LNT Marine: ‘we are ready to disrupt the LNG containment system market’

Since the 1970s, the market for LNG containment systems has been dominated by membrane technology. LNT Marine says its alternative containment system, LNT A-BOX, is ready to dominate what its architects call ’the membrane monopoly’.

LNT Marine’s LNT A-BOX uses independent self-supporting prismatic IMO type A tanks made of aluminium. Its benefits include flexibility similar to Moss spherical tanks in terms of filling levels, as there are no liquid motion (sloshing) issues, and at the same time, better volume utilisation than membrane tanks, according to the company’s chief operating officer Stein Foss. The self-supporting tank enables use of low-density foam materials in the insulation, which with the design criteria applied for ultra-low LNG temperatures, provide "optimal insulation thickness and density for the lowest possible thermal conductivity and boil-off rate," he says.

Mr Foss points out prismatic IMO type A tanks have been used for decades in LPG shipping without problems from liquid motion, nor leakage issues, which he says proves their suitability for LNG with a lower density. "We have recently completed a thorough technical assessment and robustness analysis in close collaboration with the leading ship design company SDARI, and the classification society ABS. This includes detailed FE analysis and fatigue assessment, and confirms that our LNT A-BOX system is a proven, ready-for-market design.

“While we do not yet have a confirmed order for larger-sized LNG carriers, the first vessel equipped with our containment system – 45,000-m³ LNG Jia Xing, originally Saga Dawn – has been trading actively in southeast Asia since early 2020. The LNT A-BOX system has performed very well during operations, including cooling, loading, unloading, ship-to-ship transfer operations and also sailing with varying filling levels.

Saga Dawn was built at China Merchants Heavy Industry’s Jiangsu yard, a facility new to LNG carrier construction, which confirms LNT’s target of lowering barriers for new yards entering LNG carrier construction.

"We viewed the Saga Dawn project as a pioneering project – a prototype to learn from," says Mr Foss "and we’ve already identified improvements to the thermal insulation system and installation process that will reduce costs and time." Vice president of cryogenic insulation at LNT Marine Per Ivar Nikolaisen agrees and says lessons learned will increase the speed of future installations, as will the straightforward design which enables installation by regular shipyard workers without specialised equipment. He calculates these factors "could reduce overall ship production time versus membrane systems."