Oral History Gallery

Extract Text (Duration03.06)

When ships are at sea during the war you can't use mobile phones, they didn't exist then anyway, but you can't use radio you have to maintain radio silence otherwise enemy listening posts will pinpoint where your ships are and take appropriate action. So all the time that ships were at sea, and a lot of the time in harbour, communication relied upon visual signals. Now the majority of it was done by signal lamp. Starting with very small ships, even ships boats carried Aldis lamps. This was a lamp usually run by a battery, only about six inches across, and the beam was, as in any torch, was enhanced by a reflector behind the lamp itself, but in an Aldis lamp operating a trigger deflected the reflection disc at the back so the beam from the lamp was raised or lowered and by means of using the trigger you could send your dots and dashes, Morse code. But in most ships they had 10 inch or 20 inch lamps and they operated on a system with shutters across the front of the lamp, rather like a venetian blind and pressing down on a lever on the right-hand side opened the shutter and if you let the lever go it closed again. So to make a dot you opened the shutter for about a second, and to make a dash you opened the shutter for about three seconds. So that was basically how you sent messages in morse code. The Morse code had it's own alphabet numbers, or a host of different uses and the average signalman I suppose would send about ten words a minute, so you could get quite long messages passed very quickly and passed over quite long distances.