Miami Stainless has launched a new 20-metre, 80 tonne testing and wire rope stretching bed, specially designed for pre-installation stretching of wire as well as non-destructive and destructive testing of steel wire ropes, synthetic ropes, chains and shackles.

Wire pre-stretching

Described as the repeated application of a predetermined load to a finished structural wire rope, pre-stretching is generally required when the strand and rope need to be made more elastic by removing the constructional stretch inherent in the wire as it comes from the stranding and closing machines. This is essential for most suspended or guyed structures, since it ensures the stretch parameters used by the designer in predicting the elastic behaviour of the cables after installation.

Pre-stretching is also done to permit measuring and marking at prescribed loads of the strand and rope assemblies.

Wire rope pre-stretching is normally required for large diameter wire ropes, normally 8mm and over, for applications such as suspension bridges, shade structures including carpark shade sails, and structural shade membranes including sports stadium roofing.

Miami Stainless can test cables up to 20 metres in length in one section; however, the unique design allows for testing up to any length as the cable can be tested in sections by passing it through the hydraulic cable grips and testing each subsequent section. The testing and wire rope stretching bed can also test wire ropes up to 32mm in diameter.

Product testing

Miami Stainless will also be using the new test bed for conformance testing of their stainless steel hardware products, wire rope and chain. These stainless steel products are manufactured to meet Australian Standards.

This in-house test bed will now provide a secondary testing facility to ensure that all Miami Stainless products comply with the standards and meet the specifications and break-loads as stated in their product information guides.

Miami Stainless can perform in-house pre-stretching of wires prior to shipment.