What is wire rope?
Wires are the basic building blocks of a wire rope. They lay around a “centre” in a specified pattern in one or more layers to form a strand. The strands lay around a core to form a wire rope. The strands provide all the tensile strength of a fibre core rope and over 90% of the strength of a typical 6-strand wire rope with an independent wire rope core.
Characteristics like fatigue resistance and resistance to abrasion are directly affected by the design of strands. In most strands with two or more layers of wires, inner layers support outer layers in such a manner that all wires may slide and adjust freely when the rope bends.
As a general rule, a rope that has strands made up of a few large wires will be more abrasion resistant and less fatigue resistant than a rope of the same size made up of strands with many smaller wires. The basic strand constructions are illustrated below. In the example, each individual wire is arranged around a central wire to form a 7-wire strand. Six of these strands are formed around a central core to make a wire rope. The rope is specified as 6×7 (6/1) – i.e. six strands each of seven wires.
WIRE ROPE CORE
FIBRE CORE (FC)
Polypropylene or natural fibres are used as the core. Excellent flexibility and lubricant retention.
WIRE STRAND CORE (WSC)
A single strand is used as the core. Simple and cost-effective. Suitable for small diameter rope.
INDEPENDENT WIRE ROPE CORE (IWRC)
A small wire rope is used as the core. Excellent crush and distortion resistance with longer fatigue life and higher breaking strength.
MEASURING WIRE ROPE
Ropes are referred to by diameter size. The correct way to measure a wire rope is across the widest point, ‘The Crown”.
- Wire rope will fail if worn out, shock loaded, overloaded, misused, damaged, improperly maintained or abused
- Always inspect wire rope for wear, damage or abuse before use
- Never use a wire rope which is worn out, damaged, corroded or abused
- Never overload or shock load a wire rope
- Use the correct design factor for the application
- Inform yourself: Read and understand the machinery manufacturers handbook and guidance from the wire rope manufacturer
- Refer to applicable directives, regulations, standards and codes concerning inspection, examination and rope discard criteria
CARE AND MAINTENANCE
WIRE ROPE INSPECTIONS
We help customers implement and manage comprehensive rope inspection programs. The reason for this is simple economics – the relatively low cost of highlighting potential problems before they have a detrimental effect on performance or safety, avoids the relatively high cost associated with downtime or incidents.
We have an in-depth understanding of all aspects of rope management including rope inspections and testing requirements in accordance with Australian and International Standards. We can undertake a thorough inspection of plant and rope systems as part of a complete inspection package to minimise the downtime of your equipment. Ranger can investigate and correct specific issues related to recurrent problems. Our highly trained technicians can efficiently carry out lifting equipment inspections, stringent testing and manage the administration of rope records.