A report from the U.K. Marine Accident Investigation Branch (MAIB) indicates that the use of ultra low sulfur fuel oil (ULSFO) may have contributed to a December 2017 incident in which the U.K. registered RO/RO passenger ferry Pride of Kent struck a jetty and then grounded while departing Calais, France.
The ferry was refloated later that day and subsequently moved to a berth where the passengers disembarked. The ferry’s starboard propeller and tail-shaft were damaged and required repair in dry dock. The jetty was also damaged. There were no injuries to crew or passengers and no pollution.
Safety lessons to be learned from the incident, says MAIB, are:
Control of the ferry during the turn towards the harbor entrance was lost due to the fast rate of turn, strong gale-force winds, use of full rudder and propeller pitch, and the tripping of one of the ferry’s bow thrusters
The omission of a departure briefing to the bridge team contributed to the master not being fully supported, and the helm not being closely monitored
The occasional tripping of bow thrusters and reduced engine speed and shaft speeds were associated with fuel pump issues experienced following a change to ultra-low sulfur fuel oil
Here’s what the full report says on the role of ultra-low sulfur fuel oil in the incident:
2.7 MACHINERY RELIABILITY
Pride of Kent’s No.1 bow thruster tripped during the ferry’s arrival and departure from Calais on 10 December due to the reduced performance of the port main engines’ fuel pumps. The resultant inability of the pumps to supply fuel to the port main engines at the rate required to keep the engines operating close to overload resulted in a reduction of the engines’ speed before the automatic pitch reduction system cut in. As a result, the shaft speed reduced below 145 rpm, the shaft generator tripped, and the No.1 bow thruster stopped.
The occasional tripping of a bow thruster was one of several problems experienced following the change of fuel type from ULSFO from MGO 6 months earlier, although the master was not aware of this connection. Other problems associated with the introduction of ULSFO, which also impacted on Pride of Kent’s maneuverability, included the port engines alarming on overload more frequently, and reduced engine and shaft speeds. At a technical level, these problems were reported by the ferry’s engineers, and P&O Ferries acted quickly to try and resolve them. The fuel pumps were replaced, and technical investigations were undertaken.
However, at the operational level, the continuing issues associated with the fuel pumps’ performance on board Pride of Kent did not unduly impact on the ferry’s schedule, which resulted in the status of the ferry’s main propulsion being assessed on board as “satisfactory” throughout. This assessment did not reflect the increased likelihood of a bow thruster tripping, and reduced main engine and shaft speeds when maneuvering. In view of the potential impact of these deficiencies on the ferry’s maneuverability, a more critical approach was warranted.