Accidents Case of Study Tug

Two die after CMA CGM Simba’s tugboat capsizes

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Container ship CMA CGM Simba (IMO No.907211)

The incident 

The tug Domingue girted and capsized while assisting the container ship CMA CGM Simba departing from the port of Tulear, Madagascar, on September 2016. As a result, two of Domingue’s five crew died. UK MAIB published an investigation report on the accident, providing significant safety issues. 

Domingue had been connected to CMA CGM Simba’s port quarter, to help pull the vessel’s stern off the berth. During the manoeuvre, the prevailing tidal conditions caused CMA CGM Simba to move towards a mooring dolphin. To avoid striking the dolphin, CMA CGM Simba’s master briefly manoeuvred his vessel ahead, the pilot did not warn the tug that they would be coming ahead. As CMA CGM Simba built up ahead speed Domingue girted and capsized.

Safety Issues

  • Domingue was less manoeuvrable than the port’s normal tug which was undergoing maintenance, and its crew were inexperienced in assisting ships
  • The tug was not fitted with a gog rope, nor did the towing point have any mechanism to release the tow in an emergency and doors and hatches on the tug were open
  • The extent to which a plan for CMA CGM Simba’s departure had been discussed between the pilot and Domingue’s skipper before commencement is uncertain, and during the manoeuvre no-one on board CMA CGM Simba monitored the tug’s position
  • Domingue’s skipper was not warned by the pilot before CMA CGM Simba was manoeuvred ahead, and so had no opportunity to re-position the tug

Conclusions

  • Domingue and its crew were able to counter the effects of the wind and tidal stream, but were neither able to counter the effect of CMA CGM Simba’s movements nor prevent the tug from girting, capsizing and foundering.
  • CMA CGM Simba’s master’s and pilot’s intention to apply ahead propulsion was not frst communicated to Domingue’s crew by the pilot, resulting in the ship moving rapidly ahead before the tug could be manoeuvred in an attempt to prevent it from girting.
  • Domingue’s crew were inexperienced in this type of operation. The tug was not ftted with a gog rope and no emergency means were provided to release the two ropes under tension.
  • It is highly probable that Domingue’s open doors and hatches contributed to its rapid capsize due to downfooding.
  • The success of the departure manoeuvre relied on the tug and its crew being capable of meeting changing manoeuvring demands. This required a common, detailed understanding of the plan, proactive communications and an agreed means for monitoring the tug throughout the towing operation.

Recommendations

Towing operations can be dangerous if not managed and executed safely. One particular hazard is girting, which can rapidly lead to a tug capsizing. Girting occurs when high athwarthships towing forces cause a tug to be pulled sideways through the water by the towline. If the tug is unable to manoeuvre out of this position it is likely to capsize. Single screw tugs with a low freeboard, such as Domingue, are at particular risk of girting.

To reduce the dangers associated with girting, especially with small tugs, Shipowners P&I Club recommends the following:

  • The towing gear should minimise the overturning moment due to the lead of the towline, including the position of the tow hook and winch.

  • The towing hook should have a positive, reliable means of quick release able to operate in all conditions.

  • The release mechanism should be designed to be activated locally and from the wheelhouse. All crew members must be familiar with the characteristics of the system and it must be tested frequently.

  • Maintenance of the towing gear must be carried out by competent persons.

  • Openings such as watertight doors and ports must be kept closed during towing operations.

  • Engine rooms should be ftted with high coaming ventilators; air pipes should be ftted with automatic means of closure.

  • Utilisation of a gog rope.

Official report may be downloaded here:

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