CHANGE OUT AND RETIRING OF MOORING ROPES

 

CHANGE OUT AND RETIRING OF MOORING ROPES, WIRE ROPES AND MOORING TAILS FROM SERVICE

The Chief Officer is responsible for the maintenance and inspection of the mooring ropes, wire ropes and mooring tails. Since wire lines deteriorate in service, regular inspection is necessary to assess damage to the wire and perform remedial action. Following are some guidelines for inspection:

1. The wire diameter should be checked. A marked decrease is a sign that the line should be removed from service.
2. The outer layers of the wires should be inspected for wear and breaks.
3. Wires should be checked for abrasion. If the outside wires show a considerable loss of metallic area, the line should be removed from service.
4. Individual wires on the strand crowns should be inspected for fatigue breaks.
5. Look for fatigue breaks at or near the valley positions of the strands. If one fatigue break of this type is noted, the line should be removed from service.
6. Remove the wire up to and including the kinked or cut sections.
7. An inspection should be made for corrosion and the line should be retired from service if corrosion has penetrated below the surface of the wires.
8. If the number of broken strands exceeds 10% of the visible strands in any length of wire equal to 8 diameters, the line should be removed from service.
9. The ends of a wire should be periodically reversed in order to evenly distribute the wear.
10. Mooring tails are to be replaced 18 months from the date it was first put into use.
11. Fibre ropes lose strength and deteriorate through normal use and must eventually be replaced. 
12. Weak points and potential areas of failure can be detected and the line repaired or retired before it parts in service.
13. For inspection, the rope should be laid out and the inspector should run the rope between his hands, examining about a foot length at a time. As he proceeds, he should rotate the rope and open the strands or spread the yarns to expose the strand interior surfaces and fibres. 

The following guidelines will aid in determining when a fibre rope should be replaced:

1. Fibre deterioration: The rope should be retired if the fibre is breaking up or if powdered fibre is present.
2. Damage due to external wear: If the strand crowns are worn down considerably, the rope should be retired. If a significant number of outer yarns are also severed, the rope should no longer be used as a mooring line.
3. Local abrasion: Heavy chaffing or fusions of surface fibres are indications of severe abrasion. If these sections are localized, they can be removed and the rope spliced in accordance with the manufacturer’s recommendations.
4. Hockles: Hockling of fibre ropes indicates a severe reduction in rope breaking strength. The hockle should be cut out, if possible, or the rope removed from mooring service.
5. Chemical attack: This may be indicated by staining, or by the ease of filaments or fibres from the yarns can be plucked or rubbed off. If the rope has been chemically damaged, it should be removed from service.
6. Attack by heat: This may be manifested by glazing of the rope surface. In extreme cases, local fused sections on synthetic rope indicate heat through friction and considerable loss of strength can be expected.

Read: Ship Mooring Equipment

Note: Synthetic fibre ropes used for mooring purposes should be made of Polyester/Polypropylene mixture. No synthetic fibre ropes made of other materials are allowed.