This kind of protection is used to prevent the progressive superficial breaking up of a rock face. The surface to be protected is covered with a net made of steel wire fixed to the ground at its upper and lower edges, and if necessary in the middle, by steel bars. This system is used on slopes where the ground is loose in order to stop the superficial layers weakened by atmospheric action slipping off or to prevent the slope becoming unstable. On rocky slopes it is used to stop small rocks becoming detatched and falling to the valley.If necessary the netting can be coupled with three–strand steel ropes which are usually placed in a rhomboid pattern and increase the restraining capacity of the system.
