DU delivered the dual fuel engine “5RT-flex50DF”, which DU manufactured as the first commercial engine, on 18th November 2015.
This “5RT-flex50DF” is a main engine for an asphalt tanker built at Besiktas Gemi Insa A.S. in Turkey and DU has already received another order for the 2nd vessel.

The dual fuel engine “X-DF” is adopted not only to LNG carriers but also LNG burned commercial vessels built in South Korea and China. As of today, 33 “X-DF” engines have already been ordered in the world.

DU has a full scale test engine “W6X72DF”, the largest one in the world, at DU Aioi works, and has been developing the performance in partnership with Winterthur Gas & Diesel, Wärtsilä and IHI.

Advantage of “X-DF” engines
1. X-DF applies the pre-mixed lean burn technology and can meet IMO Tier-Ⅲ requirement.
2. X-DF has advantages of lower Capex and Opex due to no requirement of a high pressure compressor.
3. For safety concerns, X-DF uses low-pressure LNG. (<16bar)
4. X-DF can switch from gas mode to diesel mode immediately.
5. X-DF is based on the low-speed two-stroke engine which is much proven in marine use.

Related topic is as follows,
*Development of low-pressure dual fuel engine.