Plans for the introduction of the 'eco-friendly' vessels at the centre of Scotland's ferry fiasco have been thrown into new chaos as it has emerged two key Scots ports will not be capable of providing the 'green' fuel.

In what is being described as a "new ferry shambles", the Scottish Government has confirmed that there is no budget to provide the necessary port facilities for Liquified Natural Gas (LNG) at either Ardrossan or Troon in 2024/25 - even though the two ferreis are due to start carrying passengers by May next year.

It comes as it emerged that Ardrossan may not ever be used to take the ferries despite the green light being given for upgrade works by the current First Minister - six years ago, three years after the contracts were signed to have Inverclyde shipyard firm Ferguson Marine build the two ferries.

The dual-fuel ferries Glen Sannox and Glen Rosa which were meant to be identical, were lauded by then First Minister Nicola Sturgeon as the 'sustainable' ferries that would "contribute to Scotland's world-leading climate change goals".

They 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 liquefied natural gas, or LNG, as well as conventional diesel.

READ MORE: CalMac: Failing Scots ferry set to be sidelined for three months

The vessels, still to be completed at Ferguson's were due online in the first half of 2018, with both now due to serve Arran, but are at least six years late, with costs expected to be quadruple the original £97m contract.

Glen Rosa was meant to be delivered to CalMac in August 2018, but that is currently scheduled for May 2025. Glen Sannox, was launched by Nicola Sturgeon nearly seven years ago and is due for delivery in the spring.

But the dates of arrival have been constantly in a state of flux as their construction has been plagued by design challenges, cost overruns and delays.

The Herald previously revealed that the costs of the project to upgrade the mainland port of Ardrossan including the installation of LNG infrastructure for what is one of Scotland's busiest ferry routes, which remains in huge doubt had doubled.

Then business minister Ivan McKee insisted in September, 2022 that the harbour and port infrastructure at Ardrossan would be ready to take the two lifeline ferries when they finally set sail after being built at the nationalised Ferguson Marine shipyard in Inverclyde.

The Herald:

But the Scottish Government-owned ferry operator CalMac has already been planning to use Troon rather than Ardrossan for the two ferries that will serve Arran. That was when it was hoped that the first of the vessels would be ready for passengers in the Spring of last year.

Peel Ports, which owns Ardrossan, has already shut down one of its two berths permanently in the wake of safety issues - raising further questions about its viability for the new ferries.

A Scottish Government letter, seen by the Herald has now confirmed there is no budget in 2024/25 to provide any LNG infrastructure and no plans at all to put a port storage tank and associated infrastructure at Troon.

Instead they have advised, that while at Troon, the fuelling is due to be undertaken at sea from a tanker directly to vessels but that has led to concerns to major delays to vessels because of extended fuelling time and fears they will be vulnerable to the Scottish elements.

It is also not considered a green choice.

The European Federation for Transport and Environment, commonly referred to as Transport & Environment, a European umbrella for non-governmental organisations working in the field of transport and the environment, promoting sustainable transport in Europe believe the ferry engines for Glen Sannox and Glen Rosa are the worst for methane greenhouse gas leakage.

Analysis by the International Council on Clean Transportation revealed that in 2021, some 82% of methane emissions from international shipping could be traced back to liquefied gas tankers, primarily LNG carriers.

The Herald:

Shadow cabinet secretary for net zero, energy and transport Douglas Lumsden who has been seeking answers over the LNG budget said: “It is incredibly concerning that there are currently no plans for a storage facility at Troon which leaves the running of these vessels completely at the mercy of the elements.

“Supplying our ferries with LNG direct from tankers means they could be subject to further delays if a tanker cannot arrive on time or has to leave before the ferry it’s supplying has arrived.

“No community has suffered more from the SNP’s ferry scandal than those living in Arran – and yet even when the long-delayed Ferguson Marine vessels finally come into service, it seems there will still be question marks over the reliability of the ferry service they receive.

“No wonder they, and Scotland’s other island communities, feel utterly betrayed by this shambolic SNP government.”

READ MORE: Secret Scotland: Ministers stand firm in blocking release of ferry fiasco costs

A ferry user group official said that the green credentials of the ferries had already been "well and truly shattered" by evidence revealed in the Herald and added: "The fact there is no money being committed to LNG facilities full stop is another symptom of the shambolic mismanagement there has been in delivering lifeline services to the islands."

