In 2012 Caledonian MacBrayne Assests Ltd (CMAL) began the process of  defining the parameters and arrangement for the ferry that would become the first UK LNG Ferry. It was required to operate in  the majority of the Scottish Highland and Island ports serviced by operator Caledonian MacBrayne Ltd. (CalMac).  From the very first discussions with potential suppliers, the vessel was to be an LNG fuelled vessel.  CMAL and CalMac had already shown their clean energy credentials in the building of two 43m Ro-Ro hybrid vessels but,at the time, there were few conventional LNG Fuelled Ro-Ro Ferries. Restricted water double ended ferries were the common LNG ferry application.

Initial design development for the first UK LNG ferry was further progressed in 2014 to allow CMAL to enter into an EU tendering prequalification process.  Ferguson Marine Engineering Limited (FMEL) successfully prequalified and, in 2015, participated in the resulting full tendering process. Houlder was engaged with FMEL to support them with development the tendering design and technical documentation during this phase.

This proved successful and a contract was signed to build two vessels – hull no. 801 and 802 –  in late 2015.  The principal particulars of the ferries are as below.

• Length Overall – 102.40m
• Length Between Perpendiculars – 97.80m
• Breadth Moulded – 17.0m
• Depth to Main Deck – 5.95m
• Depth to Passenger Deck – 12.20m
• Normal Operational Draught – 3.40m
• Design Draught – 3.60m
• Scantling Draught – 3.70m
• Deadweight @ 3.40m (approx.) – 900 tonnes
• Deadweight @ 3.60m (approx.) – 1180 tonnes

On contact award, Houlder was appointed by FMEL as naval architects for the basic design and that work, and further scopes involving more detailed design, continued as the build of the vessel progressed.

In November 2017, the first UK LNG Ferry, christened MV Glen Sannox (pictured), was launched on the Clyde by Scottish First Minister, Nicola Sturgeon. The second is due for launch next year.