WW1 Original Brass Ships R.N. Convoy Zig Zag Clock

WW1 Convoy or Zig-Zag Clock - Zig-Zag clocks from WW1 are almost impossible to find and even WW2 examples are both scarce and expensive. This has been mounted on a wooden plinth and fitted with an early 20th Century Alarm Bell (not the original) to show how this worked. We had previously thought the maker was the US based company Seth Thomas but with online research we have located an identical example which was identified by the Royal Navy Submarine Museum at Gosport as being manufactured around 1915 by The Standard Time Watch Company of New York, who traded between 1885-1926. This rare early example dates from the first part of the 20th century. In WW1 England was suffering huge losses amongst it's merchant fleet due to German submarine actions. It was therefore decided convoys should not sail a straight course and so avoid providing a easy target for German torpedoes. A means had to be found for large convoys to all alter course at exactly the same moment so as to avoid collisions and these clocks were the tools to do it. Secret sealed orders were issued to all the Captains prior to sailing and these gave the exact time when the helmsman should alter course on a predesignated bearing, in unison with the rest of the fleet, often out of vision and without the need to break radio silence or to use Morse signals. The electrical connector on the hand (replacement) would touch the contact on the brass ring attached to the dial and so complete a circuit which sounded a bell at pre-set times. Every time the bell rang the helmsman would change course. These clock were of basic utility design and made without a bezel or glass exactly as our example. The dial is original, is unnamed and has not been refinished in any way. The metal case has been repainted at some time and has three brass mounting lugs for bulkhead attachment. Three moveable brass contacts remain on the external brass bezel and at the base of the clock are the two screw fitted terminals where the bell or buzzer would have been connected. The minute hand carries the remains of the electrical connector whilst the hour and second hands are of standard design. The clockwork mechanism is key wound and is working happily here in the office although we have no record when it was last serviced and it may be wise for a new owner to have this done seeing the age of this timepiece. As with all our stock feel free to contact us for more detailed pictures and additional information. Whilst we have seen prettier clocks few come with such a story to tell and an extremely rare survivor from a distant war fought on and below the North Atlantic over 100 years ago! Working with key Great original piece. No major damage, a few dints and marks commensurate with age. Named zig zag as ships in a convoy were continually zig-zagging in close formation, leaving little room for intrusion. Besides their artillery, bomb-throwers and depth charges, they also had a well-armed naval escort. Clearly a submarine could not approach closely on the surface, and when she dived her speed was limited. The convoy’s zig-zag pattern was also continually changing, so that it was almost hopeless to judge where the ships would be when she put up her periscope again. They might be heading right away from her, in which case an attack was hopeless. On the bridge was a zig-zag clock. It had a rim around its face and moveable contacts. The clock would be wound up and started when the Commodore ship lowered the flag indicating the start of the zigzag. The ships would all lower their flags and alter course to the first leg. The clock would then be started and when it reached 10 minutes it would sound a buzzer and the 2nd course would be instigated. The zigzag repeated itself each hour until another flag signal would be raised by the Commodore ship indicating a resumption of course and this would be done on the lowering of the flag. As you could imagine, time had to be allowed for the ships to work out the relevant courses and as most would have magnetic compasses it called for some quick maths.

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