Conflict in Masters’ “mental models” was root cause of serious collision

The latest edition of MARS (Mariners’ Alerting & Reporting Scheme) from the Nautical Institute reports on a bow-to-bow collision near the entrance to the buoyed approach channel in Jebel Ali, United Arab Emirates, which MARS’ editors noted was mainly the result of the Masters of two vessels having a different “mental model” of the situation in which they found themselves, while assuming that their counterpart on the other ship had the same mental model.

Container vessel Ever Smart was leaving the port of Jebel Ali in darkness on February 11th 2015 under the control of a pilot. Skies were clear and the sea was calm. The third officer and the Master were also on the bridge, with a helmsman steering by hand. On leaving the container ship, the pilot was scheduled to embark on inbound tanker Alexandra 1 near the entrance to the buoyed port channel.

Meanwhile, inbound Alexandra 1 was approaching the entrance to the port channel and preparing to pick up the pilot. The Master, the OOW and a helmsman, who was steering in hand mode, were on the bridge. The tanker was about 1nm from No 1 buoy, making 126° COG at about 2kt. At this point the port control authority (PCA) entered into an unrelated communication with a tug, instructing it to ‘cross 1nm astern of the tanker’. Crucially, the tanker’s Master heard only part of this radio exchange and mistakenly assumed that port control was talking to the outbound container ship Ever Smart, in relation to his tanker Alexandra 1. The Master of Alexandra 1 assessed that, to pass astern of his vessel, as he now thought it had been instructed by the PCA to do, Ever Smart would alter course to port on clearing the channel.

As the outbound Ever Smart was approaching No 3 buoy the pilot and the Master discussed the pilot’s disembarkation. Alexandra 1 was visible from the container vessel’s bridge and showed on the radar displays, but it was not acquired as an ARPA target. Just before disembarking Ever Smart, the pilot advised the Master to reduce speed to 10kt and to maintain 314° COG. Ever Smart’s Master estimated by eye that Alexandra 1 would pass down his ship’s port side at a distance of 1.5 cables.

As Ever Smart passed between the No. 2 buoys, the pilot launch with the pilot on board cleared the container vessel and headed towards Alexandra 1. Ever Smart’s

Master then increased engine speed to about 11kt as it passed between the No. 1 buoys.

At this point the Master of Alexandra 1 saw Ever Smart and became concerned that the vessel had not altered to port as he had expected. He called VTS port control on the VHF radio to inquire. At this point, the pilot was still on the launch, between container ship and tanker, after having left Ever Smart. Shortly thereafter the two vessels, now both 4 cables from the entrance to the buoyed channel and near the centreline, collided bow to bow.

Ever Smart’s bow was severely distorted and penetrated, while Alexandra 1’s bow and forecastle deck were severely damaged.

The MAIB noted that the collision resulted from several factors. “In particular, a passing arrangement was not agreed or promulgated and the actions of both masters were based on assumptions”, it said.

It also noted that Alexandra 1 was “unnecessarily close” to the channel entrance and that the tanker’s Master “acted on scanty VHF radio information”. Meanwhile, Ever Smart’s bridge team “did not keep a proper lookout or monitor the tanker’s movement”. Because of this inattention they only realized that Alexandra 1 was close ahead seconds before the collision.

The precautions of pilotage and the Jebel Ali port’s vessel traffic service, which would normally co-ordinate and de-conflict the movements of vessels in the port area, were ineffective on this occasion. The pilot’s failure to co-ordinate and communicate the passing arrangements for the two vessels was described by the MAIB as “a significant omission”, since he was the assigned pilot for both ships. Although both Masters were aware of the other vessel, the plan for the meeting of the vessels was ambiguous.

However, all the above flaws were secondary fallbacks that should have prevented an accident that was set in motion simply because the two Masters had different “mental models” of the situation.

MAIB concluded that the collision between Ever Smart and Alexandra 1 stemmed from the vessels’ masters having differing perceptions of how the vessels would pass each other. Because he misheard one PCA transmission, the tanker’s master assumed that the container ship would alter to port on leaving the buoyed channel and pass astern. Consequently, as Ever Smart neared the No1 buoys, he thought it safe to manoeuvre Alexandra 1 slowly ahead across the channel entrance. The container ship’s master, however, assumed that the tanker was stationary and would pass down his port side. Therefore, after the pilot had disembarked, Ever Smart’s Master remained on the same heading and increased speed.

Evergreen Marine (UK) Limited, the managers of Ever Smart, and Iships Management Pte Limited, the managers of Alexandra 1, subsequently took action to improve the standard of bridge watchkeeping on board their vessels.

Alexandra 1 has now been renamed Ambassador and, according to database, is covered by Skuld’s business unit Skuld Oslo 1 through Member International Tanker Management. Registered owner is still Nautical Challenge Ltd.

Ever Smart, according to database, is currently covered by Gard for owner Evergreen Marine (UK) Ltd, with capital provided by Assuranceforenigen Gard gjendidig.

Full MAIB report is here: https://assets.publishing.service.gov.uk/media/5665aff8e5274a0367000010/MAIBInvReport-28_2015.pdf