Hobart's Funnies solve the beach-obstacle problem

The 79th Armoured Division developed specialised vehicles after Dieppe exposed the cost of inadequate armoured support. Sherman Crab flails used rotating chains to clear a lane about 3.3 metres wide at 2.2 kilometres per hour. Churchill AVREs carried a 290 mm Petard mortar for fortifications and could deploy fascines, bobbin trackways or bridges to cross different obstacles. A small box-girder bridge could carry 40 tons across a gap of up to 9.1 metres, while other fittings placed demolition charges before the vehicle reversed clear. Churchill Crocodiles attacked dug-in defenders with flame. The specialist vehicles also needed conventional tank gunfire, which DD swimming tanks were intended to provide alongside the first infantry wave.