Discarded steel wire

Lifting KnowHow - CERTEX Danmark A/S

Inspection of steel wire ropes


Steel wire rope will be worn during use and needs to be inspected regularly.
 

Daily visual inspection

At least the intended working section of rope for that day shall be observed with the objective of detecting any deterioration of mechanical damage. This shall include the attachment points of the rope to the crane, that the rope spools correctly and runs smoothly over sheaves.

Any noticeable changes shall be reported, and any damage must be inspected by an expert.
 

Periodic inspection

Steel wire rope shall be inspected at least every 12 months, or more frequently acc. to local legislation by a competent person. Records of such examinations should be maintained.

Steel wire rope on winches and cranes should be inspected regularly acc. to ISO 4309.
Steel wire rope on elevators should be inspected regularly acc. to ISO 4309 and ISO 4344.
Steel wire rope for cableway installations designed to carry persons should be inspected acc. to EN 12927.

Inspection

When inspecting the steel wire, special attention must be paid to the parts of the wire that are empirically exposed to wear and damage.

Wear, broken wires, distortion and corrosion are more common visible signs of deterioration.

Wear is a normal feature of rope service and the correct rope construction ensures that it remains a secondary aspect of deterioration. Correct lubrication of the rope may help to reduce both outer and inner wear.

Broken wires are normally features of wire 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.

Individual broken wires shall be attended to by removing the wire, see figure.

Warning signWARNING! Do not cut the wire, bend it until it breaks close to the inside of the strand. This reduce the risk for ends of wires sticking out of the rope.

Distortions are usually as a result of mechanical damage, and if severe, can considerably affect the wire rope strength.

Corrosion of both outer and inner wires, indicates insuffient lubrication. Pitting on the external wire surface can result in wire breaks. Inner corrosion occurs in some environments when lubrication is inadequate or of unsuitable type. Reduction in wire rope diameter will frequently guide the observer to this condition, but confirmation can only be made by inner examination of the wire rope.

How to remove broken wires

Steel wire rope discards

Steel wire ropes must be discarded according to current standards for the equipment or the manufacturer's recommendations.
Disposal determination must be performed by a competent person with knowledge of applicable norms and standards.

Warning sign  WARNING! Inadequate inspection/disposal can lead to serious injuries.

 

Typical examples of damage and wear on steel wire ropes

1. Mechanical damage due to rope movement over sharp edge projection whilist under load.
Mechanical damage due to rope movement over sharp edge
projection whilst under load.
 
Narrow path of wear resulting in fatigue fractures, caused by working in a grossly oversize groove, or over small support rollers.

Narrow path of wear resulting in fatigue fractures, caused by working
in a grossly oversize groove, or over small support rollers.

5. Severe wear, associated with high tread pressure.

Severe wear, associated with high tread pressure.
Protrusion of fiber main core.

Corrosion of severe degree caused by immersion of rope in chemically treated water

Corrosion of severe degree caused by immersion
of rope in chemically treated water.

Typical wire fractures as a result of bend fatigue.

Typical wire fractures as a result of bend fatigue.

Break up of the steel core resulting from higt stress application.

Break up of the steel core resulting from higt stress application.
Note nicking of wires in outer strands.

Typical exampel of localised wear and deformation created at a previously kinked portion of rope.

Typical exampel of localised wear and deformation created
at a previously kinked portion of rope.

 

Localised wear due to abrasion on supporting structure. Vibration of rope between drum and jib head sheave.
Localised wear due to abrasion on supporting structure.
Vibration of rope between drum and jib head sheave.
 
Two parallel paths of broken wires indicative of bending through an undersize groove in the sheave.

Two parallel paths of broken wires indicative of bending
through an undersize groove in the sheave.

Severe wear in Langs Lay, caused by abrasion at cross-over points on mulit-layer coiling application.

Severe wear in Langs Lay, caused by abrasion at cross-over
points on multi-layer coiling application.

Portrusion of steel core resulting from shock loading.


Portrusion of steel core resulting from shock loading.

Wire fractures at the strand, or core interface, as distict from "crown" fractures, caused by failure of core support.

Wire fractures at the strand, or core interface, as distict from "crown"
fractures, caused by failure of core support.

12. Strand core protrusion as a result of torsional unbalance created by "drop ball" application (i.e. shock loading).

Strand core protrusion as a result of torsional unbalance created
by "drop ball" application (i.e. shock loading).

Multi strand rope "bird caged" due to torsional unbalance. Typical of build up seen at anchorage end of multifall crane application.

Multi strand rope "bird caged" due to torsional unbalance.
Typical of build up seen at anchorage end of multi-fall crane application.


 

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Do you want to know more about steel wire rope?

Then read the article "Technical description steel wire rope" which describes the wire from rod to rope.

See the webinar "Wire rope inspection"

In the webinar, you will get an insight into what to keep an eye on with your steel wire ropes