Some essential "do's and "don'ts"
Never drag ropes over sharp edges, or over surfaces where abrading particles can penetrate between strands and yarns
Avoid Unnecessary chafing at fairleads, over bulwarks, taffrails, etc. All metal parts should be smooth and chaffing points protected by leather, plastic or canvas parcelling, or by worming with small sized ropes. Winch drums must be smooth and free from rust or paint. Fairleads should be in a similar condition and if, of the roller type, should be free running and the bearings well greased.
Avoid contamination by chemicals or fumes as this can damage the ropes. If contamination is suspected, wash man-made fibre ropes in cold running water, e.g. by hosing.
Avoid exposure to all forms of heat. Avoid unnecessary exposure to the degrading influence of strong sunlight.
Avoid build-up of excessive turn in ropes. If this condition has occurred, loops will form, and, if loaded, strand distortion and loss of strength will result. Work excessive twist over end of rope before straining.
Never couple a right-hand laid rope to a left-hand rope no matter what materials are used. If the rope is delivered on a reel, mount the reel on trestles and unreel with the rope coming from underneath the reel.
If the rope is delivered in a coil form, try to keep it off the floor as dirt and damp can damage the rope. Always draw the rope from the middle of the coil bringing it out anti-clockwise.
Regular inspection of ropes is a worthwhile exercise, as the life can be extended considerably by proper repair and protection at obvious chafing points. It must be emphasised that no matter what agency has weakened the rope the effect will be more serious on small sizes than on larger sizes of rope. Consideration should, therefore, be given to the relationship of the surface area of the rope and the rope cross-section.
Examination of about 300mm of rope at a time is recommended, the rope being turned to reveal all sides before continuing. At the same intervals, the strand should be opened as in splicing, but only sufficiently to allow examination of the inside bearing surfaces.
Damage due to external wear
This is the most readily noticeable cause of weakness, particularly if an unused rope is available for comparison. In the extreme the strands become so warn that their outer faces are flattened and the outer yarns severed. Assessment of the degree of wear is by observation of the number of severed yarns, and the thickness relationship of the unsevered yarns at the abraded and unabraded sections. A tensile strength will remove any doubts about the rope's condition.
Damage due to local abrasion
This may be caused by the passage of the rope over sharp edges whilst under tension and such damage can result in serious strength losses, particular if, for example, a deep score is produced in the rope. A deep score extending over ten lays or more of the rope can mean that every out yarn is damaged or cut. These may cause internal, as well as external damage and are not indicated by local rupturing or loosening of the yarns or strands.
Internal wear can be detected by the tell tale signs of a loosening of strands and the presence of powdered fibre. It is most often caused when grit becomes trapped in a rope which is repeatedly flexed in wet conditions.
An overloading rope may be difficult to detect, and a tensile test is invaluable. Check measurements over markers on the rope may reveal local excessive stretch due to overloading, and some hardening of the rope may be observed with a reduction in diameter and considerable reduced extension under load.
This may be revealed by staining or by ease of plucking or rubbing off filaments or fibres from the yarns.
Attack by heat
This may be revealed by glazing of the rope surface. In extreme cases local fused sections indicate heat through friction and a considerable loss of strength can be expected.
If, after careful visual examination, doubts still exist, discard the rope or consult the rope manufacturer.
Maintenance after Inspection
Cut out local damaged sections if warranted, and splice using short butt splice. Do not wait for a damaged section of the rope to part under strain, as the recoil effect can disturb the lay of the rope over a considerable length. Any rope which has broken through overload should be discarded. If thimbles are loose in the eyes, due to rope stretch, firm up by rack seizing. Never allow a thimble to become so loose that it can rock.
Have all splices properly served or taped, and dogs firm seized. Do not allow any tuck to become undone; every tuck is necessary for the optimum splice efficiently in all constructions of rope.
Never dry and fibre rope by use of heat. If possible, store ropes in a cool, dry, well ventilated store or locker, preferably on pallets or festooned, and not exposed to strong light through glass or extremes of heat. Never store on a concrete or dirty floor, and under no circumstances should rope and acid or alkalis be kept in the same area.
Never stand in rope loops or in the path of a rope under strain, and have as few as men as possible in the vicinity of the rope. Always make sure that a rope end is made fast to bitts and not just on the drum end.
Always use man-made fibre ropes for stoppers on man-made fibre rope hawsers. In preference always use stoppers on the double.
Ropes are made to be used, not abused. Abuse of ropes leads to short rope life and possible danger to the user.
Remember to look after your ropes "your life may depend upon them"