All-rubber tracks save weight, fuel

London - UK defence supplier BAE Systems showed all-rubber tracks for military vehicles at its stand at the recent DSEi show in the UK.

The tracks are made by Soucy International based in Ontario, Canada. Jack Jennings vice-president for business development at Soucy said the tracks are made in a similar way to tyres, using a reinforced band, together with different compounds for different elements of the track.All the lugs and textures are moulded into the track as it is cured; not bonded later to a plain belt. This gives much better reliability and longer life.

The tracks are currently being used to support vehicles up to 28 tonnes

in weight and are being developed for vehicles up to 35 tonnes.

Where conventional tracks are made up of large blocks of steel connected by a loose web, the new rubber tracks are designed to have a more or less constant cross section, with a tread pattern designed to give good grip when climbing a slope.This gives two advantages. First is that the ride is much more comfortable, meaning crews become less fatigued and also that the noise of the tank is less, permitting  a more stealthy approach

In addition, however, the drive wheels engage more positively with the rubber drive lugs, meaning the drive train is far more efficient, so the system uses a great deal less fuel than the steel equivalent.

Another benefit is more consistent track length. The tracks are built like a cross between a continuous conveyor belt and a tyre, with a jointless band made of a reinforcing material such as aramid, steel or polyester. Jennings said the reinforcing material depends on the specific application. This reinforcement constrains the length of the belt, meaning the track remains the same length over time. In comparison the older steel systems would suffer from wear, meaning crews had to remove a track element every few weeks, in order to overcome the effects of stretch and wear.

Jennings said the track can carry a vehicle on a 30-tonne vehicle on two tracks each of which is 16 to 20 inches wide. The main enemy in this application, he said is heat, as the track can be heavily loaded and is moving at speed. Soucy uses its own internal compounding expertise and mixers to create compounds which deliver grip at the tread; strength at the drive lugs and low rolling resistance in the areas which flex most.

Jennings said Soucy designs the rubber compounds for each application. In previous designs, suppliers have made rubber shoes to go over each steel track element, in order to protect highways. When a tank or tracked vehicle drives along a road, the steel track elements quickly damage the road surface, so the vehicles use rubber shoes, but these are not designed for lifetime or performance. Soucy, said Jennings has applied specialist knowedge to make rubber tracks which out-perform the existing steel designs in almost every aspect.