State-owned ferry operator CalMac has been plunged into a new "crisis" as five ferries have been sidelined with three breakdowns in a matter of days.

The service to Millport on Great Cumbrae is having to rely on a ferry that is 23 years past its normal working life after one of its usual vessels was crippled.

It comes as it was confirmed that one of the oldest in the fleet MV Hebridean Isles which broke own on Thursday will be retired from action in November.

READ MORE: One of CalMac's oldest ferries to be scrapped in November

CalMac said 39-year-old MV Hebridean Isles if it were to be retained would need a "significant programme of work" that would keep her out of service for months.

(Image: Newsquest)

The 40-year-old MV Isle of Arran is the latest to break down with engine problems on Friday morning on what is one of the Clyde and Hebrides service's busiest routes - to and from Brodick.  After repairs, the ferry operator later on Friday evening said it was back in operation.

The route was supposed to have been served by two new vessels that continue to be held up in the state-owned Ferguson Marine shipyard.

Users that were due to take services from Ardrossan to Arran were bussed to Troon for the alternative £1m-a-month emergency ferry MV Alfred. The ability to board was to be on a first come first served basis.

MV Hebridean Isles was removed from service on Thursday to allow for investigations and repairs to issues with its bow thruster, causing disruption to services to and from Islay.

It has led to services to and from the island of Colonsay during busy summer holiday period also being severely disrupted.

Meanwhile 33-year-old MV Loch Fyne which has been serving Great Cumbrae has also been put out of action after damaging a propulsion unit and ferry users have been told that it is not repairable in the short term.

Seventeen-year-old MV Loch Shira, which has been running services to the island continues to be sidelined and is not expected back till August 7 at the earliest.

CalMac had been forced to remove Loch Shira from one of its busiest routes on April 5 due to it being damaged by heavy vehicles and was originally expected to be sidelined till mid June at the earliest.

The popular tourist island is now having to rely on the 48-year-old elder statesman of the fleet, MV Isle of Cumbrae as the supporting second vessel on Great Cumbrae service, which is one of CalMac busiest. It is working alongside 33-year-old MV Loch Tarbert.

Isle of Cumbrae can take 18 cars - but that is half the number that the normal vessel Loch Shira could accommodate, meaning a drastic cut in capacity.

On Thursday, CalMac warned that vehicles looking to travel to Great Cumbrae face a two-and-a-half hour wait.

The ferry operator said that it was due to the high volume of vehicles trying to cross from Largs.

Meanwhile, MV Caledonian Isles, one of Scotland's oldest and biggest ferries, remains sidelined until at least late August after CalMac was landed with a £5m repair bill over rust.

The ferry operator had warned in February of disruption across the Clyde and Hebrides network as a result of steelwork issues with the 31-year-old MV Caledonian Isles which serves on the Arran route.

It has been out of action since going for an overhaul at the start of January and it had been hoped in the last update that it would be back by July to help with the busy summer period.

READ MORE: 'Heads should roll' over 'pandemic' of ferry fiascos as new delay emerges

The continuing issues with the ageing fleet have meant that the summer only service from Ardrossan to Campbeltown was scrapped for a second year.

The Campbeltown summer service never started last year as it became a casualty of further breakdowns.

A ferry user group official said that there needed to be a wide-ranging inquiry into the uses of ferries that are "outwith their sell-by date".

"We know that there has an inexcusable delay after delay to two ferries due to be delivered by Ferguson Marine, but the knock on effect is that we are relying on vessels that should be scrapped," he said.

"The whole affair is beyond shambolic and quite how we are in the position where a ferry that is 48 years old is being relied upon is shameful.

Campbeltown

"This would not be accepted with public transport in Glasgow or Edinburgh, but appears to be something we islanders have to put up with.

"But this is a crisis, make no mistake about it, that requires not mealy-mouthed words but the ferries that are coming in the future, but how we resolve things in the here and now."

Some 18 of CalMac's 31 working ferries that were in service in 2021 and deployed across Scotland are now over 25 years old.

MV Isle of Arran which usually serves as the second Arran ferry in the summer, is second only to Isle of Cumbrae in a list of CalMac's oldest ferries. It has been the regular summer ferry on Argyll and Bute's Tarbert to Portavadie route when it is not rerouted.

The others that are over 25 years old are Hebridean Isles (39) Loch Linnhe (38), Loch Riddon (38) Loch Striven (33), Loch Ranza (37), Isle of Mull (36), Lord of the Isles (35), Loch Dunvegan (33), Loch Fyne (33) Loch Buie (32), Loch Tarbert (32) Caledonian Isles (31), Isle of Lewis (29) and Loch Bhrusda, which was completed in May 1996.

After 1973, when the Caledonian Steam Packet Co. acquired most of the ferries and routes and began joint Clyde and West Highland operations under the new name of Caledonian MacBrayne, the official expected life of a ferry had been 20 years.

That is until 2002, three years after the 1999 devolution when the then Scottish Government-owned Caledonian MacBrayne which then controlled the fleet and procured vessels, extended the 'working life' from 20 years to 25 years.

Scottish Government-owned ferry owners and procurers Caledonian Maritime Assets Ltd which took control of the ownership of the ferry network and the purchase of new vessels in 2006, has since moved the 'expected useful life' from up to a maximum of 25 years to 35 years.

New ferries Glen Sannox and sister ship Glen Rosa being built at state-owned Ferguson Marine in Inverclyde, which were due online in the first half of 2018, with both now due to serve Arran, are at least six years late, with costs expected to be quadruple the original £97m contract.

CalMac and Transport Scotland were approached for comment.