LNG tank retrofit for large boxships gets DNV GL approval

Concept designed to make it easier for owners to refit existing ships with an LNG fuel system.

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Updated on 08 Dec 2017 11:14 GMT

Classification society DNV GL has presented GTT and its partner Technolog with a General Approval for Ship Application (GASA) statement for the retrofit of very large container vessels (VLCVs) with exoskeleton membrane LNG tanks.

LNG membrane tanks generally offer more efficient space utilisation for cargo storage and as fuel tanks. The exoskeleton concept offered by GTT, and developed in partnership with Technolog, consists of a structure that can be pre-built on the dock and then installed as a complete unit in the hull of the vessel. This greatly reduces the construction time of the ship at the yard and eliminates the necessity to go into dry dock.

The solution has been developed for VLCVs with a capacity of 14,000 to 18,000 TEU and is designed to make it possible for owners to more easily refit existing vessels with an LNG fuel system. Switching to using LNG as a ship fuel will mean a vessel will comply with restrictions on the use of high-sulphur fuels.

"The GASA approval issued by DNV GL is very important for us, as it shows that the new solution can be ordered and retrofitted today," said Philippe Berterottiere, chairman and CEO of GTT. "It will allow interested shipowners to get ahead of the IMO's 2020 global sulphur cap regulations, giving customers and charterers greater certainty as we head to this significant regulatory change. By bringing this solution to market, GTT reaffirms its position as an innovative provider for the industry, continually working to optimize our customers' operational performance."

Hans-Jurgen Voigt, shareholder and managing director of Technolog, remarked: "This advanced technology is a milestone for cost-effective LNG retrofit and newbuilding solutions for larger vessels. With [the] introduction of LNG as ship fuel, there are immediate benefits to ship owners related to a reduced carbon dioxide footprint (EEDI) as well as all other harmful exhaust emissions."

Knut Orbeck-Nilssen, CEO DNV GL - Maritime, said: "This innovative new solution offers forward-thinking shipowners another option when they are considering LNG as a ship fuel and will help to continue the development of this important technology. We look forward to building on this excellent cooperation with GTT and Technolog in the future."

A General Approval for Ship Application (GASA) is a full approval of the technology under consideration, according to the DNV GL Rules for Classification, which examines a typical installation of the technology in a vessel.