BW LNG has ordered the world's first large LNG carriers featuring a three-tank configuration, breaking the four-tank standard used since the 1970s. The contract, confirmed on 15 May 2026 with HD Hyundai Samho, covers two vessels priced at approximately $253 million each, with deliveries scheduled for Q2 and Q3 2029. This order complements a sister pair due in November 2025, bringing the total to four vessels and over $1 billion in committed capital. The three-tank design maintains a total capacity of around 174,000 cbm but reduces the surface-area-to-volume ratio, lowering boil-off rates and methane leakage. The vessels will be powered by WinGD XDF 2.2 engines with variable compression ratio, shaft generators, and full reliquefaction, aiming for high efficiency and CII A ratings through 2030. This naval architecture shift is the most significant since the introduction of the Mark III Flex containment system and may redefine charterer requirements for post-2028 LNG carriers.