Falling object – Load dropped by crane

We have received a report of a crane incident that happened in connection with the transport of a riser joint from pipe shuttle to pipe storage deck. In order to transport the riser joint to the pipe storage deck, it was lifted up approximately 1 metre with a gantry crane (pipe handling crane). The crane hook loosened from the hook block fastening point and both the hook and the riser joint fell down again into the pipe shuttle. The 12m long pipe weighed 7.3 tonnes. No persons were in the area during the incident.

The company discerned that the immediate causes of the incident were:

• worn-out threads; and
• ‘play’ in the hook;

with underlying causes including:

• the ‘play’ in the hook had been reported earlier but this had not been followed up;
• check ‘routine’s had been insufficient;
• mounting failure was possible;
• there had been insufficient control; and
• the hook fastening was badly designed.

The following actions were recommended:

• Immediate:
  • Establish relevant check ‘routine’s;
  • Control other similar hooks/lifting arrangements;
  • Contact supplier.
• Further:
  • Soft material inserts to be replaced and a better designed hook to be installed;
  • Total survey of technical condition of crane to be executed;
  • Operating time to be evaluated;
  • Checks to be carried out to ensure that all necessary certificates for lifting equipment are in place and easily accessible.