WW2 Ships Mercer Convoy ZIG ZAG Clock

A WW2 allied convoy ZIG ZAG clock made by Mercer of St Albans.

The clock is working and keeps good time.

ZIG ZAG clocks were used on ships in the Atlantic Convoys with pre agreed timings set on the outer ring with adjustable contacts and when the minute hand made contact a bell or light was activated and the helmsman changed heading to a pre agreed set of courses so that the convoy all moved in the same direction and ZIG Zagged to confuse U-boat Wolf packs.

This 8 day Ships Bulkhead clock has a few telltales that confirm it to be a Zig Zag clock.

The bezel has the Admiralty Pattern AP W 6578 which is specific to ZIG ZAG clocks.

The case has two terminal holes which have been blanked off post war to prevent dust entry. One was attached to the clock mechanism and the minute hand and the other to the insulated outer ring.

The minute hand has a hole where a flexible silver strip was originally soldered to allow it to make a circuit briefly with the outer ring contacts

The dial had four holes in the face where the conductive ring used to be - so we had a new aluminium ring laser cut and mounted through the existing holes on rubber grommets. The adjustable contacts are not present.

We have also turned a black walnut disc with a key slot hangar to allow it to wall hang.

The clock has been overhauled at some recent time and the escapement replaced/ it has just been oiled and it is keeping perfect time.

The dial has some paint flaking but still looks good.

The clock has a 6.5 inch dial and is 5 inches deep. The mount is 9 inches wide.