French naval engineering firm Gaztransport & Technigaz (GTT) has secured two approvals in principle (AiP), one from DNV and one from Bureau Veritas (BV), for its three-tank liquefied natural gas (LNG) tanker design.

The AiPs were issued for the Mark III and NO96 technologies developed by GTT.

By suppressing one cofferdam, one pump tower and all associated cryogenic equipment, the new three-tank LNG carrier concept can cut down construction expenses.

Furthermore, to reduce materials costs, the containment system’s overall surface area will be decreased by around 2,000m².

According to the company, the improved ratio between the volume of LNG transported and the surface area of the cryogenic liner will lower the daily boil-off rate.

With the Mark III Flex technology, the firm is expecting a boil-off rate as low as 0.080% of tank volume a day, compared to rates of 0.085% of tank volume a day with the LNG carriers presently in service.

GTT chairman and CEO Philippe Berterottière said: “For almost 60 years, the GTT Group has been constantly improving its technologies to offer its customers solutions that meet their requirements as well as those of the regulatory authorities.

“Thirty years ago, we upgraded LNG carriers from five to four tanks and we now hope to bring the market forward with a three-tank LNG carrier. We hope to see this concept become standard in future years.”

Recently, GTT received an order from South Korea’s Daewoo Shipbuilding & Marine Engineering (DSME) for tank design for ten new LNG carriers.