The rockfall hasard experimental proving ground is located in the Chartreuse massif near Chambéry. The site is hidden at the bottom of an unexploited area of a quarry and is particularly well suited to confidential tests. It is also fully protected. It is one of the most efficient test platforms in Europe. The principle consists of a 25 m long crane boom located at the top of an 80 m high vertical cliff, allowing loads of up to 20 tons to be released. The release hook is equipped with an electrohydraulic "anti-whiplash" system to dissipate the energy released during the release of heavy loads. The maximum impact speed is 133 km/h and the maximum impact energy is 13 500 kJ. An auxiliary jib located on the same cliff serves as an axis for a balancing system allowing to realize horizontal impacts at ground level by transforming the vertical fall of the blocks into circular trajectories tangent to the ground. The dropped loads can impact either devices implanted on the cliff side, typically screens of block nets, or structures on the ground, typically reconstituted and instrumented layers of terrain. The installation is very flexible in its use, because the boom of the crane allows rotations on an angular sector of 90° and translations on a length of 15 m starting from the plumb of the cliff.