Care of Mooring Lines

MGN 308 states that “Ropes, wires and stoppers that are to be used in mooring operations should be in good condition. Ropes should be frequently inspected for both external wear and wear between strands. Wires should be regularly treated with suitable lubricants and inspected for deterioration internally and broken strands externally. Splices in both ropes and wires should be inspected regularly to check they are intact.”

Care for synthetic ropes

Synthetic mooring lines must be kept clear of chemicals, chemical vapours and other harmful substance. They should not be stored near paint where they may be exposed to thinning vapours.

Ropes should not be exposed to the sun for longer than is necessary as they may be subject to UV damage.

They should be stored in a well-ventilated place on wood gratings to allow maximum air circulation and drainage.

Lines should be kept away from boilers or heaters and bulkheads which are likely to get hot during operations.

Make sure the fairleads and warping drums are in good condition and free from rust or excess paint. The surfaces of these should be smooth. Jagged surfaces from rust etc will damage the ropes/lines.

If it is necessary to drag ropes on deck make sure they pass clear of sharp edges or rough surfaces

When using winch stored ropes, do not run them through leads that are not on a direct line from the drum as they are liable to chafe on the edge of the spool.

Ensure winch drums are free of chafing surfaces.

Inspection of ropes/lines

Lines should be inspected at regular intervals. These inspections should include checking of the inner strands.

For synthetic ropes the amount of strength loss due to abrasion is related to the amount of broken fibre in the rope’s cross section.

Inspections should include:

  • Looking for glossy/glazed areas
  • Inconsistent diameter
  • Discolouration
  • Inconsistencies in texture/stiffness.

Excessive wear is indicated by powdering and permanent elongation.

Care for wire ropes

  • Avoid leading wires around sharp edges
  • Avoid crossing the wire on the drum, this leads to crushing which seriously reduces the wire’s strength
  • Avoid kinking the wire as this leaves the lay open and the wire permanently weakened
  • Avoid leading wires through excess angles
  • Ropes should be greased/lubricated at regular intervals.
  • Wire ropes will gradually deteriorate throughout their lives and as such should be regularly inspected.
  • Excessive wear, broken wires are usual signs of deterioration
  • Broken wires should be removed as they occur to avoid injury. The number and location of broken wires should be recorder
  • If the nominal wire diameter has decreased by 10% it should be discarded.

Sources

MGN 308