Guide to Examinations

The continued safe operation of lifting equipment, lifting accessories (e.g. slings) and other systems employing wire rope depends to a large extent on the operation of well programmed periodic rope examinations and the assessment by the competent person of the fitness of the rope for further service.

Examination and discard of ropes by the competent person should be in accordance with the instructions given in the original equipment manufacturer’s handbook. In addition, account should be taken of any local or application specific Regulations.

The competent person should also be familiar, as appropriate, with the latest versions of related International, European or National standards such as ISO 4309 “Cranes - Wire ropes - code of practice for examination and discard”, BS 6570 “The selection, care and maintenance of steel wire ropes”, etc.

Particular attention must be paid to those sections of rope which experience has shown to be liable to deterioration. Excessive wear, broken wires, distortions and corrosion are the more common visible signs of deterioration (see below).

Note: This publication has been prepared as an aid for rope examination and should not be regarded as a substitute for the competent person.

Wear is a normal feature of rope service and the use of the correct rope construction ensures that it remains a secondary aspect of deterioration. LUBRICATION may help to reduce wear (see section on LUBRICATION).

Broken wires are a normal feature of rope service towards the end of the rope’s life, resulting from bending fatigue and wear. The local break up of wires may indicate some mechanical fault in the equipment. Correct lubrication in service will increase fatigue performance.

Distortions are usually as a result of mechanical damage, and if severe, can considerably affect rope strength. Visible rusting indicates a lack of suitable lubrication, resulting in corrosion. Pitting of external wire surfaces becomes evident in some circumstances. Broken wires ultimately result.

Internal corrosion occurs in some environments when lubrication is inadequate or of an unsuitable type. Reduction in rope diameter will frequently guide the observer to this condition. Confirmation can only be made by opening the rope with clamps or the correct use of spike and needle to facilitate internal inspection.

Note: Non-destructive testing (NDT) using electromagnetic means may also be used to detect broken wires and/or loss in metallic area. This method complements the visual examination but does not replace it.

Some of the More Common Types of Wire Fractures Can Include:

A Severed by wear	B Tension	C Fatigue	D Corrosion fatigue

E Plastic wear	F Martensite	G Sheared end

Factors Affecting Rope Performance

Multi-coiling of the rope on the drum can result in severe distortion in the underlying layers.

Bad coiling (due to excessive fleet angles or slack winding) can result in mechanical damage, shown as severe crushing, and may cause shock loading during operation.

Small diameter sheaves can result in permanent set of the rope, and will certainly lead to early wire breaks.

Oversize grooves offer insufficient support to the rope leading to increased localized pressure, flattening of the rope and premature wire fractures. Grooves are deemed to be oversize when the groove diameter exceeds the nominal rope diameter by more than 15%.

Undersize grooves in sheaves will crush and deform the rope, often leading to two clear patterns of wear and associated wire breaks.

Excessive angle of fleet can result in severe wear of the rope due to scrubbing against adjacent laps on the drum. Rope deterioration at the Termination may be exhibited in the form of broken wires. An excessive angle of fleet can also induce rotation causing torsional imbalance.