A steel wire rope is being used for lifting of loads corresponding the technical data and conditions of use.
The chosen steel wires needs to have the right breaking strength. The wire also needs to be suitable for the intended application. Different cable constructions have very diverged characteristics.
Steel wire ropes can be used by temperatures of -40°C untill +100°C without any form of reduction. Temperatures outside this range needs to be consulted.
Steel wire ropes are consisting of spiral shaped strands round a steel core. The strands are in general designed as a steel wire with strands around a core. The most important characteristics of a cable construction are determined by number, form and dimensions of the separate steel wires as well as the construction of the cable core.
The cable core forms the heart of the cable and states in high extent the cable characteristics. Steel cores with plastic coated cores generally improve the stability of the cable construction.
By choosing the suitable cable core it is possible to avoid damages as a result of high radial forces , for example with multi-layer spooled steel wire ropes.
Steel wire rope strands consist, in general, of one or more thread layers which are spiral shaped round a core. That core can consist of one or more steel wires (=steel core), but also out of fibres (=rope core). The strand structure determine in high extent the technical qualities of the cable structure.
The cable core and the strands are constructed to form the finished wire rope. A distinction is made between one- or multi-layers steel wire ropes. One layer steel wire ropes are usually 6- or 8-strands cable constructions.
Multi-layer steel wire rope constructions are usually rotating resistant or non-rotating constructions, for example 19x7, 35x7.
The construction with multi strand layers makes it possible to manufacture cables which have a very low turning moment on a certain load range because the torque of the different strand layers act against each other.
Be sure to use the correct rope lay direction for the drum. This applies to smooth, as well as to grooved drums.
Many crane models have a two sided grooved drum, one part of it is left, the other right lay grooved. Some wire ropes are more sensitive to this type of design than others; it depends on lifting height, frequency of use, and even the rope diameter as to the type of wire rope most suitable for that application.
In some applications it may be advisable to select the rope lay direction according to the most frequently used drum layers (if more than one layer is spooled).
Here are the conventional type of layers and lay directions:
Small letters are the lay direction of the wire in the strand. Big letters are the lay direction of the strand.
Choice of the right lay direction. Wire rope runs over the upper side of the cable winch.
Wire rope runs over the under side of the cable winch.
Wire ropes must be stored in a need, well ventilated, dry and protected space. Steel wire ropes must be stored by room temperature. By prolonged storage wire ropes must be checked regular on corrosion and if necessary been protected by lubrication. Mark the steel wire ropes to prevent exchange.
Check before use the cable diameter as indicated on the figure below and determine if the end connections are free of visible defects. Check all technical data on the basis of the markings and the corresponding certificates.
Protect the steel wire rope against turn outs before cutting it. Multi lay steel wire rope constructions or parallel stranded wire ropes must at least been tied at two places on both sides of the cutting point.
Avoid damages and twists during unwinding.
We advice to use cable pull stockings with flexible connection to avoid the torsion forces of the old wire rope been transported on to the new steel wire rope. Ensure a safe and secure connection.
By unreeling the steel wire rope from the reel, you must avoid opposite bending. By up wind of the cable drum the wire rope must be sufficiently pre-stressed to guarantee a good winding and safe operation of the cable driving.
Steel wire ropes must be connected exclusively by qualified persons. Check if the steel wire ropes are connected correctly and if they are in good conditions before using them again.
Let new steel wire ropes run in under small partial load.
Due to the fleet angle; wear, torsion and tension may increase. By wrapping the wire rope around a smooth drum the strap hook must be between 0.5° and 2.5° . By a grooved drum the strap hook may lay between 0.5° and 4°.
By using compressed cable construction (langs lay cables), you can avoid damage to the wire rope during reeling.
On cable pulley’s the strap hook may never be more than 2.5°. By twist free or parallel stranded cable constructions the strap hook may not be more than 1.5°.
Make sure that the running steel wire rope cannot slip off the sheave - or flange drum.
By steel wire ropes in use you must check the strap hook on which the wire rope comes into the installation.
The design and the situation of the grooves in cable sheaves or –drums are of the utmost importance for the lifetime of the wire rope. The sheave grooves must support the wire rope over 1/3 of the circumference.
The running steel wire rope must be regularly inspected and greased during use. Steel wire ropes must be visually inspected once a year. Excessive damaged, corroded or worn steel wires may not be used. There should be no kinks, etc. in the steel wire rope. Hands and other body parts must be hold on a distance of the wire rope to prevent injury when the slack wire rope is being pulled tight. The on the wire rope indicated WLL must never be exceeded. You must always wear safety gloves because steel wire ropes can have yarns which can stick out.
Steel wire rope slings and –assembly’s are removable connecting means for lifting and attaching loads corresponding the technical data and conditions of use.
Steel wire rope slings and –assembly’s needs to be visually inspected every year by an expert body and all attached hooks, rings etc. needs to be visually inspected every year and every four years to be tested.
A steel wire rope grommet is a removable connecting means for lifting and attaching loads corresponding the technical data and conditions of use.
A grommet needs to be visual inspected every year by an expert body. Never use a grommet with another rope direction (lay rope left or right ) than the other steel rope , -wire rope sling and/or grommet which already been used by a combination. Never hook the grommet on the red marked part of the grommet. Only use a grommet in a direct line, as a sling or a busked. The on the grommet indicated WLL must never be exceeded.
