GTT

GTT (Gaztransport & Technigaz) is a French engineering company headquartered in Saint-Rémy-lès-Chevreuse that designs membrane containment systems for the shipping and storage of liquefied gases. It does not build tanks itself but licenses its technologies to shipyards, mainly in Korea and China, and provides engineering, consulting and support services.

GTT's membrane families are Mark III (with Mark III Flex and Flex+ variants), NO96 (including GW, L03, L03+ and Super+) and the newer GTT NEXT1. They dominate containment on large LNG carriers, and the same technology is applied to LNG fuel tanks. GTT's LNG-as-fuel solutions cover container ships, cruise ships, tankers, bulkers and bunker vessels, with tank volumes from about 1,000 m3 for passenger ships to nearly 20,000 m3 for the largest container ships, and ammonia compatibility has been assessed with class.

The group also runs a digital and performance-monitoring business under GTT Marine and offers 24/7 emergency support (HEARS). Recent news includes an order from Hudong-Zhonghua for an 18,700 m3 LNG carrier tank design and new LNG fuel solutions presented at Gastech 2026.