A NEW fault with one of the ferries at the centre of Scotland's ferry fiasco could see it lose its green credentials.

Nationalised Ferguson Marine has confirmed that further issues with Glen Sannox means it will not initially run on LNG.

It will be operating on a diesel, single fuel system for at least the first nine months of its service.

Following this period, it may then have to be taken out of service to test its LNG system.

Scottish Conservative shadow transport minister Graham Simpson said: “This revelation just adds to the shambles around the building of this vessel which was supposed to be climate friendly."

Both Glen Sannox and Hull 802 were hailed as a step towards a greener future for Scotland's state owned CalMac ferry fleet as they were to be the first UK-built ships capable of running off LNG and marine gas oil.

LNG was seen as significantly cleaner and would help to reduce emissions to meet ambitious Scottish Government targets.

But both vessels remain languishing at Ferguson Marine's Inverclyde yard while the Scottish Government-controlled ferry owners Caledonian Maritime Assets Ltd (CMAL) await the long-delayed delivery that has raised questions over whether they will ever emerge.

The Herald: Glen Sannox Ferguson Marine, Port Glasgow.

They were due online in the first half of 2018, with one intitially to serve Arran and the other to serve the Skye triangle routes to North Uist and Harris, but are at least five years late, with costs soaring from £97m to nearly £350m.

In a new update, David Tydeman, chief executive officer of Ferguson Marine said: “Progress with the installation of the LNG system on the ship continues as planned within the programme although a technical design issue has just surfaced which will delay the commissioning of the LNG system.

“To comply with Classification and safety related rules applying to the bunkering operations, bespoke vacuum sensors are required in the system, and these are made to order, unfortunately, on a 36-week lead time from the supplier.

“They advise they are affected by global supply chain issues and hence, whilst we hope for a faster supply, it is unlikely to be much better.”

He continued: “I raised this with our board earlier this week and with SG & CMAL today. Our emerging proposal to deal with this, is to maintain the programme for handover of the ship by the end of May latest, initially running only with the diesel, single fuel system.

“The LNG system will be essentially complete on ship by this time and hence we believe we can install the sensors later whilst the vessel is in service during next summer.”

Mr Simpson added: “Surely it was known these sensors would be needed but now we are going to be left with a gas guzzling, climate busting ferry for at least the first nine months of its service.

“No doubt this will also increase the already spiralling cost of the Glen Sannox.

“The SNP's handling of this project has been a disgrace from start to finish. We need a public inquiry to establish what went wrong and why.”

A Scottish Government spokesman said: "Ferguson Marine has informed the Scottish Government of an issue relating to the Liquefied Natural Gas (LNG) system for the MV Glen Sannox.  Ministers are seeking urgent options on the next steps and expect all possible measures to be taken to deliver the vessel to serve islanders as soon as possible.”