From an Article by Mike Corkhill, LNG World Shipping, July 26, 2018
The first of a pair of very large ethane carriers (VLECs) under construction at the Dalian Shipbuilding Industry Co (DSIC) shipyard for Evergas has been floated out from its building dock. The occasion was accompanied by cutting first steel for the second of the pair.
The two 85,000 m3 ethane carriers will be chartered to INEOS Trading & Shipping to carry ethane from the US Gulf to China. SP Chemicals has contracted to buy the cargoes that the first of the two VLECs will transport, for use as feedstock in a new 650,000 tonnes per annum ethylene cracker it is building at Taixing in China’s Jiangsu province.
The two newbuildings represent an extension of the ethane delivery capabilities of the shipping and trading arm of the giant INEOS petrochemical group. INEOS Trading & Shipping already charters eight 27,500 m3 Evergas-operated, Dragon-class ethane carriers for the transatlantic delivery of competitively priced US ethane to group ethylene crackers at Grangemouth in Scotland and Rafnes in Norway.
The first of the DSIC newbuildings is due for completion in Q1 2019. The pair, like the Dragon-class ethane carriers, are being built to the semi-pressurised/fully refrigerated (semi-ref) gas carrier design.
The vessels represent the first application of the semi-ref design to very large gas carriers and will be fitted with the largest IMO Type C pressure vessel cargo tanks ever constructed. IMO Type C gas tank containment systems do not require a secondary barrier.
Three of the four cargo tanks on each VLEC are being built to the Star Tri-lobe configuration to help optimise the cargo-carrying space available when the Type C containment system is chosen. The largest of the tri-lobe units, which consist of three cylinders combined into one, on the DSIC VLECs has a capacity of 23,000 m3 and weighs 1,800 tonnes.
For a given hull envelope, the tri-lobe solution offers a 20% increase in cargo space compared to using bi-lobe tanks. The Star Tri-lobe design was developed by JHW Engineering and Contracting in co-operation with the Hartmann Group. JHW, like Evergas, is part of the Jaccar Group.
Each of the DSIC VLECs will be powered by one of MAN’s M-type electronically controlled gas-injection (ME-GI) main engines. MAN designates the ethane-burning version of the ME-GI engine as its ME-GIE unit. Each vessel will be provided with a pair of deck-mounted cylindrical tanks to hold ethane fuel.
MAN Energy Solutions has supplied the 6G60 ME-GIE engine for each VLEC complete with its newly developed pump vaporiser unit (PVU), a device that ensures the supply of high-pressure gas to the ME-GIE engine in the correct manner. Providing full pump redundancy, the PVU costs less and occupies less space than previous fuel-gas supply systems for MAN’s high-pressure engines.