The delayed and over-budget ferry the Glen Sannox has successfully completed the first phase of sea trials, its manufacturers at Ferguson Marine have said.
The vessel sailed under its own power for the first time earlier this week and the shipyard says its propulsion and manoeuvring capabilities passed tests overseen by Lloyds Register, which certifies ships.
However it remains unclear when the vessel’s liquefied natural gas (LNG) system will be ready as the shipyard has faced delays from suppliers.
Both the Glen Sannox and sister ship the Glen Rosa are designed to be “dual fuel” – running on LNG and traditional bunker fuel in order to keep emissions down.
The Scottish Government has previously said all systems including the LNG propulsion will need to be completed before the ferry-owning agency Caledonian Maritime Assets Ltd (CMAL) can take delivery.
During the sea trials, Glen Sannox only used marine gas oil diesel rather than LNG.
On Friday, Ferguson Marine said the Glen Sannox achieved a maximum speed of 16.7 knots, confirming it can operate at the planned speed of 14.5 knots.
David Tydeman, chief executive at Ferguson Marine in Port Glasgow, said: “The results of this first phase of trials have been overwhelmingly positive, clearly demonstrating the advanced technology which MV Glen Sannox will bring to the CalMac fleet.
“Next steps for the vessel will be a return to the Ferguson Marine quayside, where she will undergo further outfitting and LNG system work before a trip to the dry dock in early April.
“After that will come what’s known as ‘owner’s sea trials’ with CMAL as representatives for Scottish ministers on board.
“In April and May, she will also undergo endurance tests – when she will operate at higher speeds for longer periods of time.”
Costs for the Glen Sannox and Glen Rosa have more than tripled to at least £360 million and they are expected to be delivered around six years late.
Further tests will need to take place before the Glen Sannox, which has capacity for 852 passengers, can begin serving the Arran route.