Wärtsilä and Samsung Heavy Industries (SHI) have signed a joint development programme (JDP) agreement aimed at developing ammonia-fuelled vessels with 4-stroke auxiliary engines available for future newbuild projects. Both parties recognise the importance of future carbon-free fuels in the marine industry’s drive towards decarbonisation. The agreement was signed in July 2021. Wärtsilä has a leading role in developing engines for operation on future clean fuels, and has already successfully tested an engine running with a fuel mix containing 70% ammonia. The company anticipates having an engine concept capable of operating with 100% ammonia in 2023. According to SHI, the most likely initial newbuild targets for ships utilising ammonia fuel will be container vessels and very large crude carriers, operating with 2-stroke main engines and 4-stroke Wärtsilä auxiliary engines.