Hobart's Funnies were designed after the disastrous raid on Dunkirk. It was realised that vehicles were needed to overcome defences, anti-tank walls and ditches. General Hobart designed many different types of tanks to do this. One of the most reliable was a Sherman tank that could float in the water. They were used by the 79th Armoured division and were a classic example of British ingenious engineering. They were the reason for most of the successes on D day and enabled British and Canadian troops to get inland quickly and complete their objectives.
The Sherman Crab was a standard Sherman but had a flail sticking a few metres out to the front of the tank. The cylinder which the chains are attached to rotated at a very fast speed making the chains thrash the ground. If there were any mines in front of the tank, the chains would detonate the mines and there would be no damage to the tank. These were very useful on D day and if the Americans had not refused to use them on D day, they would not have had so many casualties on Omaha as the Crabs could have detonated the mines and, using the Sherman's main 75mm gun, took out the defences easily.
The Sherman DD tank was a great design. The screen which is shown up on the picture above, was held by a steel ring which went around the tanks body. The tank was again a normal Sherman tank. Two propellers were fitted to the rear of the tank to propel the tank in the water. The idea was that the Sherman DD tank (DD stood for Duplex Drive) would, with its screen up, drive into the sea from a landing craft about half a mile offshore (this is just a guess, I do not know the real distance) and, using the propellers, swim towards the shore. When the tank reached the shore, it would drive up onto the beach, lower its screen and take out the beach defences. The Infantry and other vehicles would arrive afterwards and would have no trouble getting off the beach as there was no German resistance. Sadly, at Omaha beach, only a few of the DD tanks reached the beach as they were launched out of the landing craft too far offshore as the Coxswains of the landing craft feared that if they got too close to the beach, they would hit a mine or be attacked by German Artillery or machine gun fire.
The Churchill was the idea for most of the AVRE's (Armoured Vehicle Royal Engineers) as it was perfect for the designs it was needed for. It had a low, heavily armoured hull that had a spacious interior and had escape hatches at the side for easy escape. Many of the Churchill AVRE's had some sort of bridging device on it. This variant carried a bridge up to a gap, i.e. an Anti-Tank ditch and would drop the bridge over the gap and then drive over the gap, and so would other vehicles. The Churchill AVRE's were fitted with a special, cast turret which had a Petard Mortar which lobbed a large mortar shell about 25-50 metres and would destroy concrete defences i.e. anti tank walls, bunkers or gun emplacements. They were a great success. Many survive in Normandy as memorials.
The armoured Bulldozer was the standard Caterpillar D8 bulldozer that was armoured. It was used in the initial assault for moving mounds of earth or beach defences like Tetrahedra or Hedgehogs which would block the way for other vehicles and Landing Craft coming in when the tide was higher.
