Dropped spanner falls 15 m

Protective netting had been installed for general maintenance on a pipelay system, which would be carried out by crew members and a third-party Rope Access Team.

During work on hydraulic hose replacement, a member of the  third-party Rope Access Team observed two hoses outside the netting protected area and proceeded to replace them.  

A spanner (60 mm x 1.65 kg) was used, secured to the team member by a 1.2m DROPS prevention tooling lanyard, connected by threaded carabiners at both ends. 

During the replacement the carabiner threads became loose allowing the carabiner to open.

The spanner fell 15 metres to the deck area below which was partially barriered off.

No-one was injured. However, workers were nearby on deck.

Investigation findings:

• The third-party Rope Access Team identified additional hydraulic hoses to replace which were outside the area protected by the netting. This additional work was not authorised, and they claimed to be unaware of the received instructions to only work within the perimeter protected by the netting.
  
  
• The third-party Rope Access Team recognised that they may have neglected to secure the carabiner correctly. They reported that the spanner fell from the tower structure and when load was placed on the lanyard recoiled upwards causing the carabiner to disconnect and fall.
  
  
• It was noted that because there is no swivel in the wire lanyard, there was a risk of the carabiner opening if the carabiner thread was open. The carabiner threads were also found to be heavily worn and contaminated which compromised the locking mechanism. The pre-work inspection failed to identify the equipment conditions. The DROPS tool kits were not covered within the planned maintenance system.
  
  
• People were also observed crossing the barriers below the activity. This was not stopped nor reported to the supervisor. In addition, there had been insufficient assessment of the overall DROPS cone to account for the DROPS path or deflection.