Simple Signalling

Go back to basics when in distress

- Paul Donovan

Although most of us who drive 4x4s kit our rigs out with a communication system of some sort, it is still worth knowing how to send a distress signal using more ‘primitive’ means. The most universal way of doing this is to use Morse Code. This code was invented way back in 1836 by Samuel F B Morse with Joseph Henry and Alfred Vail, as a means of transmitting messages over long distances using pulses of electricity. Although Morse code has been superseded by technology, it is still used by some branches of the military, and has its place in a survival situation.

Although Morse code originally used electricity to transmit messages, there are many ways in which in which it can be used. We can use light, in the form of a torch, or a reflector of some sort − a signal mirror, polished tin lid, piece of glass, hand mirror, etc. Sound pulses can also be used, in the form of a whistle or a car horn, or we can visually transmit it by waving a piece of cloth on a stick in an exaggerated manner.

Morse code is transmitted as a series of dots ( . ) and dashes ( – ) . A dot is represented by a short flash or sound, and a dash by a longer flash or sound. So, the international distress signal SOS is represented by three short, three long, three short signals: … --- …

Signal mirror