Rigid inflatable boat – unsafe practices

31st December 2015

Rigid inflatable boat - unsafe practices

Initial Report

Report Text:

Three Rigid inflatable boats (RIB’s) were observed off Plas Newydd on the Menai Strait ‘show boating’ with a full load of passengers. Two boats were cutting across each other, the third boat was being used as a filming platform but was also joining in. One RIB turned into a standing wave and ‘hooked’ and two passengers were thrown out of the boat. The passengers were recovered and the three boats returned to the pier at Menai Bridge. A Paramedic attended the scene and one person was taken to hospital with a suspected dislocated shoulder.

As a result of this report, CHIRP made an investigation and established the RIBS do not fall under the MCA’s jurisdiction but that of the local authority that being the Anglesey County Council. They confirmed the incident had been reported and the concerns discussed with the Harbour Master for Caernarvon. Also the Marine Accident Investigation Branch had received notification from the owners, as per Merchant Shipping Act 2012 (Accident Reporting and Investigation). The parent company was most forthcoming about the incident and the remedial work they have put in place. These include replacement RIB’s, with each having improved securing measures on the aft seat and passengers now being issued with automatic inflatable lifejackets, not the manually operated ones provided at the time of the incident.

CHIRP wrote to the film production company and advised that in the future, management should, as a duty of care for their employees, ensure all safety precautions are clearly understood before taking to the water.

CHIRP Comment:

The response by the third party RIB owner was complete: the causal factors were identified and a remedial action plan put in place. Readers are advised to read the MAIB report on ‘RIB Milly’ resulting in 2 fatalities. Also the Norwegian report on the accident with a chartered RIB in Olden, Stryn Norway, where one person died.

MAIB report on the RIB ‘Milly’ can be found at: https://www.gov.uk/maib-reports/ejection-of-6-peoplefrom- rigid-inflatable-boat-milly-in-the-camel-estuary-corn wall-england-resulting-in-3-of-the-people-injured-2- seriously-and-the-loss-of-2-lives

CHIRP wishes to bring attention to a quote in the report of the trials taken to reenact the incident:

During the runs it was noticed that the boat took up a high angle of inward heel when it was turned. It was also noted that when turned tightly at certain speeds the RIB’s heel angle would increase until the aft end of the hull lost grip in the water and slid sideways, leading to a ‘hook’.

The hook rapidly took the boat from its original course as the hull executed a sideways slide across the water, until the boat’s keel gripped and the sideways motion was suddenly stopped, causing the craft to roll violently upright from its banked attitude.

The driver and co-driver reported that they needed to be well prepared for this hooking action by being seated, braced and holding on to handholds, as the forces generated were considerable. The driver suggested after one test turn that an increase in RIB speed of 5 knots would have been sufficient to result in his ejection from the boat, despite being prepared.

CHIRP noted in the short video accompanying the MAIB report, “when the RIB ‘hooked’ it returned 30 degrees to the upright in less than 0.5 second”. Modern RIB’s are getting bigger and faster, with very fast action engine controls. The risk when operating these craft is much greater than in the past and an operator mishandling the craft can result in catastrophic consequences.

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