JUNE 23, 2016 —The first dual-fuel two-stroke engine using the low-pressure X-DF gas admission technology developed by Winterthur Gas & Diesel (WinGD) has passed the final milestone in its passage from a technical concept to commercial operation as a marine main engine.
The 5-cylinder, 500 mm bore, Wärtsilä RT-flex50DF engine is installed as the main engine driving a single propeller in the Ternsund, a low emissions 15,000 DWT chemical tanker.
Ternsund was built by AVIC International Ship Development (China) Co., Ltd. (AVIC SHIP), Shanghai, China and completedby AVIC Dingheng Shipbuilding Co. Ltd, Jiangdu, China for Terntank Rederi A/S, based in Skagen, Denmark.
The ship underwent its sea trials from May 22 to 28 and is scheduled to be delivered by the end of June.
During the sea trials, the Wärtsilä 5RT-flex50DF engine, rated with a maximum power of 5850 kW at 102 rpm, was run continuously for several days in its gas mode and a series of automated fuel changeovers to gas mode and back were executed.
In addition, as customary in sea trials, the engine was run at a range of load points in both gas and diesel mode, including a high load level set to fully exploit the sea margin of the Ternsund with its hull in new condition without fouling.
With an overall length of 147 m and a beam of 22 m, the 15,000 DWT Ternsund is a twin-hull chemical tanker designed to meet Ice Class 1A. It is the first of four vessels ordered by Terntank from AVIC Dingheng Shipbuilding.
The Wärtsilä 5RT-flex50DF engine is matched to a design speed of 14.5 knots.
It was delivered to the shipyard in October 2015 by WinGD's engine manufacturer Yuchai Marine Power Co., Ltd. (YCMP) based in Zhuhai, China.
Destined to operate predominantly in northern European waters, the Wärtsilä 5RT-flex50DF engine will enable the Ternsund to meet the strict SOx limits in Sulfur Emission Control Areas (SECAs) due to the extremely low sulfur content of natural gas. The X-DF technology also enables compliance with IMO Tier III NOx limits in gas operation without additional exhaust gas after-treatment.