Artillery: <b>October 3, 2000</b>

October 3, 2000

Denel, the South African ordnance company, has unveiled its new 105mm Light Experimental Ordnance. The idea is to create a 105mm cannon that can do the job of 155mm guns, but which will take less logistical support since it will be lighter to move and take less ammunition. The Light Experimental Ordnance (LEO) gun is a towed 52-caliber weapon, although an optional rifled pepperpot muzzle brake could extend this to 57-calibers. The LEO gun has a range of 24,000 meters with boat-tail shells and 30,000 meters using base bleed shells. The more expensive base-bleed shells burn a small propellant charge at the rear of the shell during flight. The gas generated from this "base bleed" system fills the vacuum behind the fast-moving shell and extends the range by reducing drag. LEO can also fire armor-piercing fin-stabilized discarding-sabot shells to protect itself from enemy tanks (although the idea of the unprotected crew of an immobile cannon dueling with a moving tank is surely one to inspire tales of posthumous awards for heroism). The current version of LEO weighs about 3,800kg with its split-trail steel gun carriage. The gun together with 100 shells and charges weighs about 6,000kg, compared to 10,000kg (or more) for a 155mm weapon. LEO has towing hooks for transport by truck and lifting hooks for transport by helicopter. The breech is of the swing-and-slide type. The recoil system uses inert gas rather than hydraulic fluid. Traverse and elevation is hydraulic with a manual backup, and provision has been made for an optional automatic aiming system. LEO traverses 40 degrees to either side and can be elevated from -5 degrees to 75 degrees. There is a direct-view optical sight, and a Kentron inertial laying and navigation system. Denel has developed a special round for the LEO gun which has a lethal area of 2,000 square meters, compared to 1,900 square meters of better 155mm shells and the 1,000 square meters of standard 155mm shells. LEO aims to achieve the effectiveness of a larger cannon by increased accuracy and lethality, achieved partly by a proximity fuze to detonate the shell above the target. The ammunition uses a five-zone charge system that is basically a scaled-down version of the 155m charges used by the British Army in the AS90 self-propelled howitzer. Denel now needs to find an export customer willing to fund further developments, particularly in weight reduction. Failing that, it will have to ask the South African Army for continued development funds in the hope of finding export customers later.--Stephen V Cole