CALMAC has been forced to take ferries out of service this winter as it tries to keep its ageing, rusting fleet afloat.

The state-owned operator yesterday announced it would spent £9 million on extra maintenance during the tourist off-season.

Executives said the work - described as a “vessel resilience “ exercise - was on top of routine repairs already planned for the next few months. It is double the spending carried out a year earlier.

Including inter-island services, CalMac runs a total of 49 routes served by 33 vessels each of which is required to undergo a period of annual dry dock maintenance.

The average age of a ship was given as 22 in August 2018 as CalMac awaited two new vessels held up by the ongoing problems at Ferguson Marine.

CalMac’s director of asset management, Julie Philpott said: “Trying to ensure that every vessel gets the proper levels of maintenance and upgrades, while keeping lifeline ferry services running is an extremely complex operation.Not all vessels are suitable for every route and harbour, meaning the matrix we need to design to ensure service continuity is long in the planning.’

‘We try where we can, within the resources available to us, to provide as seamless a service as possible during this period, matching suitable vessels to cover routes. But getting every vessel in for maintenance requires us to do a certain amount of manoeuvring.”