Sweden’s Stena Line says it will convert two more of its vessels to be able to use methanol as a fuel.

The two new conversions will be the 30,285-gt Superfast VII and Superfast VIII (both built 2001), which run between the UK and Ireland.

Two of each vessel’s four engines are to be converted to run on methanol alongside marine gasoil. Fuel systems, bunker tanks and other supporting systems will be adapted or installed.

The company also has an orderbook for newbuildings at CMJL (Weihai) yard in China, including a pair of its self-branded NewMax that will be able to use methanol fuel.

The Stena Superfast VII and Stena Superfast VIII are switching class society to Lloyd’s Register ahead of the conversion.

European shipping data site Equasis suggests the Stena Superfast VII switched from ABS in February, with the second vessel clearly about to move.

The ferry operator began its interest in methanol in 2015 by converting one of the four Wartsila engines on board the 51,800-gt Stena Germanica (built 2002) to be dual-fuelled, before continuing to the other three over subsequent years. It remains one of the few methanol conversions in the industry.

The conversion was due to the need for vessels in the northern European emission control areas to meet new limits on sulphur in fuel.

Stena announced last year along with engine maker Wartsila its intention to run further methanol retrofits in 2025 but gave no details on the number of vessels.