4* Rockfall barriers certified up to 750kJ This kind of barrier is designed to stop middle sized rocks which develop kinetic energy of up to 750Kj at the point of impact. They are usually sited so as to stop any falling rocks in an area well away from the zone to be protected. It is made of steel supports that can rotate towards the valley and a blocking structure which is made of a 3 strand steel rope net. The structure has a braking system linked to its base which absorbs the energy from the rock gradually via the progressive deformation of the barrier. The barrier has undergone life size crash tests to verify its behavioural characteristics using a block which developed 750Kj at 29m/s. The test certificate was issued by the Faculty of Engineering, Politecnico of Turin.