Chainlink Specification & Installation
Manufacturing Process: Chain link (Diamond) mesh fencing is manufactured from either plastic coated galvanised wire or uncoated galvanised wire. During the process spirals are interwoven and form a mesh when held under tension. The spirals are joined at the top and bottom of the mesh by either the “clinched” method (Fig. 1) or the “barbed” method (Fig. 2) as specified.
Wire: Pre-galvanised wire is used in the manufacture of chainlink mesh and P.V.C. coated wire. The class of galvanising is determined by the amount of zinc on the wire after galvanising. Two classes of galvanising are available. Class “C”, which is commonly used and Class “A”, if specified.
Plastic Coating: Galvanised wire is plastic coated with a P.V.C. compound which protects the wire against corrosion or any chemical aggressiveness in the atmosphere. The material used is resistant against ultra violet rays. This process drastically prolongs the lifespan of the wire especially in corrosive conditions.
Erection Process: Straining wires are strained between straining posts and secured to the intermediate posts with binding wire. The mesh is tensioned and tied to the straining wire with tie wire at every third mesh along the straining wire. Rolls of mesh can be joined inconspicuously with a spiral to form a continuous line of fencing.
Chainlink Specifications and Installations
- Straining Post
Posts: Prestressed non alkali aggregate reactive concrete post resisting a minimum bending moment of 3800 Nm or alternatively Hot-dipped Galvanised posts of 76mm Ø x 1,6mm (Up to 2,2m High) or 76mm Ø x 2,0mm (2,4m high).
Stays: Prestressed non alkalai aggregate reactive concrete stays resisting a minimum bending moment of 1500 Nm or alternatively Hot-dipped Galvanised stays of 48mm Ø x 1,6mm.
Spacing: Straining posts are spaced at maximum 90 metre intervals.
Steel Alternatives: For the steel straining post as alternative to the concrete straining post, refer to the applicable specification leaflet under the all-steel system (‘S’).
- Intermediate Posts
Posts: Prestressed non alkali aggregate reactive concrete posts resisting a minimum bending moment of 1500Nm. perpendicular to the direction of the fence line.
Spacing: Standards are spaced at maximum 3,5 metre intervals.
- Concrete Bases
Straining Posts: 450 x 450 x 600mm deep.
Stays: 400 x 600 x 400mm deep.
Intermediate Posts: 300 x 300 x 600mm deep.
- Choice of Mesh Cover: Chainlink (Diamond) Mesh or Welded Mesh specification leaflets appear under the materials section in this catalogue.
- Steel Extensions Arms: Extension arms are manufactured from 3mm steel plate and H.D.G. to SABS 763 of 1977 after manufacture the extension arms are securely bolted to the top of the post.
- Gates: Standard Security Gates can be included in the system. Refer to the applicable specification leaflet under Security Gates sections in this catalogue.
- Barbed Tape Concertina: For the B.T.C. applications refer to applicable leaflet under the materials section in this catalogue.
- Barbed Wire: Three strands of Barbed wire are fixed to the extension Arms. For details on quality, type and diameter of Barbed Wire refer to the applicable leaflet under the materials section in this catalogue.
- Toprail (Optional): Galvanised toprail option 38mm x 2mm. Toprail is joined by a nylon spigot every 6,0 metres and is fixed to the top of the post through the steel extension arms.
- Gate Frame: The gate frame and bracing are manufactured from steel tube welded together. For tube size refer to table. Each set of gates are fitted with hinges, drop bolts, sliding bolts and slam plates. The whole gate frame is hot dip galvanised after manufacture.
- Mesh Cover: The gate can be covered with chainlink or welded mesh. For detailed specification refer to the Material leaflet in this catalogue.
- Gate Post: The gate posts are manufactured from steel tube pre-drilled for hinges, stays, saddles and line wires. Steel caps are welded to the post tops. The posts are hot dip galvanised after manufacture.
- Hinges: Eye bolt hinges are fitted to each gate leaf during manufacture. Gate leaves with free-span of more than 2, 5 metres are reinforced with extra tube at hinge positions. The eye bolts are bolted through the steel tube when used with gate posts and welded onto base plates when fitted to a wall.
- Finish: All steel components are hot dip galvanised after manufacture to S.A.B.S. 763 of 1977 specification
DOUBLE LEAF SECURITY GATE
SINGLE LEAF SECURITY GATE
- Repair by cutting away damaged section to form a rectangle in order to insert the new panel and spirals vertically.
- Replace damaged section with similar size from a spare roll of mesh.
- Loosen two spirals equal to the full height of the fence mesh.
- Join with spirals from top down by holding and stretching the panel into position.