The handover date for Arran's new ferry The Glen Sannox has been pushed back yet again.

Shipyard Ferguson Marine says its new official handover date will be September 30, despite last month saying it hoped to deliver the vessel in the week beginning August 19.

It is already six years behind schedule.

The state-owned shipyard has identified more areas which need work as it continues to wrestle with problems around the installation of a liquefied natural gas (LNG) fuel system, something it has been dealing with since last year.

Both Glen Sannox and its sister ship, Glen Rosa, are designed to run on both traditional marine gas oil and LNG - becoming the first ferries built in the UK to do so.

However, Ferguson Marine says the September 30 date could be pulled forward if it makes good progress and successfully completes further sea trials.

The latest delays come as CalMac prepares to retire one of its oldest vessels, MV Hebridean Isles, in November. The vessel was often used as back up for the Arran service over the years.

Ferguson Marine's interim chief executive John Petticrew wrote to the Scottish Parliament's transport committee on Friday to provide one of his regular updates.

He said: "We have, regrettably, identified an additional number of areas which require to be completed on the vessel before we can proceed to acceptance trials.

"The majority of these works will have to take place in relatively small engine spaces, which are already delayed by the prolonged installation of the LNG system, due to the complexity of installation and need to examine the integrity of the pipework."

This would lead to increased workforce congestion on parts of the vessel, he said, meaning a re-evaluation of health and safety standards is needed.

Mr Petticrew continued: "As I'm sure you'll agree, ensuring the safety and wellbeing of our team is our number one priority, especially in an industry like this, where there is simply no room for half measures or cutting corners.

"Following a review of these challenges, we are conscious of the risk associated with nearing completion of MV Glen Sannox's 'first-in-class' dual fuel design and we therefore signal an official handover deadline of September 30 2024.

"This date, which would allow us breathing space to consider any unknown issues during LNG/owners trials and post-trial inspections, could however be pulled forward should we prove the vessel with no issues raised at sea trials or during the final sign-off procedures."

He said he would update the committee on the cost implications of the latest changes.

Current cost estimates for Glen Sannox are between £145.5 million and £149.1m and it is hoped the cost for Glen Rosa will be kept below £150m.

Now six years late, the total bill will be three times the original £97 million price tag.

Also on Friday, CalMac confirmed it will retire the MV Hebridean Isles in November after almost 40 years of service.

Affectionately known as Heb Isles, the 85m-long ferry has mainly served Islay in recent years.
The first of four new major vessels being built in Turkey, MV Isle of Islay will operate the route when she enters service later this year.

Craig Ramsay, CalMac's fleet management director, said: "If the Heb Isles were to be retained, she would require a significant programme of work in overhaul due to her age and general condition and this would keep her out of service for months.

"Vessels become a part of the fabric of the island communities they serve, and CalMac colleagues and islanders, particularly on Islay, will be sorry to see the Heb Isles exit the fleet after a long period of service.

"That's why we are keen to mark her departure in some form come November."