Versatile Leca® lightweight aggregate is being used to improve safety at the UK test track of prestige sports car manufacturer Lotus.
In response to upgraded safety requirements from the Health & Safety Executive and its insurers, Lotus Cars has installed new 'gravel traps' using some 600m³ of Leca® in place of traditional heavy aggregates. The lightweight material, which is approved for use at motor circuits by world governing body the FIA, was used for two spin-off areas at the company's facility in Hethel, Norfolk which is also used for race experience training for members of the public. It replaced existing 40mm heavy aggregate, which was proving too dense to stop wayward competition cars effectively. Drivers also faced the added risk of 'rolling' their cars in addition to causing damage to bodywork. Proven in extensive testing in Sweden, Leca® was assessed and found to be a more cost-effective solution than replacing the aggregate with river-washed round gravel, one of few realistic alternatives. Approved contractor Mackinnon Construction Ltd, of Cromer, Norfolk carried out installation of 10-20mm grade material. The existing traditional aggregate was removed, and re-used elsewhere, prior to the installation of drainage within the pit followed by placement of the Leca®. Explains company head, Alistair MacKinnon: "When a car spins off into Leca® it absorbs the energy, bringing the vehicle to a rapid halt without the risk of overturning or substantial damage. "It is an economical solution and is more eco-friendly than the traditional alternatives." He adds: "With the increased popularity of competition car instruction and track days where people can put cars through their paces, insurance has become a major overhead. By improving safety with an innovative material like Leca®, operators can help to keep their costs down." Leca® is a totally natural 'honeycomb-like' material with a hard ceramic outer layer, which is manufactured by heating clay to extreme temperatures. Its use for motorsport circuits, public and private test facilities is becoming increasingly popular after independent testing in Scandinavia proved its performance to be superior to traditional gravel or sand traps. Key benefits of using Leca® include: • Superior stopping power. Tests using a 30cm layer of the material brought a standard saloon car travelling at 56 mph to a stop in just 23 metres. • Light in weight - only 20 per cent the density of gravel or sand. • More cost-effective than the alternative 10-16mm rounded, river-washed gravel. • When crushed, forms non-hazardous, non-slippery powder that does not compromise track safety. • Displays minimal settlement. Easy to handle and remove ruts, etc. • Free-draining and good insulation properties, preventing only the very top layer freezing in cold conditions, therefore ensuring performance is maintained. • Cheaper to transport and more eco-friendly than traditional aggregates.