Tweet   During World War 2 the United States Office of Strategic Services and National Defence Research Committee performed a number of tests to determine the most effective way to disrupt ememy railroad services. The 'Mole' was an explosive device designed to automatically detonate when light levels dropped such as when a train entered a tunnel.   This film shows how the Mole was made as well as various tests to determine the most effective location to place the Mole. Needless to say there’s quite a few trains being blown up derailed or otherwise wrecked in this movie! note; not to be confused with a recent similar post showing other methods of derailing locomotives and rebuilding railroads, it's similar but different.