Canadian Pipe Mine

The Canadian pipe mine was a Second World War defensive weapon consisting of a horizontally bored pipe packed with explosive, detonated to blow an anti-tank crater or to wreck a road or runway and deny its use to an advancing enemy. Lieutenant-General Andrew McNaughton conceived the device in 1939 and 1940, adapting diamond-drilling techniques from Canadian mining, and his engineers had proven the method by the middle of 1940; British forces adopted it during the invasion crisis of 1940 and 1941, laying roughly 40,000 feet of explosive-packed pipe under about 90 tonnes of explosive across Britain, with British units trained to install the obstacles themselves by October 1940. Its chief tactical value was concealment, since a buried pipe mine was virtually invisible from the air, unlike a conventional anti-tank barrier, which let defenders leave an apparently open route into a position before detonating the hidden charge beneath an advancing enemy.