The Sherman Crab

This device is on display in Worthington Memorial Park at CFB Borden. It's a minesweeping variant of the WW2 Sherman tank that used a shaft-operated (on the right side of the tank above the track) spinning drum with flail chains mounted on a bulldozer-like frame to explode mines. It was one of a series of specialized inventions called the Funnies- created to solve various WW2 battlefield problems.  http://en.wikipedia.org/wiki/Hobart's_Funnies