GTT North America (GTTNA), the US subsidiary of French engineering and technology company GTT (Gaztransport & Technigaz SA), has received ABS approval in principle for the design of a 2200 m3 LNG bunker barge. The design will incorporate GTT’s proven membrane cargo containment system (CCS), which is utilised in approximately 70% of the global LNG carrier fleet and nearly 90% of LNG carrier projects on order.
GTT developed the membrane LNG bunker barge to demonstrate the efficient storage of LNG and safe, reliable management of boil-off gas (BOG) in an unmanned push barge application. The barge was designed for use in bunkering operations including ship-to-ship LNG transfers or LNG bulk transport in US inland waterways, harbours, and intra-coastal service. The barge could also operate as a mobile refueling resource or be moored temporarily to serve as a refueling station.
ABS Director of US Gas Solutions, Roy Bleiberg, said that bunkering infrastructure that can meet various operational needs of vessels was an important part of the large scale adoption of LNG as a marine fuel. “The use of the LNG bunker barge will be a critical part of infrastructure development and this design, which leverages proven GTT technology, is certainly a concept that LNG stakeholders should consider.”
Cargo containment system
The CCS selected for the barge was GTT’s proprietary Mark III Flex system, an enhancement of the Mark III system that allows for improved thermal and structural performance of the CCS. The Mark III membrane CCS consists of a cryogenic liner directly supported by the vessel’s inner hull, which allows for maximum volumetric utilisation of the available cargo space. This liner is composed of a primary metallic membrane fastened atop a prefabricated insulation panel that includes a complete secondary membrane.
The GTT membrane LNG bunker barge will be capable of loading 2156 m3 (570 000 US gal.) within 4.5 hours and towed at maximum speed of 8 knots in an efficient footprint: 64.2 m (212 ft) overall length, 14.8 m (48.5 ft) breadth, 7.2 m (15.7 ft) depth, and 2.6 m (8.5 ft) fully loaded design draft. The dimensions and gross tonnage of approximately 1440 GT afford the GTT membrane LNG bunker barge greater maneuverability and access throughout inland and intra-coastal waterways.
A distinguishing feature of the GTT membrane LNG bunker barge is the management of natural BOG through small scale reliquefaction units. The StirLNG-4 cryo-cooler unit from the Netherlands-based Stirling Cryogenics was the basis of the boil off management system design.
Allyn Risley, Chairman, GTT North America, said: “This barge design, now approved in principle by ABS, provides a robust solution for boil off gas management, an essential requirement for any atmospheric LNG storage system. The design is a major step forward in bringing the coldest cargo with the highest stored energy value to the US LNG fuel market in a safe manner.”
Alameda, CA-based Herbert Engineering Corp. (HEC) was commissioned to develop the hull and preliminary machinery design scope and Houston-based CH-IV International to develop the cargo handling system (CHS) design scope.
ABS Consulting also assisted in the development of the GTT membrane LNG bunker barge project.
Adapted from press release by Ted Monroe
Read the article online at: https://www.lngindustry.com/small-scale-lng/28032014/lng_bunker_barge_approved_in_principle_by_abs/