A NEW report has revealed that a 'global response' would have been required to deal with a rogue drill ship smashing into Cumbrae.

A massive rescue operation was mounted by coastguards when the Valaris DS-4 broke free off Hunterston on February 2 last year amid fears was going to run aground or plough into the island.

The full probe into the near-miss has now been released - and reveals just how close the area came to experiencing a massive environmental and ecological disaster.

The report reveals a level of 'tier three' response was mounted, which means that 'global resources would have be necessary to deal with the resulting oil spill due to incident scale, complexity, and/or impact potential'.

Fortunately, the drill ship, which was blown off the jetty at 7.15pm, was halted when its anchor finally held which 'likely prevented the drill ship from going aground on Great Cumbrae', the document adds.

The probe was carried out by the state flag authority of the ship, the Republic of the Marshall Islands.

Marine biologist David Nairn, who runs the Fairlie Coastal group, says the entire Clyde could have been compromised if the near-disaster hadn't been averted.

He added: "The threats were very real and the report brings that home. If it wasn't for the tugs, which provided great support and went above and beyond the call of duty, the unthinkable might well have happened.

"It was a catalogue of failures that led to the incident. The pier wasn't assessed properly, the weather conditions were underestimated and these ships should never have been here in the first place as the harbour wasn't designed for them."

"Hunterston Port is about to host the Petrojarl Foinaven, which services oil rigs at the BP oilfield, about 120 miles west of Shetland. It has bigger tanks and more residual oil in it yet it has no thrusters or engines and a cracked hull. You wonder what lessons have really been learned?"

The reports gives a detailed insight into what happened on board on the night the Valaris DS-4 ship lost its moorings, as its sister ship, the Ensco DS-8 remained moored alongside the jetty with tug assistance and the use of its thrusters.

At 6.45pm, on board the master, chief engineer and crew reported hearing a noise which sounded like the anchor chain as wind speed reached 70 knots - several of the forward mooring lines had parted, and that the drill ship was moving away from the jetty.

The chief engineer went to the engine room to start a diesel generator and to prepare the thrusters.

He made an announcement on the drill ship’s PA system directing all crew members to muster on the bridge, but the diesel generator stopped running a short time afterwards.

A Mayday message was issued at 7.15pm, by which time the DS-4 had drifted approximately halfway across the channel between the jetty and Cumbrae.

At 8.40pm, the first tug arrived. After determining that the DS-4 was not dragging anchor, the pilot directed the tug to go alongside the Ensco DS-8 and help hold that ship alongside the jetty.

At 10.04pm, DS-8’s gangway was pulled off the jetty when the drill ship was struck by a gust of 60-70 knots, with two further tugs arriving to assist.

The ship was eventually re-moored at Hunterston Jetty on February 8 after the crew members were able to start all but one of the azimuth thrusters.

The administrator's report gave a list of conclusions which 'shall in no way create a presumption of blame or apportion liability' and listed factors including the inability of crew members to bring the thrusters online in time to prevent the mooring lines from being broken by the storm force winds.

Additional factors included inadequate consideration of the weather conditions, and poor coordination in the planning process for the ship's arrival locally.

There was also inadequate preparation to ensure that a sufficient number of diesel generators and thrusters would be available in the event of an emergency situation.

Peel Ports say they have carried out a review of their own risk assessment for the lay-up of drill ships with additional mitigation measures now in place.

The incident could bring about widespread change as the report has recommended that the Maritime and Coastguard Agency now consider publishing guidance on the planning and conducting of vessel lay-ups in ports in the United Kingdom.