Scientists are developing super-tanks which would use powerful magnets to melt and destroy incoming missiles and shells.
Each vehicle would be covered in 'smart armour' using electrical fields, instead of thick metal, to give protection against anti-tank weapons. The technology, which is being perfected by defence researchers on both sides of the Atlantic, would transform armoured-vehicle construction.
Current machines, such as Britain's Challenger tank, weigh more than 60 tonnes because they have to carry plating that is more than 2ft thick. Such vehicles require massive amounts of fuel and other supplies, and cause logistical headaches when being transported to conflict zones, say military experts.
But a tank that relied on electromagnetic pulses, instead of plating, to provide a shield against missiles would weigh a modest 20 tonnes. A fleet would form a light but powerful rapid deployment force, and would transform Western nations' ability to take international military action.
Smart-armour research is treated as highly confidential by military officials and manufacturers. A Ministry of Defence spokesman would only confirm that projects aimed at transforming tank construction - part of the Army's Future Land Command project - were taking place. 'Developing technologies that will cut back on armour weight are a key part of that research,' he added.
However, scientists at the US Army Research Laboratory in Aberdeen, Maryland, have now revealed details of how smart armour would work.
According to research published in the current issue of New Scientist, each tank would be covered with tiles made of strong plas tic under which a sandwich of different materials would be installed. First there would be a mat of optical fibres, then a thin sheet of standard armour plating, and underneath that would lie a series of metal coils.
When an anti-tank shell explodes on standard armour, the copper cone of its head is projected as a powerful jet of metal that travels at five miles a second. This jet focuses an immense amount of energy on a tiny area and so can slice easily through several feet of dense metal, causing devastation inside a tank.
However, on striking smart armour a shell would produce a very different reaction. Firstly, it would sever optical cables in the mat below the tank's outer plastic cover. This would trigger sensors to activate electrical capacitors inside the tank which would send a mighty electrical current surging through the metal coils at the base of the smart armour.
A massive electromagnetic field would be created inside the armour, as the high-velocity copper jet begins to pass through it. This field would induce electrical currents in the copper.
'If you get enough current into the copper, you can heat it up and start pinching it in certain regions, making it unstable,' states Mike Zoltowski, of the Army Research Laboratory, in the New Scientist article. The thin copper jet would be flattened and broadened out and so would be unable to cut through the thin standard plating at the base of the smart armour.
Essentially, electromagnets would be used to dissipate the energy of an anti-tank missile or shell, like the force shields that protect the fictional Starship Enterprise.
'This kind of development is now seen as urgent by military planners,' Chris Foss, editor of Jane's Armour and Artillery, said. 'For example, some countries are working on "top attack" missiles which fly over the turret of an oncoming tank instead of striking it front on, where it is most strongly shielded. They would drop their payloads on the tank's relatively unprotected turret area.'
To protect against that, designers would be forced to add even more thick armour plating to these other parts of the tank, adding to its weight and fuel consumption and making it more unwieldy. The answer is magnetic pulses, says Zoltowski. 'The benefit is that you wouldn't need 800 millimetres of steel armour.'