One of Scotland’s newest ferries leaked flammable gas during a crossing while carrying more than 80 passengers last year.
The Glen Sannox entered service in January last year, but on June 3, 700kg of methane was vented from the ferry over the course of 12 minutes during a crossing between the Isle of Arran and the mainland with 82 passengers onboard, according to the BBC.
The ferry is the first of its kind built in the UK to run on liquified natural gas (LNG).
According to the broadcaster – which obtained details of the incident through a freedom of information request – gas alarms sounded and the port main engine automatically shut down as it made its way to Brodick on the west coast island.
Lessons were learned following the incident in June 2025, and remedial actions taken
It completed the crossing using diesel fuel, but on the following return sailing to Troon, South Ayrshire, the gas was vented.
It was described as a “critical failure” by ferry operator CalMac, but it was not disclosed publicly until the BBC report on Wednesday.
The investigation found the crew should not have continued to use gas on the return journey until the cause of the alarm activation had been found.
A spokeswoman for CalMac said: “MV Glen Sannox has proven to be a valuable member of the major vessel fleet, providing vital services across a number of routes throughout 2026.
“Lessons were learned following the incident in June 2025, and remedial actions taken.
“The vessel is absolutely safe to operate on LNG, and the decision not to re-gas her following annual overhaul at the beginning of the year was purely due to our desire to get her back in service as quickly as possible.”
Appearing at Holyrood’s Transport Committee on Wednesday, Transport Secretary Stephen Flynn said he was not aware of the incident – which took place almost a year before he was appointed to the role.
Asked about the issue by committee convener Willie Rennie, Mr Flynn said he had not been briefed.
The minister told MSPs: “Over the summer, it may well be the case that the wide array of information that is shared with me in respect of ferry issues, that something that happened prior to my entering Parliament and taking on a Government position may have been conveyed to me as part of that, and I wouldn’t want to mislead the committee.
“But the specific news story to which you’re referring is one that I would have to go and familiarise myself with – I wasn’t listening to the BBC this morning, convener.”
Mr Rennie stressed that 82 passengers had been on board at the time of the venting, with Mr Flynn responding: “I didn’t see the news because I was FaceTiming my kids, but that’s a different matter.
“Look, I will make sure, convener, that subsequent to this committee, you get the information that you deserve in that regard.”
Transport Scotland director of ferries Chris Wilcock – who accompanied Mr Flynn at the committee – said he did not “have full details of that in front of me”, adding he wants to look into the specifics of the incident before commenting.
Mr Flynn added: “Let me be as candid as to say that I share your frustration in this regard and I will give you a commitment that I will make sure that you are appraised of your concerns subsequent to this committee.”
In a statement released later on Wednesday, Mr Flynn said: “I was not briefed on this incident, however details were shared with the former cabinet secretary for transport on 30 June 2025, in line with agreed processes.
“More widely, we depend upon the expertise of CMAL as the vessel owners and CalMac as the operator to advise and help with the decision-making process on vessel systems and operation.
“Through the Clyde and Hebrides Ferries Service contract, I expect them to follow the necessary legislation and processes when incidents such as these occur – including giving consideration as to how to keep parliamentary committees and local elected representatives routinely appraised of information.
“Following a joint investigation into the incident by CMAL, CalMac and Ferguson Marine, a number of lessons were identified.
“As a result, a minor design modification has been incorporated into MV Glen Sannox and MV Glen Rosa to provide an additional layer of safety and further enhance the resilience of the system.
“While these modifications were not required from a regulatory or operational safety perspective, they were implemented proactively as part of a continuous improvement approach and to further strengthen an already robust system.
“As promised, I will write to the Transport Committee to provide further details – and I have asked CalMac to do likewise.”