Inventions of War

Monday 22 January: 20.00–21.00
The third of three eye-opening documentaries focuses on the development of the supreme armoured fighting vehicle. The programme joins the 2nd Platoon D Company – part of the famed 1st Cavalry Division of the US Army – as they advance into the field in the Abrams M1A2, the culmination of a century of tank design. As the Abrams is put through its paces, we learn about how the tank evolved into 70 tons of armoured fire power that can kill once every four seconds.

The tank came from unlikely beginnings. In the early 1900s engineer David Roberts was looking for a way to drive a tractor across the muddy fields of eastern England without the wheels sinking in. He came up with the idea of tracks made from chain belts and wooden blocks, which would help the vehicle distribute its weight more evenly. Fighting conditions during the First World War prompted the British Army to investigate the use of such a tracked vehicle to cross trenches and crush barbed wire in warfare conditions. Of course, it would also have to withstand machine-gun fire. The British Mark 4, the tank born of Roberts’ invention, bore no resemblance to today’s tanks, and had many shortcomings, such as tracks that broke due to metal fatigue.

Tank design has had to evolve to keep pace with increasingly ingenious weaponry. In tonight’s programme explosives consultant Dr Sidney Alford carries out an experiment to test the powerful effect of what is known as squash head, a type of explosive ammunition developed in the 1940s to defeat tank armour. The devastating results show why it was thought necessary to increase the thickness of tank armour at the time. But was it possible to employ lighter armour without compromising on protection?

The Russian T-34 held one solution with its sloping armour. No thicker than standard armour, its angle made it more effective at deflecting damaging shells. The T-34 was surpassed by later designs but is widely credited as one of the war’s most effective and influential tanks.

Another of the most feared models of this period was the German Tiger, which had the most powerful gun yet mounted on a tank. But its emphasis on fire power and armour was at the expense of mobility.

Among the most successful modern developments in tank design is that of explosive reactive armour (ERA), which marked a watershed in the battle between weapons and protection. This consists of a sheet of high explosive sandwiched between two steel plates. When a penetrating weapon hits it, the explosive layer detonates, forcing the two metal plates apart and repelling the oncoming missile. Professor Manfred Held, who first recognised the effectiveness of such a system, joins Dr Sidney Alford to put it to the test in a controlled experiment. The results are impressive.

New technologies mean that the future could see active armour systems, which detect and detonate warheads before they even get close to a tank. For designers this is the holy grail, promising the possibility of smaller and lighter vehicles. One thing is for certain: as the battle between fire power and protection gathers pace once more, tank designers will be kept busy to keep this formidable machine of war in the front line.

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