94015 Berthing Mooring Boat Sunk

 Near-fatal Mooring Incident
- UK. Daytime. Dull, calm.
- Report No. 94015.

Four men were engaged in mooring a ro-ro vessel, head out on an ebb tide, they were using a motor boat as had been normal practice to put the spring and stern ropes out. The vessel was to moor to a fixed jetty forward, stern ramp onto a floating pontoon, and rest alongside an isolated dolphin amidships, which was also used for a spring from aft.

The vessel, which had twin fixed propellors and bow thrust, was manoeuvring into the berth. At an appropriate time, a boat went to take the after spring. One man was standing on the dolphin ready to throw a heaving line down to take the spring from the boat. As the tide was ebbing, the boat was manoeuvred head to tide close to the vessel beneath the spring lead which was right aft on the port side. The spring was lowered to the boat, it was a stiff rope on a self-tailing (self-tensioning ?) winch. When there was sufficient of the rope in the boat, it was secured by a stopper attached to the gunwale of the boat. The boat came astern while the officer on the after deck signalled to a man on the winch to slack the rope.

The boat slowly got closer to the dolphin and the man on it was just thinking about throwing a heaving line when the ship's rope came taught due to not enough slack being given. One of the boatmen and the man on the dolphin shouted to the officer on the after deck to give more slack. This was passed on to the man on the winch who could not see the boat. The winchman then gave a lot of slack which could not be pulled away instantly, the winch must have been on full speed. The rope, being stiff and heavy did not float, the excess slack went straight down into the ship's propeller. The rope went round the propeller and the next instant the mooring boat was being wound very rapidly in towards the propeller. The boatman who had been holding on to the stopper, obviously let it go, but there was no time to do anything else, it all happened very quickly. The stopper did not release however, as it must have been jammed between the ship's rope and the gunwale of the boat, and it did not break. Anyway, the boat carried on towards the ship's propeller and the boatmen climbed over the high side of the boat and found themselves in the water as it quickly disappeared. They swam as hard as they could, when one of them looked back all he could see was a few bits of floating debris, such as the wooden engine casing and a lifebuoy. All was quiet as the man on the bridge high above had activated the emergency stop on the port engine.

After the incident, the vessel had to go to dry dock due to an excessive stern tube oil leak; the boat was never seen again, despite a berth sweep by the harbour authority.

I am under the impression that the design of the berth was a contributory cause to this accident. In a well desiged berth it should not be necessary for a ro-ro ferry to use mooring boats and I understand that since this accident walkways have been constructed to the spring dolphin and mooring boats are no longer used.

Further to this report, the reporter says that there is one obvious recommendation to make, that is:

The person operating the winch should be able to see with his or her own eyes the destination of the rope which he/she is controlling, not having to watch someone else's hand signals with the obvious delays and misunderstandings that can result. A lot of vessels these days have remote control/wandering leads for the winches. This accident might have been avoided if this system had been fitted to the vessel concerned.