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Underwater rigging failure

During the recovery of two 400kg buoyancy blocks from the seabed a swaged eye of a strop failed and one of the blocks rose uncontrolled to the surface. No one was hurt and there was no damage.

The eyes of the strop were made up in the usual way; i.e. with an alloy swaged sleeve. It had been under water for about 11 months, during which time the sleeve corroded causing the eye and wire to fail.

The contractor involved has suggested the following precautions should be taken:

  • Do not plan to use alloy swaged rigging which may be left under water for long periods;
  • Use extra caution when recovering subsea loads which may have alloy swaged eyes fitted. Check to find out how long the rigging has been submerged;
      Inspect alloy swaged eyes for pitting and other signs of corrosion before use – discard them if there is any doubt about their condition;

    • Visually inspect rigging each time it is used.

Safety Event

Published: 1 January 1999
Download: IMCA SF 01/99

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