CalMac admit in its customer messaging that truck-to-ship bunkering is "not considered a sustainable solution" which will meet the long-term demands of the new ships.

They say the typical transfer rate is too slow – typically between two and two-and-a-half hours for 20 tonnes. When the delayed fixed tank is in operation, the time will drop to between 45 and 60 minutes. A full tanker of Marine Gas Oil is approximately 28 tonnes and can be transferred in about 45 minutes.

Scottish Government sources have confirmed that the full business case for the Ardrossan project remains incomplete and that there is even uncertainty over the project costs, consequently, the project has still to be put out to tender.

The issues surrounding how the cost - which in 2022 was estimated at £40m - would be divided between the Scottish Government quango Transport Scotland, the harbour owner Peel Ports and North Ayrshire Council.

It has been further confirmed that the Scottish Government has not made any decision over whether Ardrossan would remain the mainland port for the Arran service - placing serious question marks over the upgrade project.

The Ardrossan Steering Group was told by Transport Scotland officials that as of May, the estimated cost is thought to have doubled which it is said was "reflective of the market conditions within the construction industry".

But there has been since been further discussions amongst funding partners over the required project scope - which could set the costs even higher.

According to one letter from the Scottish Government to the Ardrossan Harbour Task Force, made up of the potential funding partners and co-ordinated by the Scottish Government's Transport Scotland agency, concerns about the integrity of the quay walls have been heightened following recent structural failures to parts.

The walls were expected to provide support to an LNG tank, which would be used to help fuel the vessels.

Further concerns about Troon becoming a likely long-term base, surround travelling times rising from 55 minutes to an hour and 20 minutes and a predicted 20% cut in sailings.

A Transport Scotland spokesperson said: “It is inaccurate to suggest these vessels will be more vulnerable to fuel shortages. Dual fuel options reduce risk, increasing the resilience of the vessels while providing opportunities to reduce emissions.

“The vessels will initially operate from Troon where new infrastructure and passenger facilities have been put in place to support ferry service when it temporarily relocates. Vessels at Troon will be bunkered by LNG tanker until a more permanent arrangement is secured.

“The plans for the Ardrossan harbour redevelopment include an LNG storage facility and will be financially accounted for under wider ports investment in future years.”

The Herald previously revealed that ministers have admitted they are unable to check on the levels of greenhouse gases that will be pumped into the atmosphere by the much delayed and over-budget vessels.

The Herald: Ardrossan Harbour

Transport & Environment say using LNG as a marine fuel goes against the Global Methane Pledge launched at the United Nations Climate Change Conference, commonly known as COP26, in Glasgow in November 2021 that aims to reduce methane emissions by 30% by 2030 and is against advice from institutions such as the World Bank.

They say LNG is mostly methane, a greenhouse gas around 80 times more powerful than CO2 in the short-term and 30 times worse in the long term. It has been described as a "greenwashing pill".

Transport Scotland said there were many vessels in the world which are running with dual fuel engines and that it was "well established and proven technology".

The adoption of LNG as a fuel by ships stems from the fact that it is said to contain less carbon and little sulphur compared to traditional marine fuels. LNG can thus lower CO2 and sulphur oxides (SOx) emissions that ships would normally emit. LNG marine engines are also set up in a way that emits less nitrogen oxides (NOx) emissions.

When LNG is burned as a fuel, it releases energy and produces carbon dioxide (CO2) and water vapour, along with smaller amounts of other pollutants.

While CO2 is a significant greenhouse gas, burning methane releases less CO2 compared to other fossil fuels, making in theory LNG a relatively cleaner-burning fuel.

Transport & Environment say that while the industry was quick to tout the benefits of LNG, the relatively damning methane slippage problem was swept under the carpet, as well as leakages from on-shore infrastructure associated with the fuel's production, transportation and storage.

If methane is released in air – even in very small amounts – its impact on climate change is disastrous.

Methane is a potent greenhouse gas, with a higher warming potential than CO2 over a shorter timeframe. Any methane slip can contribute to greenhouse emissions and impact the overall environmental footprint of LNG.

Transport & Environment say the four stroke engines that are currently the choice for Glen Sannox and Glen Rosa has the highest methane slippage.