Catch fences or rockfall barriers are installed as a measure to contain falling rock. The location and height of fence will be largely dependent on a variety of things. These include the topography of the face and space constraints at the foot of the slope. The fence’s energy absorption capacity will depend on the mass of falling rock, its likely trajectory and required confidence levels.
Catch fences may be designed to act either statically or dynamically. They usually comprise of a combination of high strength netting and wire ropes, supported by either rigid or hinged posts with heights typically in the range 2m to 5m.
CAN uses computer modelling to assess both the rock fall trajectory and energy absorption requirements for catch fences at all locations within a site. CAN has installed numerous catch fences with energy ratings from 20kJ to 3000kJ.
We construct both static and dynamic catch fences. These are often positioned in high or inaccessible locations to capture falling rock before it gathers momentum or is projected into free space. Such work sites are ideally suited to our long reach plant, used in conjunction with rope access and high level rigging. Fences installed include a wide variety of bespoke designs, together with off-the-shelf systems.
Permanent installations have often been located within marine influences, requiring higher levels of protective finish and corrosion resistant metals. CAN also installs a number of different temporary catch fence systems. These enable work to be carried out on cliffs above public access areas or infrastructure.