Glen Sannox sea trials paused until next week

Glen Sannox, beginning its owner's acceptance trials on Monday

Final acceptance sea trials for the new CalMac ferry Glen Sannox have been paused until next week, after a false fire alert led to a loss of power at sea earlier this week.

A fire detector was inadvertently triggered on Wednesday, resulting in an electrical blackout and the subsequent shutdown of the engine systems.

The engines were later restarted and the ferry returned to Greenock under its own power, escorted by two tugs as a precaution.

Shipbuilder Ferguson Marine had hoped to resume the sea trials on Friday, but these have now been put back while fire alarms and other systems are tested.

The dual-fuel ship - the second largest and most complex ever built for the CalMac fleet - is now complete, with its liquefied natural gas (LNG) systems fully commissioned.

Owner's acceptance trials involving ferries procurement body CMAL, which leases vessels to CalMac, began on Monday.

The ship was put through its paces, accelerating to top speed and operating on both conventional marine gas oil and LNG.

During a test of the two anchors a fault was identified with one of them, but it was decided to continue with the trials.

Glen Sannox successfully berthed at its main destination of Brodick on Monday

On Tuesday, the ship was greeted by enthusiastic onlookers when it successfully completed a berthing test at Brodick on Arran, which will be its main destination when it enters service.

But on Wednesday morning, while sailing in the Firth of Clyde, the ship was left temporarily without power.

A spokesperson for Ferguson Marine said: "During day three of owner’s trials, MV Glen Sannox experienced a blackout.

"This was a result of inadvertently triggering a fire detector on board; although a false alarm, it ultimately resulted in the shutdown of the ship’s main propulsion. The ship was operating on MGO [marine gas oil] at the time.

“Checks of the main engines were undertaken and a soft restart followed. All systems were safely restarted without any adverse effects. However, trials were temporarily halted."

A spokesperson for ferry operator CalMac said sea trials and rigorous testing of systems and equipment were an essential part of any build process.

"The process has worked exactly as intended and helped identify an issue that can be rectified prior to delivery," the spokesperson added.

Ferguson Marine chief executive John Petticrew has updated MSPs and will give another update next week on whether there will be any impact on the planned delivery date.

The ship is currently due to be handed over by 14 October, after which CalMac will carry out several weeks of crew familiarisation before the ship carries its first passengers, possibly in December.

Glen Sannox and its sister ship Glen Rosa were originally due to enter service in 2018, but the project has been hit by design challenges and an acrimonious dispute between CMAL and the former owners of the Ferguson shipyard in Port Glasgow.

The shipyard was nationalised in 2019, but delays and cost increases have continued, with recent problems linked to the LNG systems.

The ships are the first LNG ferries ever built by a UK shipyard.

Glen Sannox will be the first new large vessel delivered to CalMac in almost a decade, and its arrival should relieve pressures on the ageing west coast fleet.

The first of four other large CalMac vessels being built in Turkey should begin to arrive next year, although a new delay to these was announced last week.

A second LNG ferry being built by Ferguson's, Glen Rosa, is currently due to be delivered next September, and will also be deployed on the busy Arran route.