World War One
A Heavy RE tank was developed shortly after World War I by Major Giffard LeQuesne Martel RE. This vehicle was a modified Mark V tank. Two support functions for these Engineer Tanks were developed: bridging and mine clearance. The bridging component involved an assault bridge, designed by Major Charles Inglis RE, called the Canal Lock Bridge, which had sufficient length to span a canal lock. Major Martel mated the bridge with the tank and used hydraulic power generated by the tank's engine to manoeuvre the bridge into place. For mine clearance the tanks were equipped with 2 ton rollers.
Between the wars various experimental bridging tanks were used to test a series of methods for bridging obstacles and developed by the Experimental Bridging Establishment (EBE). Captain SG Galpin RE conceived a prototype Light Tank Mk V to test the Scissors Assault Bridge. This concept was realised by Captain SA Stewart RE with significant input from a Mr DM Delany, a scientific civil servant in the employ of the EBE. MB Wild & Co, Birmingham, also developed a bridge that could span gaps of 26 feet using a complex system of steel wire ropes and a travelling jib, where the front section was projected and then attached to the rear section prior to launching the bridge. This system had to be abandoned due to lack of success in getting it to work, however the idea was later used successfully on the Beaver Bridge Laying Tank.
Early World War Two
A Churchill bridgelayer of 51st Royal Tank Regiment in action during a demonstration in the Mezzano area, 30 March 1945.
Once World War Two had begun, the development of armoured vehicles for use by engineers in the field was accelerated under Delaney's direction. The EBE rapidly developed an assault bridge carried on a modified Covenanter tank capable of deploying a 24-ton tracked load capacity bridge (Class 24) that could span gaps of 30 feet. However, it did not see service in the British armed forces, and all vehicles were passed onto Allied forces such as Australia and Czechoslovakia.
A Class 30 design superseded the Class 24 with no real re-design, simply the substitution of the Covenanter tank with a suitably modified Valentine.
As tanks in the war got heavier, a new bridge capable of supporting them was developed. A heavily modified Churchill used a single-piece bridge mounted on a turret-less tank and was able to lay the bridge in 90 seconds; this bridge was able to carry a 60-ton tracked or 40-ton wheeled load.
Late World War 2: Hobart's 'Funnies' and D-Day
Hobart's Funnies were a number of unusually modified tanks operated during the Second World War by the 79th Armoured Division of the British Army or by specialists from the Royal Engineers. They were designed in light of problems that more standard tanks experienced during the amphibious Dieppe Raid, so that the new models would be able to overcome the problems of the planned Invasion of Normandy. These tanks played a major part on the Commonwealth beaches during the landings. They were forerunners of the modern combat engineering vehicle and were named after their commander, Major General Percy Hobart.
Hobart's unusual, specialized tanks, nicknamed "funnies", included:
- AVRE (Assault Vehicle Royal Engineer), used to protect engineers in an assault role, and enable combat engineering.
- ARK (Armoured Ramp Carrier) where the tank itself was the "bridge". Multiple vehicles could be used to span gaps in both the vertical and horizontal. The tank had the turret removed and trackways fitted to the hull. Ramps were attached at each end of the trackways extending the bridging potential and allowing its use in difficult terrain. The tank would need recovery after its use was no longer required.
- Crab: A modified Sherman tank equipped with a mine flail, a rotating cylinder of weighted chains that exploded mines in the path of the tank.
- Armoured Bulldozer: A conventional Caterpillar D7 bulldozer fitted with armour to protect the driver and the engine. Their job was to clear the invasion beaches of obstacles and to make roads accessible by clearing rubble and filling in bomb craters. Conversions were carried out by Caterpillar importer Jack Olding & Company Ltd of Hatfield.
Centaur Bulldozer: A Centaur tank with the turret removed and fitted with a simple winch-operated bulldozer blade. These were produced because of a need for a well-armoured obstacle-clearing vehicle that, unlike a conventional bulldozer, would be fast enough to keep up with tank formations. They were not used on D-Day but were issued to the 79th Armoured Division in Belgium during the latter part of 1944.
In U.S. Forces, Sherman tanks were also fitted with dozer blades, and anti-mine roller devices were developed, enabling engineering operations and providing similar capabilities.
Post war, the value of the combat engineering vehicles had been proven, and armoured multi-role engineering vehicles have been added to the majority of armoured forces.