One of two late and over-budget ferries has been launched at a shipyard on the River Clyde.

There were cheers from those watching as the MV Glen Rosa was piped into the water at the publicly-owned Ferguson Marine shipyard in Port Glasgow on Tuesday.

The ferry and its sister vessel the Glen Sannox are now some six years late and will cost around three times the original price of £97 million.

MV Glen Rosa, previously known as Hull 802, is a 102-metre dual fuel vessel which will be capable of operating on liquefied natural gas (LNG) and marine gas oil (MGO).

When complete, it will have the capacity to carry up to 852 passengers plus at least 127 cars or 16 heavy goods vehicles, or a combination of both.

It is due to be delivered by September 2025 and will serve Arran on the Ardrossan to Brodick route.

The former head of the shipyard, David Tydeman, was sacked last month over “performance-related issues”, as further delays to the ferries were expected.

The GMB Scotland union said the launch of the Glen Rosa must herald a new era for Ferguson Marine.

No one, apart from the islanders, wanted these ferries finished more than the workforce

Gary Cook, GMB Scotland senior organiser in engineering, said: “The sight of such a ship being launched into the Clyde is a too rare reminder of this river’s proud shipbuilding heritage.

“This yard and these workers can help ensure that heritage is protected for future generations of shipbuilders but only with the support of ministers.

“No one, apart from the islanders, wanted these ferries finished more than the workforce, who have been blameless in this sorry process but been used as a political punchbag for far too long.”

He also called for the contract for seven small ferries for CalMac to be awarded to the yard urgently to give certainty to the workforce and protect the skills at the yard.

Mr Cook said: “The Scottish Government must commit to building the small ferries at Fergusons to create a pipeline of work that will ensure shipbuilding on the Clyde continues for generations to come.”

Beth Atkinson, a qualified welder who completed her apprenticeship at the yard, smashed a special bottling of Ardgowan blended malt whisky off the hull to launch the ferry.

John Petticrew, the shipyard’s interim chief executive, said: “This is a proud day for the shipyard, the people of Inverclyde and every individual who has supported Ferguson Marine reach this landmark moment.

“MV Glen Rosa is the 363rd vessel launched on the Clyde under the Ferguson Marine name. At around 3,000 tonnes, she is considerably heavier than her sister vessel MV Glen Sannox was at launch and sets a new record for the yard in terms of weight at launch.

“Today marks a significant milestone in the delivery of the two new ferries, following the success of MV Glen Sannox’s sea trials in February and last week. This demonstrates the hard work being done by everyone at the yard to complete both ferries as soon as possible.

“MV Glen Rosa will now take her place at the quayside, at the spot Glen Sannox recently vacated, so that her internal fit out can continue.”

Scotland’s Wellbeing Economy Secretary Mairi McAllan attended the launch.

She said: “This is an important milestone for the shipyard and, importantly, provides an opportunity to recognise the workers who have contributed to the building of the MV Glen Rosa.

“It is fitting that it was launched by Beth Atkinson, a highly skilled welder who trained at Ferguson Marine, and who represents the future of Scottish shipbuilding.

“I was pleased to be able to join such an important event for the community, and look forward to seeing Glen Rosa enter service next year and provide vital lifeline services for our island communities.”

Days after the shipyard’s former boss was sacked, the CalMac chief executive officer Robbie Drummond was removed from his post with Duncan Mackison installed as his interim replacement.

Mr Mackison said: “Today’s successful launch is a positive step forward and we are looking forward to welcoming MV Glen Rosa into the CalMac fleet.

“When she enters service, she will provide much-needed resilience and capacity to the Arran community.”

The Scottish Government has been asked for comment.