Martial Claudepierre, business development manager, Bureau Veritas said: “The ability to burn ethane as well as LNG to power these vessels is a major step forward in the use of clean fuels. We have worked with Evergas and the Danish Maritime Authority to verify and ensure that the use of ethane is at least as safe as required by the IGC and will not impair the engine compliance with MARPOL Annex VI.”

The Dragon vessels were originally designed with a dual-fuel LNG/diesel power utilizing two 1,000-cubic-meter LNG tanks on deck powering two Wärtsilä 6L20 DF main engines with a total of 2,112 kW power and two shaft generators with a total 3,600 kW power. The ability to also burn ethane was added to allow use of the cargo gas as the vessels are destined initially for transport of ethane from the U.S. to the UK Ineos refineries.

Commented Claudepierre: “Using ethane required extra engine room ventilation and additional gas detection, plus modifications to the main engines including a lower compression ratio, different turbocharger nozzles and de-rating of the engine to cope with the lower knocking resistance of ethane. But the gains in not carrying an additional fuel and in environmental performance from being able to burn clean fuel throughout the voyage are significant.”

Evergas is a Danish operating company established in 1883, wholly owned by Greenship Gas and JACCAR Holdings. It is involved in the seaborne transportation of petrochemical gas with a focus on ethane and ethylene, operating a fleet of petrochemical gas carriers. It has a large new-building program of ethylene, ethane and LNG multi-gas carriers.