Lost time injury (LTI) during mooring operations

  • Safety Flash
  • Published on 14 July 2014
  • Generated on 25 April 2025
  • IMCA SF 12/14
  • 3 minute read

A Member has reported an incident in which a crewman (the chief officer) suffered head injuries during mooring of a tug to a Single Buoy Mooring (SBM). 

What happened?

The tug was mooring up to the SBM in order for the dive team to be able to complete ‘routine’ surface maintenance. Once the tug was in position it was realised that the vessel needed to move around 15 metres in order for the divers’ umbilical to reach the SBM. The configuration of the mooring equipment and arrangement being used required the injured person to enter a snap back zone in order to place a stopper on the mooring line, prior to securing it to the bitts.

As he was about to start stoppering off the line, the mooring line slipped off the bitt, striking him on the chest. This pushed him backwards and lifted him up, which resulted in him falling backwards and his head making contact with the deck. He sustained head injuries including a fractured skull. The incident was reported immediately, the vessel returned to port and the injured person was taken to hospital.

Plan view of back deck showing location of injured person

Plan view of back deck showing location of injured person

Mooring lines as in incident (reconstruction)

Mooring lines as in incident (reconstruction)

Swipe to see next image

Our member’s investigation revealed that the causes of the incident included:

  • The mooring arrangement used required the Chief Officer to work in the snap back zone.
  • The mooring arrangement used facilitated a vertical movement upwards (The midship bitts have a slight inboard inclination, the height difference between the mooring roller and midship bitts created an angle and the length of the horizontal extension arm is not long enough to present a sufficient safety guard).
  • There was a deviation from normal operating procedure – inadequate MOC.

Our member took the following lessons to prevent recurrence:

  • Reiterated importance of being able to STOP THE JOB in case of unsafe operations.
  • Took steps to ensure crew were fully informed of risk and control measures.
  • In cases where deviating from an agreed plan of operations, stop the job, re-assess and communicate the additional hazards and control measures via a toolbox meeting.
  • Ensured all personnel involved in the activity or completing simultaneous operations take part in the toolbox meeting.
  • Ensured personnel were trained and have sufficient experience and knowledge to carry out a task.
  • Implement formal MOC process for changes/deviations to normal operating procedures and changes to design of the ship.

Members may wish to use IMCA’s safety promotional poster on mooring safety:

Latest Safety Flashes:

Fatality following a fall from a wind turbine

The Scottish Courts and Tribunals Service, and UK HSE, has published a response to a fatal incident in which a crew member fell to their death.

Read more
UK HSE: Risk of collision with offshore installations from attendant vessels

The UK Health and Safety Executive (HSE) has published Safety Notice ED01-2025 relating to the risk of collision with offshore installations.

Read more
USCG: Hazardous Zone Markings and Safety Protocol Awareness

The United States Coastguard has published Safety Alert 04-25 relating to the importance of Hazardous Zone Markings and Safety Protocol Awareness.

Read more
BSEE: Crane safety awareness during offshore helideck operations

BSEE published Safety Alert 491 relating to a the investigation of a near miss crane incident on an offshore platform.

Read more
Incidents occurring during decommissioning

IMCA has put together a summary of incidents relating to decommissioning.

Read more

IMCA Safety Flashes summarise key safety matters and incidents, allowing lessons to be more easily learnt for the benefit of the entire offshore industry.

The effectiveness of the IMCA Safety Flash system depends on the industry sharing information and so avoiding repeat incidents. Incidents are classified according to IOGP's Life Saving Rules.

All information is anonymised or sanitised, as appropriate, and warnings for graphic content included where possible.

IMCA makes every effort to ensure both the accuracy and reliability of the information shared, but is not be liable for any guidance and/or recommendation and/or statement herein contained.

The information contained in this document does not fulfil or replace any individual's or Member's legal, regulatory or other duties or obligations in respect of their operations. Individuals and Members remain solely responsible for the safe, lawful and proper conduct of their operations.

Share your safety incidents with IMCA online. Sign-up to receive Safety Flashes straight to your email.