As UK MAIB reports in its most recent Safety Digest, a ferry was approaching harbour at 17 knots (kts) with its anchor cleared away ready for emergency use. Suddenly, there was a loud bang and the anchor cable started paying out rapidly.
The crew on the forward mooring deck attempted to apply the anchor brake but it would not hold. The master realised that the anchor was paying
out and applied maximum power astern. The ferry came to a halt just as the anchor cable was stopped by the operation of the deck clench. After a protracted recovery of the anchor and cable the ferry’s deck crew made the anchor secure and, with the permission of the harbour authority, continued their passage into port.
Once the ferry was safely alongside, an examination of the anchor cable brake assembly found that the spring inside it had fractured in several places and rendered the brake inoperable. The company’s technical supervisor was on board at the time and a temporary solution was soon agreed with the classification society and the port authority. The ferry’s crew and passengers were uninjured during the incident and there was no other material damage.
Lessons learned
- Equipment → Corrosion inside the anchor cable brake assembly led to pitting on the spring, which became the initial point of fracture. The routine exposure of equipment to the elements increases its risk of failure and regular checks and maintenance are essential to prevent this.
- Action → The prompt response of the master and crew meant that this situation was safely contained without injury and vessel damage and delays were minimised. Practice drills frequently to be well prepared for when an emergency does occur.
- Communicate → It is fortunate that this accident did not occur minutes earlier, when the ferry’s proximity to a passing ship and the sudden swing induced by the failed anchor cable brake assembly could have had disastrous consequences. The local vessel traffic services (VTS) kept nearby ships well informed of the accident, which enabled passing and overtaking vessels to stay well clear of the ferry.