CALMAC has apologised after being hit with seven ferries out of action this week while one of its sidelined key vessels now out for a month longer than expected.

Caledonian Isles, the 30-year-old ferry which runs on the Arran route, one of the busiest on the Scottish coast, was to be sidelined till at least March 1 following concerns with its main engines.

It has been confirmed it will now be out till March 31, at least. It was due out of its maintenance overhaul a month ago having been gone into dry dock at the start of January.

Services to and from the island of Barra were suspended yesterday as another wave of disruption came as issues have resulted in delays in MV Isle of Lewis's release from its maintenance overhaul. It was due to be complete in February 20.

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CalMac said that it is expected to return to service on Sunday, depending on successful completion of overhaul and sea trials. The issues with the state-owned operator's vessels have hit the islands of Barra, South Uist, Arran, Mull, Islay, Coll, Tiree and Colonsay as managers frantically look to reshuffle the ferry pack.

At the weekend it emerged one of the state-owned ferry operator's oldest vessels which has been serving the Arran route was removed from service completely - leading to the suspension of a vital freight service to Arran.

Users were told that the 38-year-old MV Hebridean Isles, which has been hit with issues since Boxing Day, was removed from the CalMac firing line on Friday with freight services providing vital supplies to Arran from Troon suspended.

An engineer was due to arrive on Monday to assist with vessel and shore technical teams who are investigating but it remains out of service whilst activities continue in identifying and resolving a control issue. No further update is expected until Monday.

The lifeline service to Brodick on Arran has remained a one-vessel service for weeks as MV Hebridean Isles has been unavailable to passengers for weeks and had been concentrating on providing freight services due to bow issues.

The Herald:

MV Isle of Arran has had to serve Arran for weeks on its own because of the issues with Hebridean Isles and Caledonian Isles, cutting the number of available vehicle spaces to about half. It had been expected to remain solo till at least February 16 before being extended to February 28. It will now remain until at least March 31 due to the Caledonian Isles issues.

MV Hebridan Isles had been expected to support services to and from Islay with the MV Isle of Arran for an overhaul for two months from February 5 as part of the rejigging of the network through the state-owned service's programme to improve fleet sustainability through its overhaul programme.

But neither vessel has been able to make it.

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Two vessels have been further hit in the past three days, while other ferries have been sidelined for weeks.

Services to and from Armadale on the Isle of Skye were suspended on Thursday afternoon because of a technical issue with 22-year-old MV Lochnevis.

MV Larven, the 40-passenger catamaran normally operated by Western Isles Cruises, was recruited to operate a foot passenger only charter.

Lochnevis is capable of handling 190 passengers and 14 cars.

Lochnevis has a bow thruster issue and engineers were on board to carry out repairs on Thursday afternoon. CalMac said on Thursday evening that the issue had been fixed.

Further problems which emerged on Tuesday led to 35-year-old MV Isle of Mull being out of action having its movements curtailed. It came back into full service on Thursday afternoon following repairs continue to provide services to and from South Uist.

It emerged that the relief ferry was not permitted to operate in darkness due to a broken gyro. A CalMac message to a user group said the vessel, which is shared between Barra and South Uist was restricted to operating during daylight hours as gyro was operating with a safety case which is limiting its operations until defective components were replaced. CalMac say services had to be amended.

Gyros are a type of non-magnetic compass which are widely used for navigation on ships.

Meanwhile 25-year-old MV Clansman which was delayed from entering service after the ferry operator identified newly steelwork corrosion during its overhaul, remains out of service because of a starboard engine issue.

The Herald: Tha am MV Clansman ga càradh an-dràsta

It is currently holed up on the Clyde undergoing repairs.

CalMac had said on February 10 the impact of Clansman's loss was to have an impact across the network, with Arran, Mull, Islay, Coll, Tiree, Colonsay and Hebrides communities affected due to necessary changes in vessel deployment.

The vessel was due to be back in service on that Friday after moving for its annual maintenance overhaul on January 20.

CalMac then said that Clansman's return had been delayed by "a few days" to cover the emergent steel work.

On Sunday, a further technical issue was reported and investigations were said to be "ongoing".

CalMac has told users that the veteran 34-year-old MV Lord of the Isles would be operating on services to Coll and Tiree till March 12 because of delays to the overhaul programme.

Now CalMac has said that the move will mean that overhaul of MV Hebrides, which was due to start on Feburary 15, will be delayed while Clansman is out of action - and will remain on the North Uist route with a further assessment not expected till Tuesday. CalMac said: "We are sorry for the impact the delays to overhaul, and the additional time required for maintenance is having on the service we provide to our customers and the communities we serve. Our teams are working at pace to complete additional work and resume normal service.

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"Overhaul is an essential part of our maintenance schedule. It's required to maintain statutory certification and to reduce the risk of technical problems emerging in service. This is all just chaos."

A ferry user group official welcomed the apology but added: "How many sorrys have to be said before the Scottish Government and Transport Scotland get their finger out and resolve this."

CalMac have have already cut the Islay service to a single vessel and drafted in MV Finlaggan until February 16. The overhaul issues are due to remain till March 5.

It was supposed to provide services for a month from February 6 to and from North Uist through a temporary timetable brought in by the closure of Uig harbour for essential repairs.

The overhaul to 20-year-old MV Loch Portrain which was supposed to finish early last week and was operating services linking the island of Berneray with Leverburgh on the Isle of Harris was to be out action until March 1, but is now due to return on Sunday.

This all comes during the shutdown of the Skye triangle service due to the new pier construction at Uig. All Tarbert sailings are cancelled under CalMac’s timetable rearrangements. North Uist services are diverted to Ullapool and reduced to a single return run per day until mid-March.

Two new lifeline ferries Glen Sannox and Hull 802 were due online in the first half of 2018 when Ferguson Marine was under the control of tycoon Jim McColl, with one intitially to serve Arran and the other to serve the Skye triangle routes to North Uist and Harris, but they are at least five years late. The last estimates suggested the costs of delivery were quadruple that of the original £97m contract.