The Fog Signal Mk.I A - An SOE sabotage weapon

THE Fog Signal serves as a brilliant example to illustrate how an organisation in dire need - like the Special Operations Executive in WW2 - was able to devise a useful and practical solution to an immediate problem without reinventing the wheel.

As the SOE (Special Operations Executive) took root in the occupied countries, the need for efficient sabotage equipment increased. An efficient and fairly easy place for the Resistance groups to attack was the railway system. In Denmark alone 1,525 rails and trains were destroyed during the years 1943 - 1945.

Often it was not only the rails that were blown up. The best and most cost efficient method of sabotage to hamper the German war machine was to derail the train and its cargo of war materials, causing ruin or comprehensive delays.

To this end a triggerdevice was needed for demolishing the rail directly ahead of the oncoming locomotives, eliminating the possibility of bringing the train to a halt before derailment.

The solution was obvious and had been used ever since the late 1800s.

From fog signal device to sabotage weapon

As early as March 1893 an article in a Danish local newspaper reported how a new signal device had been introduced that was able to notify a locomotive driver when, for example, the stop signal was obscured by fog.

The Danish Railway Guide Book of 1944, instructs a railway worker to place three Fog Signals in a row on both tracks in such a way that a locomotive crossing them would produce a series of loud “gunshots” notifying the driver and warning him to reduce speed.

A full version of this feature is published in the July/August issue of Armourer magazine.