BACKGROUND OF SHIP AND VOYAGE DETAILS

The 30,635 gt ro-ro, built in 1991, is registered under the United Kingdom (UK) flag, and has an overall length of 179.7m. This ro-ro was employed as a cross-channel ferry, making several return journeys per day between Dover, UK and Calais, France carrying a mixture of passengers with cars and freight. The ship was powered by four main engines, driving two shafts fitted with controllable pitch propellers. To assist in manoeuvring, two bow thrusters were fitted, and steering was augmented with high lift rudders. As the ship traded exclusively in the North Sea Sulphur Emission Control Area, the fuel used on board was ultra-low sulphur fuel oil (ULSFO), having previously used marine gas oil (MGO) until around six months before the incident. Since the change of fuel type, there had been an increased frequency of problems noted with main engine reliability, including difficulty in starting and clutching in, engines alarming on overload more frequently, and reduced power output.

SUMMARY OF THE INCIDENT

On the day of the incident, the ro-ro ferry was making a routine crossing from Dover to Calais. A storm was causing severe weather conditions in the Dover-Calais Strait, with gale force winds reaching 30-40 knots, creating difficult manoeuvring conditions. Due to the difficult conditions, the first attempt at berthing in Calais was aborted, and the master requested tug assistance prior to undertaking another approach to the berth. Whilst the master was manually controlling the ships heading, bow thruster number one (of two) tripped, however it was made available again within five minutes and it was believed that the thruster tripped due to the excessive demands placed upon it. The ship eventually berthed at 1033 and commenced disembarkation of freight and passengers, before embarking the freight and personnel for the return journey to Dover.

Loading was completed at 1116 and the crew commenced preparations for departure. The delays in berthing meant that the ship was now behind schedule, with the departure originally scheduled for 1035. Despite the difficult conditions, the master determined that tug assistance would not be required for departure. Against company procedures, no formal pre-departure briefing was held with the bridge team to discuss the planned manoeuvre. The master then assumed control of engines, thrusters and steering at the starboard bridge wing control station. At 1138 the master ordered moorings to be let go forward and aft, and all lines were reported clear by 1140. The sequence of the images below provides a clear reconstruction of the course of events. At 1141 the ship was manoeuvred astern and commenced swinging the bow to starboard. At this time the wind speed was recorded at 51 knots coming from the starboard side. At 1142 number 1 bow thruster once more tripped and the main engine indicated a high load alarm. At 1144 the ship’s heading was now almost facing directly into the wind but continuing to rapidly swing to starboard. At this point the master attempted to check the swing by thrusting in the opposite direction and returning both rudders to midships. Also at 1144, the master requested the helmsman to take control of steering from the central control console and maintain heading towards the harbour mouth. However, the helmsman initially did not follow the correct procedure for taking control, meaning that his attempts to steer were ineffective and the rudders remained at midships. This was quickly noted by the master and further instructions were given to enable proper transfer of control. The ship was still swinging to starboard and to counter this, the master ordered full ahead on both main engines and instructed the helmsman to steer south. The helmsman put both rudders hard to port, which resulted in minimal headway and a movement of the stern bodily to starboard due to the nature of the high-lift rudders fitted on this ship. These actions checked the swing to starboard, but did not result in the required swing to port. The ship was now moving closer to a nearby jetty (designation T1), eventually contacting it at 1146, with the starboard propeller subsequently stopping on overload. The ship drifted ahead and grounded around 20 seconds later in the shallow water to the west of the jetty as shown in the final image below.

After suspecting that the ship was aground, the master ordered both main engines to be stopped. The grounding was reported to the local Vessel Traffic Service (VTS), and a check was made to assess damage and any water ingress that may have occurred. Tugs were requested from the VTS, and by 1206 two tugs were made fast and assisted in preventing any further movement of the ship towards the nearby jetty T1.

The master was able to update the crew and passengers on the situation, and noting that no water ingress was detected, was able to avoid the need to evacuate personnel.

By 1430, the ship had refloated on a rising tide and was towed to jetty T1 where it was made fast as a temporary measure. By 1715 the wind speed had reduced to below 40 knots and having made fast additional tugs, the ship was towed to another berth where all passengers and freight were disembarked.

From the time of the grounding until around 1615 the port was closed.

The damage to the starboard propeller and tail shaft were such that the ship had to be taken out of service and be dry docked for repairs. Jetty T1 was also found to be damaged following the incident.

The investigation revealed several factors that resulted in the loss of control of the ship, followed by contact with the jetty and eventual grounding. Principally, a series of misjudgements and errors during manoeuvring in challenging weather conditions resulted in an unrecoverable situation.

It was found that the master may have perceived a time or commercial pressure to depart the berth as soon as possible to prevent the ship falling further behind schedule. This appears to have resulted in the lack of a pre-departure briefing with the bridge team, and the master ruling out the option of awaiting tugs to become available to assist with safe departure.

It is noted that the master’s attempt to steady the ships heading after swinging around for departure was insufficient in the prevailing conditions, and this was likely made worse by the helmsman’s lack of experience with the use of the high-lift rudders fitted on this ship.

The manoeuvre may have been successful, if both bow thrusters remained available, and the main engines were operating optimally. However, it was noted that there had been problems with the reliability of the propulsion and manoeuvring systems since the ship had switched to ULSFO six months prior to the incident.

BSAFE INCIDENT CASE STUDY NO.27 – SUMMARY, BRITANNIA COMMENTARY AND REFLECTIVE LEARNING FORM