Feb 182015
 

At about midnight on the evening of 7/8 July 2014 the ro-ro ferry Stena Nautica with 155 passengers onboard suddenly decided it wanted to go hard starboard while departing from Grenaa Port, Denmark. Since she had not cleared the breakwater the result was a contact incident which put holes in her hull below the waterline and much denting. No-one was hurt but to go by the accident investigation by Denmark’s Maritime Accident Investigation Board, DMAIB, it appears to have been another design-assisted accident.

The design of the system led to a situation in which the helm was already turned to a hard starboard position when the switch was made from port bridge wing to hand steering at the centre helm. At that time, the helmsman assumed that the helm was in a neutral, centred position. Thus, when the master ordered port helm, and the helmsman believed he followed the order, he actually just decreased the starboard helm, and the ship kept turning to starboard. When the crew realized what was wrong, it was too late to avoid impact with the breakwater.

Says DMAIB: “The design and operation of Stena Nautica’s steering arrangement was vulnerable to erroneous actions. The arrangement allowed the switch from one control station to another without the watchkeeping crew having full knowledge of the helm and rudder positions. The system did not clearly indicate the helm’s actual position, in this case hard starboard. before switching to centre manual steering. Further, no common procedure was followed when the control was shifted from bridge wings to centre hand steering: Some helmsmen operated the switch button themselves, while others did not.

“On the day of the accident, the helmsman had specifically asked the 2nd officer to operate the switch to ensure that it was done correctly.

“The design of the centre helm was such that its position … was not clearly indicated, especially at night. During the process of changing the steering mode, there was no indication of what action the helmsman took, because the other crewmembers could not visually see what position the helm was in.

“The accident revealed a weakness in the overall design of the bridge layout. The position of the override steering made some officers prefer one system over another, because they wanted to avoid accidentally activating the rudder. In addition, when the bridge officers and ratings were applying different strategies for operating the system, it would at some point lead to confusion caused by a fixation on which mode the system was in. The strategy applied by the bridge crew was to repeatedly confirm that it was switched to helm, while in fact it had already been switched over.

Hand steering wheel. Old wheel, counterweight and fixing hook fitted.

Hand steering wheel. Old wheel, counterweight and fixing hook fitted.

As the ship was refitted with new and additional equipment, there had been little or no analysis of how the operators were actually working on the bridge. Making new equipment available in an operational environment changes the operational process and even though it can optimize the work, it also introduces new risks.”

Following the accident, the company has implemented changes to its bridge procedures to ensure that the steering wheel is centred before takeover. The procedures furthermore prescribe that the officers operate the steering mode selection switches themselves. On Stena Nautica, it has been decided that switch of steering position, from bridge wing to centre, is to be done outside the
breakwaters.

The hand steering wheel which was removed for the refit has been remounted on top of the existing wheel as a preliminary solution (figure 15). With this configuration, it is clearer to the bridge crew whether the wheel is in neutral. Further, a counterweight has been fitted to force the wheel in neutral when not activated by the helmsman. A fixing hook has been installed to keep the wheel centred when not used to avoid confusion.

Download DMAIB Report

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