Confidential Human Factors
Incident Reporting Programme
The Charity
Aviation
Maritime
M2715
Initial Report
While the vessel was adrift, a tender was prepared for towing from the swimming platform. The line was connected and, following communication between deck and bridge, the operation proceeded on the understanding that the towing line was correctly rigged. As the vessel moved ahead, tension built in the line, which then fouled on the upper section of a bitt, creating a restriction under load.
The officer approached to clear it and, with the line still under tension, attempted to free it by kicking it. When the line suddenly released, it recoiled violently, striking the officer on the arm and neck and briefly rendering them unconscious.
First aid was provided on board, and the casualty was taken ashore for assessment. No serious injuries were found, and they returned to the vessel later the same day.
The operation proceeded on the assumption that the line was correctly set. The fouling under load, combined with attempts to intervene without first removing tension, increased the risk. This highlights the dangers of working on tensioned lines and the need to pause and make the situation safe before taking action.
CHIRP Comment
This report describes a serious incident involving a tensioned line during a towing-related operation between a superyacht and its tender. There is concern over whether the attachment point used, a mooring bitt on the swimming platform, was structurally suitable or approved for towing loads, and how this was verified.
The operation appears to have proceeded on the assumption that the line was correctly rigged, without a final check after the vessel moved ahead. As the load was applied, the line fouled on the bitt, creating an unsafe condition that was not immediately recognised. Limited planning and weak communication between the bridge and deck teams contributed to the escalation.
A key learning point is the attempt to intervene while the line was under tension. Handling or attempting to free a loaded line exposes personnel to snapback risk. In this case, poor judgement of load and timing led to a sudden release and injury. Even small timing errors during such operations can have serious consequences.
Basic risk controls were missing. A short toolbox talk, clearer communication, or pausing engine power could have reduced the risk.
This incident reinforces the fact that all tensioned lines must be treated as high risk. Equipment suitability and rigging should be positively verified before the load is applied, and operations should be stopped to remove tension before any intervention. Strong communication between bridge and deck teams is essential throughout.
This personal injury incident highlights how quickly routine tasks can escalate when stored energy is involved, and the importance of stopping to reassess before acting.
Key Issues relating to this report
Factors related to this report
Complacency – is evident in that the towing line was correctly rigged without a positive verification once the load was applied. The operation appears to have been treated as routine, reducing vigilance at a critical moment.
Situational Awareness – is reflected in the failure to fully recognise the hazard posed by a tensioned and fouled line, particularly the risks associated with stored energy and snapback zones.
Communication – may have contributed, as although there was contact between bridge and deck, there is no indication that a shared mental model of the developing hazard (fouling under load) was established.
Teamwork/Assertiveness – is suggested by the absence of challenge or pause before intervention, with no evidence of cross-checking or escalation before attempting to clear the line.
Capability – (or insufficient application of training) is indicated in the choice to physically intervene on a tensioned line, contrary to widely taught safe line-handling practices.
Key Takeaways
Regulators – Known risks are not the same as managed risks. This case emphasises that well-known hazards such as snapback and stored energy still occur despite extensive guidance, indicating that current safety messages are not consistently influencing operational behaviour. There is an opportunity to better embed, assess, and reinforce guidance such as MGN 520 across the industry, particularly regarding dynamic risk assessment and intervention thresholds.
Managers (Company / Operators) – Procedures only protect people when they shape real behaviour on deck. The incident indicates a gap between procedures and practice, especially in stopping work when conditions deviate from the plan. Managers should consider how effectively crews are trained and empowered to pause operations, how clearly snapback risks are demonstrated, and whether supervision and onboard culture actively reinforce conservative decision-making in routine tasks.
For Seafarers – If it’s under load, don’t touch it, make it safe first. This event is a reminder that tensioned lines are inherently dangerous and can become lethal without warning. Intervening before removing the load, even with simple actions, can lead to serious consequences. Taking a moment to stop, reassess, and make the situation safe is always the safer option, even under perceived pressure to continue.