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Uncontrolled movement of crane jib during inspection

A member has reported an incidence of uncontrolled movement of a crane jib during inspection operations. The crane boom/knuckle had been lowered to deck to enable access to the main hoist sheave for inspection and maintenance purposes. The crane was powered down and the operator was not in the cab. During the inspection there was an uncontrolled movement of the knuckle section along the deck of approximately 30cm towards the crane pedestal.

The hydraulic cylinders in the main boom were not fully closed when the crane was stowed in this position; therefore the weight of the jib was able to overcome the friction on deck and thus caused the movement of the knuckle head across the deck. At the time of the movement the inspector had been positioned close to the equipment in order to gain access on either side for a complete overview.

Main boom cylinders not fully closed
Main boom cylinders not fully closed
Main boom cylinders fully closed
Main boom cylinders fully closed

A number of key lessons were drawn from this near-miss:

  • Conduct such inspections and ‘routine’ maintenance with the crane stowed in dedicated parking position i.e. crane crutch;
  • Ensure that the main boom cylinders are fully closed to avoid uncontrolled movement of crane jib;
  • Follow approved procedures and always fully brief third party personnel during a toolbox talk prior to commencing the operation;
  • Follow and adhere to the permit to work system, review and risk-assess specific tasks;
  • Ensure that a complete and thorough shift handover is conducted at all times and strive to identify any hazards while the job is in progress; . Barrier off work-site and ensure all personnel are aware of the potential hazards.
Deck area where uncontrolled movement of the knuckle occurred
Deck area where uncontrolled movement of the knuckle occurred
Correct angles and position of crane
Correct angles and position of crane
Correct boom position during the inspection operation
Correct boom position during the inspection operation

Safety Event

Published: 3 December 2008
Download: IMCA SF 17/08

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