NEW concerns have been raised about the delivery of Scotland's ferry fiasco vessels following further issues with "design gaps" and the ability to run on green fuel.

Nationalised Ferguson Marine insists that any issues with two ferries which remain at the Inverclyde shipyard will not change the revised delayed schedule for delivery.

But they have admitted thatthey will use late February as a "milestone to reassess confidence of meeting the target delivery dates".

Both Glen Sannox and the unnamed Hull 802 were due online in the first half of 2018, with one initially 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.

Ferguson Marine confirmed that further issues with Glen Sannox meant it will not initially run on LNG - which produces 40% less carbon dioxide (CO2) than coal and 30% less than oil, which makes it the cleanest of the fossil fuels.

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.

READ MORE: Workforce fears Scots fiasco ferries won't ever sail

In a new update, David Tydeman, chief executive officer of Ferguson Marine said: that they continue to find design gaps on Glen Sannox but "nothing yet significantly affecting the critical path".

The Herald: DAVID TYDEMAN CEO OF FERGUSON'S

Issues with running LNG surfaced in October when it was discovered that bespoke LNG vacuum sensors which were crucial for the safe running of Glen Sannox had not been ordered.

Ferguson Marine expected it would take 36 weeks to get LNG parts delivered through Finnish firm Wärtsilä because of global supply issues meaning it would be on site by July, 2023 - up to three months after Glen Sannox was due to be complete.

Mr Tydeman says that timeline has "slipped back" but did not give any details of rescheduling.

On the LNG parts delivery he said: "We will continue to try to expedite these and decisions on commissioning timing can be best made in February/March, 2023 with Scottish Government/Caledonian Maritime Assets Limited/CalMac once more definite information is available.

Ferguson Marine has admitted that an "oversight" meant that crucial vacuum sensors required for the green fuel system had been forgotten about since 2021 - two years after the Inverclyde-based yard firm was nationalised when the Jim McColl-led firm went into administration.

The further issues meant Glen Sannox will not initially run on LNG.

The Herald:

Scottish Conservative shadow transport minister Graham Simpson MSP said: “Despite the claim by Ferguson Marine’s CEO that there is nothing ‘significantly affecting the critical path’ for finishing the ferries, islanders will be concerned by the issues he identifies.

“These all have the potential to delay delivery even further. Given the SNP’s incompetent handling of this business, and with this vital lifeline service already more than five years late, few people will be prepared to take these assurances on trust.”

Glen Sannox is due to be completed in May, 2023, while Hull 802 is due only in March, 2024.

Mr Tydeman said they were "managing the continuing list of 'unknown-unknowns' that arise on Glen Sannox and continue the planning for a more efficient outfitting and commissioning on 80s, learning from Glen Sannox".

He said that February would "also be a good opportunity to re-assess 802 and the structural consolidation progress, design cleansing process and the progress with fit-out".

It comes after workers trying to get the vessels ship shape fear they will never be considered fit to take to the seas while new problems over their delivery emerge.

Concerns from within the workforce of the nationalised Ferguson Marine presented to an MSP delegation come as the latest risks assessments raised continuing 'high' level risks over CMAL, the taxpayer-funded company which owns and procures ferries, not accepting the vessels if faults are not completed to their satisfaction.

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.

A Scottish Government spokesperson said: "The Scottish Government’s priorities have always been the completion of the two ferries, securing a future for the yard and its workforce, and supporting our island communities that rely on this type of vessel on a daily basis.

"We continue to urge Ferguson Marine to do all it can to bring down costs and meet the agreed delivery schedule.