeping – that was the job of the navigational chronometer – but rather to keep the ship’s community of travellers synchronised over the course of their voyage. This example is dated in the case to 14 November 1945, which places it around the midpoint of Gent’s marine clock production, which ran from the 1920s until the 1970s.