Nov 202010

imageAn OOW was not familiar with the 360° azimuth propulsion on his vessel had not been informed of, or familiarised with, the full operational status of the system. He did not fully understand the Azimuth / Auto Pilot interface system and alarm and was unable to quickly understand what was happening when he tried to stop the vessel as it approached a barge.

The result was a close call, says Marine Safety Forum in a safety alert.

Although the OOW was an experienced officer he had not used Azimuth propulsion systems before joining this vessel. He first joined the vessel at sea 6 months before the incident; Vessel operations were on-going and no induction or formal introduction to the systems, equipment or procedures was given although he had put great individual effort into familiarising himself with these in so far as he was able.

During the investigation the OOW stated that he was aware that the alarm was linked to the controls because he had inadvertently knocked the controls at some time in the past whilst in Auto Pilot and heard the alarm sound. However, his lack of familiarity with the system was unable to quickly understand what was happening when he tried to stop the vessel and correct company procedures for approaching the barge were not fully understood or followed on this vessel.

TheOOW was approaching from the South West at a speed of around 9 knots in manual control mode with the auto pilot enabled. As he neared the location he reduced speed to around 6 knots and continued the approach.

About this time the Master, who had been off watch, came on to the bridge as they were approaching the barge. When he realised that the OOW was approaching the barge too quickly he ordered him to stop the vessel immediately.

The OOW slowed down the RPM on the main engines and set the controls to direct her thrust astern to arrest the forward movement but this did not seem to be effective. He therefore increased the rpm but this had the effect of increasing the forward speed.

The Master then took over command of the vessel; he used the tunnel thrusters 100% to port to avoid close approach to the barge and took over the controls. At this time he noted that the Auto pilot was enabled, de-selected it and manoeuvred the vessel clear on hand steering.

The vessel passed 100 meters to the NW of the barge passing over her anchor pattern.

Investigation Findings
• The OOW had not disengaged the auto pilot before carrying out the manoeuvre
resulting in the auto pilot continuing to control the direction of the vessel despite the officer of the watch’s attempts to stop her, and in increasing power he just exacerbated the problem.

• There are audible and sensory alarms fitted to the Auto Pilot / Azimuth control interface. When the Auto Pilot is enabled any movement of the controls results in an audible alarm sounding. In addition there is a measure of resistance in the controls, a chattering response from them, and, if not held in position, they will return to the position they were set in when control was passed onto the Auto Pilot. The combination of these responses would normally make it very clear to a navigating officer that the Auto Pilot is engaged if he were aware of these systems.

• The OOW was not focused on the task in hand in that he overshot the approach to the barge unintentionally; there was inadequate attention given to navigation and position monitoring on the bridge and the OOW had not sufficiently allowed for an offset approach.

Investigation Recommendations
• Induction processes were already in place for all crewmembers; these are to be
augmented in the case of Watch Keeping Officers by ensuring that they are given
sufficient familiarisation with the vessels equipment, operating procedures and
arrangements including control systems. This is particularly relevant where officers are
new to the company or there are unusual control systems (I.e. azimuth main propulsion). This is a requirement under STCW (Section A-1/14).

• Procedures for approaching client assets are within the Company SMS and should be
understood and complied with at all times.

• Watch keeping Officers are to remain fully focused on the safe navigation of their
vessels during their periods of duty.

MSF Safety Alert