办事指南

Burnt-out case - Tongues of flame melt down the landmine menace

点击量:   时间:2017-11-06 01:01:01

By Andy Coghlan BY TURNING a traditional firework into a blowtorch, defence researchers in Britain have devised a cheap, safe and simple method of burning landmines to a cinder without having to explode them. FireAnt directs a jet of flame at landmines from a few centimetres away, searing a hole in the casing, igniting the detonator before it can set off the mine and incinerating the high explosive so that it simply burns off without exploding. “It’s an uprated Roman candle,” says Paul Reip, head of the team at Britain’s Defence Evaluation Research Agency (DERA), which developed FireAnt. “The difference is that we’ve put a nozzle on the end to direct the flame,” he adds. Like most fireworks, FireAnt is simply a cardboard cylinder containing fuel and a fuse. In the central shaft is around 80 grams of a secret “pyrotechnic” mixture which burns at 1500 °C, about the same temperature as an oxyacetylene blowtorch. At each end of the tube are bungs made of fireclay, the natural ceramic that lines furnaces. One end of the tube has a nozzle, while the other contains an electrically operated fuse which ignites the mixture. Wires from the fuse are connected to a source of electric power, which could be as simple as a car battery. To point the cylinder at a landmine ready for action, it is mounted on a metal bracket shaped like an outsize tent peg. One end is stuck into the ground next to the mine, while the cylinder is put on the other end, pointing downwards at the mine. Alternatively, in the absence of the bracket, the FireAnt can be supported by sandbags. Operated by a battery from a distance of 50 metres, FireAnt torches the mine for around 25 seconds, leaving the explosives to burn themselves out in a few minutes. Because the flame is hot enough to burn a hole through at least 1 millimetre of steel in seconds, it can deal with both metal and plastic landmines. Anti-tank mines, which are bigger, can be destroyed by simultaneously directing three or four FireAnts at them. Afterwards, the spent “firework” is thrown away, as is the husk of the mine. What makes FireAnt so attractive, according to Reip and his team at DERA’s Fort Halstead site in Kent, is that it is cheap to make and simple to use. Reip believes that individual units could sell for as little as $15. The UN puts the cost of clearing one land mine by the traditional method at between $300 and $1000. With some 110 million landmines still uncleared around the world, the potential savings could be massive, says Reip. Cliff Wright and Mick Allen, veteran bomb disposal experts at the Royal Engineers, evaluated FireAnt and were impressed by it. Conventionally, mines are either defused manually—which is dangerous—or blown up with yet more explosives. However, the FireAnt can be operated safely from a distance and it does not leave any explosives that have to be disposed of later. So far, DERA has successfully tested the device on 40 mines. DERA is currently negotiating with a British company to manufacture FireAnt for landmine clearance charities. “We are in discussions to take this to Cambodia, Bosnia and possibly the Falkland Islands,