In MARS 201841, a small coastal container ship collided with a fishing vessel without noticing. A reader commented that another lesson can be learned from this accident.
The original MARS Report was as follows:
As edited from official Japan Transport Safety Board report MA2017-3
A small coastal container ship was en route at night in good visibility with an OOW and lookout on the bridge. The vessel was on autopilot at a speed of approximately 15.5 kts when the OOW observed another ship ahead on the radar. The target was plotted, showing that it would cross from the starboard side to the port side.
About 2 hours and 25 minutes later the relief OOW came to the bridge. He was given information about the approaching vessel before taking over the watch. At the radar, he extended the true speed vectors, which were set to a three-minute display, and found that the tip of the target’s vector reached a point behind the tip of his vessel’s vector. He therefore assumed that the target vessel would pass astern of his ship.
Meanwhile, as was the practice, the relieved OOW was at the chart table completing the logbook entries with the curtain open and chart table light on. A few minutes later the lookout reported sighting the target vessel.
Danger of Collision
He also asked permission to leave the bridge to attend the head, which was granted. The OOW looked at the target vessel’s true vector on the radar screen. It appeared to him that the direction and length of the vector had not changed. He then glanced out of the window and saw the vessel’s lights at close range to starboard and realised there was a danger of collision. Using the daylight signalling lamp on the starboard side of the bridge, the OOW flashed the vessel about ten times. With no observable response, he then went to the helm and switched to hand steering, setting the rudder hard to port.
No Impact Felt
The OOW did not feel any impact, and assumed that a collision had been avoided. From the bridge wing he was unable to observe the other ship’s lights astern. He then set the autopilot to the previous course and, when the lookout returned to the bridge, asked him if he had felt an impact. The lookout had not. The OOW telephoned the engine room and asked about an impact. The engineer of the watch said he had felt something like being hit by a wave.
No Signs of Collision
Unsure of what to do, the OOW again went out onto the wing and searched astern together with the lookout. Nothing was sighted so, about 30 minutes later, he informed the master. The master decided to investigate further, and went to the bow to see if there were signs of a collision. He did not see any, so was inclined to believe that no collision had occurred.
At the next port, the crew again searched for signs of a collision from the wharf, but did not find any. The vessel left port, but was intercepted by a patrol boat once underway and directed to another port for a detailed inspection.
Fishing Vessel Capsized
The investigation later determined that the target ship was a fishing vessel manned by a sole person, the skipper. He had not returned at the usual time and his family had informed the authorities that he was missing. A search was instigated and the fishing vessel was found capsized and damaged on the port side. The skipper was recovered from inside the vessel and was later declared deceased.
A search was initiated for the other vessel implicated in the collision. After some investigation the small coastal container ship was identified.
Lessons Learned
- If you have the slightest doubt you may have collided with a small boat, stop immediately and investigate fully.
- At night, keep the bridge in ‘blackout mode’. This is important for good night vision. Use red lights for the chart table and shield the light with curtains.
- Use your electronic navigation equipment to its utmost, but also your human power. The eyes of a dedicated lookout and the OOW are fine assets.
- When using the radar for collision avoidance, use relative mode instead of true to give a better visual representation of collision risks.
Reader's Comment
A reader commented that another lesson learned from this accident – reported in the July issue of Seaways – would be to highlight the importance of OOWs fully understanding the strengths and weaknesses of relative and true radar displays. We can only agree with this point.
The reader also remarked that one of the lessons learned, ‘For collision avoidance with a radar, use relative mode instead of true to have a better visual representation of collision risks’, was not included in the findings of the source report. Additionally, the reader maintained, this is not good practice for collision avoidance.
Although it is true that this lesson learned is not a "finding" per se in the source report, MARS staff have more discretion than the accident investigators to direct readers’ attention to what can be improved. The source report is nonetheless concerned with this issue; using relative mode gives an intuitively simple visual representation of collision risk.
This is made abundantly clear by the photos below, which are for the same target at the same moment, with a CPA of 0.76 nm.
MARS Reports
This is one of the December MARS Reports that are part of Report Number 314. A selection of this Report has also been published in SWZ|Maritime’s January issue.
Acknowledgement
Through the kind intermediary of The Nautical Institute we gratefully acknowledge sponsorship provided by:
American Bureau of Shipping, AR Brink & Associates, Britannia P&I Club, Cargill, Class NK, DNV, Gard, IHS Fairplay Safety at Sea International, International Institute of Marine Surveying, Lairdside Maritime Centre, London Offshore Consultants, MOL Tankship Management (Europe) Ltd, Noble Denton, North of England P&I Club, Sail Training International, Shipowners Club, The Marine Society and Sea Cadets, The Swedish Club, UK Hydrographic Office, West of England P&I Club
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