When constructing large structures, choosing the correct materials can mean the difference between building success and catastrophic failure. Materials used in construction must be built to last and support thousands—perhaps millions—of tons of peripheral concrete, bricks, steel, etc. Knowing which type of wire roping is needed becomes a critical part of the project manager’s job function. With all of the various steel wiring, ropes, cables and swings available, understanding the physical differences between them is mandatory.
Wires versus Strands
Wires are usually manufactured from non-alloy carbon steel with a carbon content between 0.4 and 0.95%. These wires are formed into ropes and are able to support large tensile forces. Dirt and water penetration are largely reduced, increasing longevity and lowering risk of structural failure.
Cross lay strands have several layers, with the wires crossing each other. The lay length of practically all the wire layers has equal measurements. The wires of any two layers that are superimposed are also parallel. This makes for linear contact. Parallel lay strands are manufactured in a single operation and have a greater endurance than cross lay strands.
Spiral versus Stranded Ropes
Spiral strand ropes are built with independent layers of helically arranged wires and are exclusively made using only round wires. These cables have been used in the engineering and architecture of large structures such as bridges, vessels, stadiums, and glass façade/membrane buildings. Cost-wise, using steel cables has proved more cost effective than using raw materials such as iron or concrete. twaylifting.com/wire-rope-construction-production-process-explained/
Stranded ropes, however, combine several strands of wire laid around a core in one or more layers. The core can be fiber, wire strand or an independent wire rope core (IWRC). Fiber cores are elastic and flexible, however, can be crushed. They do however protect the inner wires from corrosion.
Bent over drums, clusters, and sheaves. They are usually stressed by bending or applying tension.
Stationary Ropes & Stay Ropes
Used for carrying tensile forces, they are loaded by fluctuating and static tensile stresses.
Wire Rope Slings (stranded)
Used to bind together various kinds of goods. They are stressed by tensile forces by bending. Slings are bent over the blunt edges of goods.
Fully Locked Coil Ropes
Fully locked coil wire ropes include exterior “Z” shaped wires that lock together, creating an extremely compact and secure exterior to the rope’s internal makeup. This type of roping helps maintain optimum structural capability in the harshest of environments.
Track Ropes (fully locked)
Used for rails for cabin rollers or loads in cable cranes and aerial ropeways. When used, radius and tensile force increases and stresses decrease.
Structural projects requiring the use of steel wire ropes:
- Bucket Wheel Excavators and Spreaders
- Cable-Stayed Bridges
- Gian Observation Wheels (Ferris)
- Glass & Membrane Roofs
- Glass Façade Systems
- Pedestrian & Cycling Bridges
- Pipeline Bridges & Suspension
- Stadium and Area Roofs
- Stayed Masts & Towers
- Stayed Wind Turbines, Transmission Towers & Offshore Platforms
- Suspension Bridges
- Tied Arch Bridges