The Great Panjandrum
The British knew that an invasion of northwestern Europe, particularly France, would be essential to win the war. Obviously, this was successful, with the amphibious assault that occurred on D-Day. However, one of the ideas considered by the British was a bit more unusual. The British were concerned with overcoming the Atlantic Wall that was built and reinforced by the Nazis. This wall was 10 feet high and 7 feet thick, built from concrete.
The Panjandrum consisted of two wheels, 10 feet in diameter. These two wheels were connected by an axle packed with two tons of explosives. It was expected that at least a ton of explosives would be needed to produce a tank-size hole in the Atlantic Wall. Rockets attached to the wheels would propel the Panjandrum at high speeds. In theory, the Panjandrum could be sent toward Nazi fortifications at high speed. It would, upon hitting the fortifications, explode.
There was a serious problem with the Panjandrum. Each wheel had nine rockets. During every test run at least one rocket failed to fire or misfired. This caused the Panjandrum to veer radically off course, or even to turn in a circle, returning toward its point of origin. Various attempts were made to correct this, including increasing the number of rockets, adding a third wheel, and adding steel cables. After accepting relatively poor steering, a final trial was scheduled for January 1944. In this final test, the Panjandrum turned full circle, nearly hitting the on-site film crew.
There is some question as to whether the Panjandrum was ever intended to be used; it may have been part of the ruse used to confuse the Germans regarding the planned invasion. There was no attempt made to hide testing of the device, and, in fact, many British citizens played at the seaside during early tests. The Panjandrum wasn’t the only strange, rolling, wheel-like device of the war; at the end of the war, the Soviets captured the German Kugelpanzer, a rolling armored vehicle of sorts.