Concerns have been raised that regulatory clearances for two ferries at the centre of Scotland's ferry fiasco were not made in good time - after it emerged they failed to comply with safety rules that are seven years old.

Further delays and rising costs are expected in relation to Glen Sannox and Glen Rosa that remain under construction at nationalised Ferguson Marine.

Safety clearances for Glen Sannox and Glen Rosa were rejected on June 1, sparking a redesign.

Among the issues to be resolved surrounds the installation of the evacuation routes on Glen Sannox and Hull 802 in order to satisfy the Maritime and Coastguard Agency (MCA), which is responsible for implementing British and international maritime law and safety policy.

It has emerged that according to MCA, Ferguson Marine approached the safety body about the escape routes on April 11, 2023 and the plan was rejected sparking a redesign.

The issues related to 2016 cargo ship rules and linked to the International Convention for the Safety of Life at Sea (SOLAS) which states the requirements for means of escape.

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The issues relate to requirements over additional protection to ladders and stairways as well as fire shelters and a means of escape from workshops within machinery spaces.

The Herald: Ferguson Marine and (inset) David Tydeman

David Tydeman, chief executive of nationalised Ferguson Marine has said that the issues had been the result of the MCA reassessing cargo ship rules.

The MCA in answer to a question about whether there were any rule changes said there had not been any. But they said there had been an "interpretation" of what was required and indicated that that could already be seen in other CalMac vessels.

It said that the issues came as part of an approval process during the build, where they identify areas of non-compliance. It is then for the designer or builder to then decide how to address the matters.

Edward Mountain, the Highlands and Islands MSP, the former convenor of the Scottish Parliament rural economy and connectivity committee which branded the ferry fiasco management process a "castastrophic failure" in an inquiry and has been closely following the progress of the ferries said: “On initial investigation, this is deeply complacent or hugely incompetent, or perhaps a mixture of both."

The convener of Holyrood's transport committee added: "Naval architects will support the argument that the MCA should have been part of the sign off on the drawings and involved in every stage of it so there were no surprises on completion, which is what we’ve got.”

The work meant planned sea trials of the Glen Sannox have been delayed until the first quarter of next year.

CalMac had expected Glen Sannox to be handed over in December 2023, and Glen Rosa in December 2024. They say that once handed over there will be a two month period where they will carry out crew familiarisation and network trials.

The latest update from the Scottish Government-owned Ferguson Marine shipyard raised further fears that the Glen Sannox would not be available for the start of the 2024 summer season.

Mr Tydeman, chief executive of the nationalised Inverclyde shipyard firm had previously stated he was optimistic that Glen Sannox should be available to passengers in spring 2024.

The delayed second vessel, only known as Hull 802 which which was supposed to be online in the last reschedule in the autumn of 2024 having already been delayed to the end of March 2024, had been pushed back to November, 2024. The contract backstop was stated as being at the end of December 2024.

Both vessels were due online in the first half of 2018, with both now to serve Arran, but are at least five years late, with costs expected to be quadruple the original £97m contract.

Mr Tydeman said in August in relation to the issues: "The MCA have reassessed the application of 'cargo ship' rules to the crew spaces of passenger ferries (on a broader basis than just Ferguson and Glen Sannox/802) and for the last two months we have been working to close the impacts of this and some other approvals issues.

The Herald: David Tydeman of Ferguson Marine

"We have been designing and planning the necessary modificiations to some doorways in crew corridors and three additional staircases between decks 5,6 and 7. We have one issue to finalise and hope to reach final agreement with the MCA within the next two weeks so that we can carry out all the modifications before Glen Sannox moves to the dry-dock just before Xmas."

He added: "This means the sea trials will move into the first quarter of the new year and the commissioning of the liquefied natural gas system at Troon (which must be done after dry docking) will also be moved to after Christmas".

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It comes after ministers were accused of wasting millions over major changes to plans for the launch of vessels.

A ferry user group official said that it "beggared belief" that the issues had not been spotted and dealt with sooner.

"While the building of ferries is accepted to be a hugely complicated affair, it is incredible that safety issues relating to established rules are discovered so late in the day."

David Tydeman, chief executive of Ferguson Marine (Port Glasgow) said: “[Ferguson Marine] is well aware of the rules and dates as noted by MCA. Until late April 2023, we were proceeding on the basis that past interpretations would also be accepted on Glen Sannox and Glen Rosa. This was partly based on exemptions for other issues having been granted in writing for both ships by the MCA during 2021/2022.

“However, between April and June this year, it became clear, through discussions with the local MCA Glasgow-based surveyor and his reviews with the MCA Southampton office, that changes would be required. These changes were not finalised until June. Fundamentally, the issues relate to the structural design of the ships completed by FMEL between 2015 and 2017."

He said more details would be provided at a later date.

It comes as the Scottish Government-owned ferry owners and procurers Caledonian Maritime Assets Limited warned two months ago that the work rate would have to "increase considerably" to meet its completion deadline.

The Herald:

A report of a CMAL board meeting in June said that chief executive Kevin Hobbs had already declared disquiet over the progress of Glen Rosa. It stated: "KH [Kevin Hobbs] noted that [Glen Rosa] has had more limited progress that MVGS [Glen Sannox] and the level of activity would need to increase considerably in order to achieve the target delivery date of December 2024."

It also indicated the board had doubts about the yard’s previous hope of completing the ferry by summer 2024. They stated: "We have raised our concerns about this ambitious target given the lack of progress on this vessel, given the resources are being focused on MVGS [Glen Sannox]."

Wellbeing economy secretary Neil Gray has so far been unable to explain the depths of the delays in relation to the new issues.

He has told MSPs that he was unaware of any issues when he gave his last parliamentary update, understood to have been in May.

He said the MCA involvement was no "minor thing" and that it would be "inappropriate" for him to intervene.

He added earlier this month: "The MCA’s decision making on the safety of crew escape from the ships – this is pretty fundamental to whether or not the design of the ferry allows it to sail. It’s not an inconsequential matter."