Glen Sannox ferry leaked flammable gas during crossing with over 80 passengers on board

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.

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, 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.”

Rennie stressed that 82 passengers had been on board at the time of the venting, with 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 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.

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.”