The modern army calls it 'bastion walling', but a 19th-century engineer at the sieges of Sevastopol or Vicksburg would have called it 'gabions' - from the old Italian gabbia, a cage. Then it consisted of wicker baskets, open at both ends, filled with earth, a quickly erected but solid barrier to absorb shot and shell.
The modern version, made in Leeds, has been a British export success. It consists of galvanised steel mesh cages lined with a tough, fibrous material, called geotextile and filled with gravel, earth, sand, concrete, tin cans, even snow. About 38 miles (60km) of the walling is already protecting UN troops in Bosnia, and more is on the way.
Jim Heselden, 45, made redundant in the late 1980s, revived the Italian Renaissance idea. He found quantities of geotextile - similar to felt and made from polyethylene and polypropylene - and steel mesh going cheap, and bought them. He decided to make gabions from the geotextile and mesh to stop sloping land under his business from collapsing. His sisters in the clothing trade offered industrial sewing machines for the idea to take shape.
A family firm has grown up around Mr Heselden's innovation, patented in 1989, of the 'concertainer'. The steel mesh was packed flat, but if one end was anchored, it could be pulled out like a concertina and filled. Hesco can make it to any size and shape, but the standard unit is nine hexagonal segments, forming a 10m (33ft) section.
Mr Heselden first marketed the walling to British Waterways for supporting canal banks. Since then, it has been used for land reclamation in Bermuda and on land he bought on Humberside. Then came the Gulf crisis and the MoD picked up the idea. At first, military engineers had been building fortifications with sand- filled oil drums. The walling was vastly superior, and the MoD ordered 4,000 units - which can cover 64 miles (40km). But the war was over before it was all delivered. The surplus went to Bosnia, after shell tests proved that it would save lives.
A typical Bosnian wall, like that which screens the north side of the British camp in Vitez, consists of two stretches, one on top of the other. It is far stronger and quicker to erect than thousands of sandbags - the 10m stretch is equivalent to about 2,500 sandbags. At fort 'Redoubt' on the mountain road to Vitez, the waling has been artfully combined with logs. At the main British camps at Vitez, Gornji Vakuf and Tomislavgrad, it is used for bombproof walls, and also protects a school and factories.
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