NYK works with two domestic shipyards to re-engine its steam turbine-powered Moss-type LNGCs

Leading Japanese LNG carrier operator NYK Line is starting a major conversion project to convert its fleet of old steam turbine-powered Moss-type LNG carriers to modern, more fuel- and environmentally efficient dual-fuel diesel propulsion. The shipowner has partnered with two domestic shipyards for the conversions: Namura Shipbuilding and Sasebo Heavy Industries.

Moss-type LNGCs use the spherical type of cargo containment system, designed and developed by Norway’s Moss Rosenberg, and was used on most Japanese-built LNG tankers delivered in the 1970s and 80s. These vessels were almost totally powered by steam turbine propulsion systems. However, today most new LNG carriers use the membrane-type cargo containment system, as offered by France’s GTT.

NYK’s vessels are to be fitted with WinGD’s X-DF two-stroke, low-speed, low-pressure diesel engines, which has become the standard solution for today’s LNG newbuildings.

In October last year, NYK Line was granted Approval in Principal (AiP) from the classification society ClassNK for converting steam turbine-powered LNGCs to dual-fuel diesel propulsion. This is the first AiP issued for such conversion projects.

Moss-type LNG cargo tanks are durable and can stand long-term use. In addition to improving fuel economy, the re-engining programme contributes to an efficient use of the ships’ resources.

The basic design of the conversion project has now been completed by NYK and the two shipyards.