World’s First S90 Methanol Engine Retrofit Completed On COSCO Container Ship

Everllence has confirmed the successful completion of the world’s first methanol engine retrofit for an S90-class vessel following the sea trials of COSCO SHIPPING LINES’ 20,000+ TEU container ship, COSCO SHIPPING LIBRA.

The achievement is a major step towards the decarbonisation of large container vessels. The project involved converting the vessel’s Everllence B&W 11S90ME-C two-stroke engine into an 11S90ME-LGIM (Liquid Gas Injection Methanol) dual-fuel unit.

The conversion was carried out by Everllence PrimeServ, the company’s after-sales division, in partnership with COSCO SHIPPING HEAVY INDUSTRY.

The retrofit covered all stages, from concept design and project management to installation, commissioning, and sea trials.

The successful sea trials confirmed that the methanol-powered engine met all performance expectations, making it a landmark achievement in the ongoing maritime energy transition.

Everllence had earlier commissioned a 4S90 testbed engine in Japan in early 2025 to support this development. The dedicated testbed was used to validate the S90 engine’s methanol performance under real operational conditions, helping speed up the readiness of this first large-bore conversion project.

Senior officials from Everllence PrimeServ in Denmark said the company was pleased to have supported COSCO SHIPPING LINES and COSCO SHIPPING HEAVY INDUSTRY in achieving this milestone.

Everllence has so far completed 26 dual-fuel conversions using various alternative fuels and has an even larger number of similar projects planned.

The company estimates that more than 300 vessels worldwide currently operate with S90-class engines, making them suitable candidates for future methanol conversions.

Company representatives added that while achieving full decarbonisation will need industry-wide cooperation, the COSCO SHIPPING LIBRA retrofit shows that large-scale conversions are both technically proven and commercially viable.

Reference: everllence

Source: Maritime Shipping News