BSafe Case Study 28 — Twelve of Fourteen Lines Were Already Compromised

Extra Lines, Ahead of a Forecast

With westerly winds forecast to build to Beaufort 7-8, the master had one additional line added forward and aft on top of the standard configuration — four head lines, four stern lines, two spring lines each end — and put the anchor on standby with a tug requested to remain on call. At 0924, with conditions worsening, the master went to the bridge; by 0930, tug assistance was formally requested and two deck officers sent to inspect the lines.

Lines Parting Before the Tugs Arrived

At 0945, before the requested tugs reached the berth, mooring lines began parting one after another as gusts hit Beaufort 10 (50 knots). The head lines went first, then a spring line failed along with the shore bollard cover it was attached to. The ship began drifting toward an adjacent dockyard roughly 120 metres across the waterway. Tugs arrived eight minutes after the last line parted — by which point the ship's bulbous bow had already struck two floating pontoons, then contacted and became trapped against a floating dock and quay in the dockyard.

The master had already ordered the anchor dropped, main engine started, and vehicle ramp raised the moment the lines began parting, activating the emergency alarm and contingency plan and notifying the Port Authority. It took until 1324 — with a pilot, a second pilot, and a fourth tug eventually involved — to get the ship safely re-berthed at a more protected location.

What the Investigation Found

• An independent consultancy's expert assessment of the mooring lines found only one of fourteen deployed lines was in good condition — twelve were inadequate. The lines would likely not have failed had they been in new condition.
• Line failure incidents were not uncommon at this port, with another major event recorded separately — prompting the port authority to acquire berth analysis software to better monitor conditions at berths in use.
• Had a tug arrived before the lines began parting, it could have held the ship alongside — the timing gap between the tug request and the actual failure proved decisive.

Recommended Actions

Grounded directly in the investigation's findings:

1. Mooring line condition needs active, ongoing verification — not just quantity added in response to a forecast — since a compromised line under real load fails regardless of how many others are also deployed.
2. A tug request triggered by a deteriorating forecast should be timed against how quickly conditions can actually change, not against when conditions first start to feel concerning — in this case, the gap between the request and the failure was too narrow to help.
3. A port with a documented pattern of mooring line failures is signalling something about its berth conditions specifically — worth factoring into any vessel's own mooring plan at that location, not treated as isolated bad luck each time.

Human Element Analysis

Test Your Knowledge

Think you've got this covered? Put it to the test in Crew Connect's free Knowledge Checker — try a quick safety round and see how you score.

Related Reading

• BSafe Case Study 20 – another real mooring line incident, a different failure mode, the same underlying equipment risk