A guard demonstrates the "Penguin" technique. Finding places to dispose of the dirt taken from the tunnels was a constant problem, until the ingenious solution, as shown above, was devised. Bags, sometimes the man's socks, were filled with dirt and secured around the back of the neck by a length of material so that the bags would hang down the trousers at thigh level. A pin attached to a length of string kept the bags closed, but with a tug of the string from inside ones pockets the bags would open and the dirt would fall out of the trousers and on to the floor. The technique was to stroll out into the compound, casually release the dirt, and gently kick it in so that it became indistinguishable from the surface soil. Copyright: IWM HU21220.