The Three Families of Rockfall Protection
Rockfall protection splits into three broad families, and confusing them leads to under-designed slopes. Drapery, or simple draped netting, lays mesh over a face so loose blocks slide harmlessly to a catchment at the toe rather than bouncing onto the road below. Dynamic barriers, or fences, are engineered nets on posts and cables designed to catch falling blocks in mid-flight and absorb their kinetic energy. Slope netting, often pinned and tensioned, holds the surface in place to prevent detachment in the first place. Each addresses a different stage of the rockfall process: prevent, restrain or catch. A well-designed scheme may combine all three on a single corridor. At Zhongman we manufacture the mesh and netting components for each family, supplying the steel that protects roads, railways and quarries worldwide.
Drapery and Pinned Systems
Drapery is the simplest and most economical approach for slopes where blocks are small and the toe has room for a catchment ditch. Double-twisted hexagonal wire mesh, the same family used in gabions, is the traditional choice because its non-ravelling weave keeps holding even when individual wires fail. The mesh is anchored along a crest cable and hangs freely, letting debris migrate downward in a controlled way. Pinned, or secured, drapery goes a step further, fixing the mesh tight to the face with a grid of soil nails or rock bolts and bearing plates so material cannot accumulate behind it. High-tensile steel wire mesh and cable net panels handle larger blocks and steeper faces. Zhongman produces double-twist mesh, high-tensile mesh and cable nets to the wire diameters and apertures your geotechnical engineer specifies.
Dynamic Barriers and Energy Ratings
When blocks are large or fall from height, draping is not enough and you need a dynamic barrier engineered to catch them in flight. These systems are rated by the kinetic energy they can absorb, typically from a few hundred up to several thousand kilojoules, and that rating must exceed the calculated energy of the design block. The barrier combines a flexible interception net, often a ring net or cable net backed by wire mesh, with energy-dissipating brake elements, support posts and anchored cables. The brakes are the secret: they pay out under load, stretching the impact over a longer time and slashing peak forces. Specifying a barrier means matching its energy class, height and post spacing to a rockfall trajectory analysis. Zhongman supplies the interception mesh and net components, manufactured from high-tensile galvanized wire to meet the energy class your design demands.
Coatings and Durability on the Slope
Rockfall systems sit on exposed faces for decades, often in wet, freeze-thaw or coastal conditions, so corrosion protection determines real service life. Heavy hot-dip galvanizing is the minimum, but for aggressive environments we strongly recommend Galfan zinc-aluminium coating, which offers markedly better resistance to salt and acidic runoff and is now the default on many highway and rail standards. Where abrasion from debris or chemical exposure is severe, a PVC overcoat adds protection at the cost of some flexibility. Wire diameter, tensile grade and coating weight together set how long a net survives before maintenance. Because these installations are difficult and costly to access for repair, paying for the better coating up front is almost always the economical choice. Zhongman applies certified galvanizing and Galfan coatings and documents the coating mass on every roll.
Specifying and Sourcing Rockfall Mesh
A sound rockfall specification follows the geotechnical analysis: it names the system family, the mesh or net type with wire diameter and aperture, the energy class for barriers, the coating system, and the anchor and cable details. Reference the relevant standards so suppliers cannot substitute lighter material. For international projects, packing and labelling matter; rolls must arrive undamaged and clearly identified to match the design drawings. Zhongman manufactures double-twist mesh, high-tensile mesh, cable nets and ring nets for drapery, pinned and dynamic systems, all with traceable coating and tensile certificates, packed for container export. If you are designing a corridor and need component drawings, samples or a costed bill of materials, send us your slope data and design block parameters and our engineers will respond with a compliant proposal and quotation.