The new reference for LNG propulsion

United Arab Shipping Company (UASC) is adding eleven 14,500 TEU (A14) and six 18,800 TEU (A18) super-efficient, eco-friendly container vessels to its fleet. The new vessels have been ordered from Hyundai Heavy Industries (HHI) and Hyundai Samho Heavy Industries, respectively, will be classed with DNV GL and are to be commissioned between late 2014 and mid-2016. The design and consulting bureau TECHNOLOG Services GmbH, Hamburg, consultants to UASC since 1997, have supported the UASC Newbuilding Team throughout the project.

Unrivalled efficiency
Both vessel types share a common design concept. Engineered and equipped for fuel economy, they have hulls optimised to UASC’s intended operating profile, and BTF energy savers. The new ultra-long-stroke, ultra-slow-running Hyundai B&W S90ME-C10.2 engines will provide the best possible propulsion efficiency. Mitsubishi waste heat recovery systems and Siemens shaft generators and shaft motors will ensure maximal energy utilisation. The vessels are being fitted with highly sophisticated, comprehensive Kongsberg Integrated Vessel Control systems as well as power and energy management systems for continuous performance monitoring.

A MacGregor total cargo solution ensures optimised container intake. Even when powered by conventional fossil fuel these ships will achieve very good EEDI and CO2 values. What is more, all vessels will be pre-configured for dual-fuel operation, encouraged by good progress in the establishment of bunker logistics in ports along the main trading routes and confirmed LNG bunker availability by mid-2016. LNG fuel systems can be retrofitted as soon as the market conditions are right.

Taking the lead
Fuel consumption is the biggest cost driver in shipping. At the time they are put into service, UASC’s new vessels will have to be highly competitive compared to conventional ships, and remain so for years to come. They must also comply with the stricter rules of IMO MARPOL VI regarding SOX, NOX, diesel particle and CO2 emissions and be ready to operate in a growing network of Emission Control Areas. By opting for LNG rather than scrubbers and SCRs, UASC has taken the lead in promoting LNG as a fuel for mega-sized container carriers.

Technical concept
Some of the tougher questions in the project related to the intended navigation zones (ECA vs global), endurance and appropriate LNG tank sizes, tank design and costs, tank location inside the ship, economy of retrofitting, selection of the fuel gas supply system (F.G.S.S.), or the best position for the bunker stations and vent mast to minimise the loss of precious container stowage space. From the retrofitting perspective it became obvious that the cargo hold directly in front of the engine room would be the best location for the LNG tank because of short piping routes. A Type B tank will have the greatest stowage density compared to smaller, cylindrical Type C tanks, and conserve valuable container slot space. It will be positioned between the longitudinal hold bulkheads, maintaining a B/10 safety distance between the outside insulation and the shell.

Thanks to the close cooperation between the UASC Newbuilding Team, HHI, Hyundai Engine & Machinery Division (HHI-EMD) and Japan Marine United Corporation (JMU), the design for the self-supporting prismatic-shaped IMO LNG Type B Tank (IHI-SPB tank) has been completed, and the Approval in Principle (AiP) for the LNG plant design obtained from DNV GL.

The open question: bunkering
Earlier this year, DNV GL released its ”RECOMMENDED PRACTICE – Development and operation of liquefied natural gas bunkering facilities”, which focuses on safety and risk assessment. International standards for LNG bunkering facilities have yet to be established. Meanwhile, DNV GL’s LNG Ready Service helps owners ensure their newbuilds can be
converted to LNG fuel rapidly and cost-effectively. The UASC project will serve as a reference for other large-scale LNG applications in containership newbuilding and conversion projects.
Source: DNV GL