
A CalMac ferry serving Arran that has been out of action for 20 months for a series of repairs costing more than £12m is to return to service.
MV Caledonian Isles has been sidelined since early last year when annual maintenance revealed extensive corrosion problems.
The ferry, one of the main vessels serving the Arran route, will resume sailing from Ardrossan at 17:00. The return journey from Brodick is scheduled for 18:25.
The ship’s long absence has caused major difficulties for the North Ayrshire port, as the other main ferry which serves the Arran route, MV Glen Sannox, is too big to berth safely at Ardrossan harbour.
The ship’s problems began in January 2024 when annual maintenance inspections revealed serious corrosion that required the removal of the engines to fix.
Work on the 32-year-old ferry – known as “Caley Isles” – was initially expected to last several months at the Cammell Laird shipyard in Merseyside and cost about £5m.
The ship returned to Scotland towards the end of the year but before it could resume service the crew detected metal fragments in a gearbox.
Subsequent investigation revealed the propeller shaft was misaligned and the entire rear of the vessel was twisted. Such problems can develop when a ship is out of the water for an extended period.
The ship then spent most of this year in dry dock in Greenock to rectify the problems but another fault with its propellers was detected before it could return to service.
Engineers believe they have finally fixed that problem, which affected its ability to manoeuvre in harbour, but the total repair bill now exceeds £12m, the equivalent of about a quarter of CalMac’s entire maintenance spend for last year.
Scotland News revealed in July that CalMac is seeking to reclaim some of those costs from Cammell Laird.

The return of MV Caledonian Isles has been welcomed in Ardrossan, which has suffered economic damage from the lack of a regular ferry service.
The new ferry for the Arran route, MV Glen Sannox, is too large to berth safely at the port in windy conditions and has to sail instead from Troon, about 15 miles further south.
The shorter crossing between Ardossan and Brodick means Caledonian Isles will be able to provide five return crossings to Arran each day, compared to three sailings from Troon.
The Scottish government, through its ferries and ports agency CMAL, is currently negotiating with the owner of Ardrossan Harbour, Peel Ports, to buy the site.
This follows years of stalemate over plans to redevelop the port so that the new larger ferries Glen Sannox and Glen Rosa can berth safely.
The Ardrossan Harbour Project was given the go-ahead in 2018 by then-Transport Minister Humza Yousaf, who promised the North Ayrshire town would remain the main gateway to Arran.
However, costs rose and disagreements between the government, North Ayrshire Council and Peel Ports over how much each should pay left the project in limbo.