THE mighty Valaris drill ship was only 15 minutes away from hitting Cumbrae if the anchors hadn't held, the News has learned.

The giant vessel, which broke away from its moorings last Tuesday evening, was halfway between Hunterston terminal and Cumbrae as the second vessel Ensco DS-8 had to be held in position by tugs.

Marine Traffic mapping shows how perilously close the DS4 was from reaching the Cumbrae shore amid 60-70mph winds - and causing a potential environmental disaster.

The incident sparked a major rescue operation involving lifeboats, coastguard helicopter and rescue teams, plus five specialised tugs.

An industry insider told the News: "The DS4 broke its moorings but fortunately the anchor was down. It dragged and then held.

"If the anchor hadn't, or had broke, the vessel was only 15 minutes away from finishing up at Cumbrae shore, and that would have been a major disaster.

"Meanwhile, the ropes were starting to break loose on the other ship, and some tugs from Greenock were sent down to hold it against the jetty - then sat there for 2-3 days holding it in position.

"These ships have a tremendous windage due to the large towers on them, and the ropes were not sufficient to cope with that load.

"While the crew on board had to get the engines started up, it may well have taken them a while as they were not necessarily familiar with everything as they are simply a lay-up crew on the assumption that the boats were secure to the jetty."

"There are lessons to be learned and there will be need to be a very thorough investigation - it should not have broke adrift and only good fortune averted real disaster.

"Usually it is the responsibility of the ship's captain that the boat is tied up properly, but equally the owner of the pier has to be satisfied that everything including the tying up of the ships is in full working order.

"The anchor was re-laid on Monday and everything was put back in position."

Fairlie Community Council wrote to Peel Ports on January 21 over berthing concerns.

Local marine biologist David Nairn, from Fairlie, said: "The pier isn't suitable for this size of vessel.

"We weren't far away from a major ecological incident if it had hit the rocks and broken up. Who knows what diesel, oil and materials could have come out. We got off lightly."

MSP Kenneth Gibson has asked Peel Ports for a full explanation.

Councillor Ian Murdoch added: "I think there has to be an investigation. If it hadn't been for the anchor, I am pretty confident the ship would have hit Cumbrae."

A Peel Ports spokesman said: "As an ongoing multi-agency investigation involving ourselves as the harbour authority, the maritime and coastal agency and others, we are unable to comment on the findings at this time. When the report is concluded and the incident finalised we will be in a position to form a panel of enquiry."

Noah Ship management, who are responsible for the drill ship, DS4, said they had crew of eight on board.

A spokesperson added: "The vessel held position on its anchor some 150 meters off the berth.

"There were no injuries or pollution. The tugs were mobilised as a prudent measure."

Pictures: RNLI/Girvan Lifeboat, Cumbrae Traffic and Travel/Steven Muir. Todd Ferguson, Ian Murdoch.