HD Korea Shipbuilding & Offshore Engineering Co., (HD KSOE) has achieved a breakthrough by obtaining approval in principle (AiP) for its vacuum insulation technology designed for liquefied hydrogen storage tanks. This approval was granted by major international classification societies, signifying a significant advancement in large-scale LH₂ tank insulation design. The vacuum insulation system developed by HD KSOE aims to tackle crucial challenges faced by the maritime industry in using hydrogen, particularly in terms of storage scalability and fuel transportation. The system, similar to thermos flasks, allows for the storage of liquid hydrogen at -253°C while minimizing boil-off gas. The successful testing of a large-scale vacuum chamber for AiP marked a world-first technical validation for this innovative technology. Collaboration with global industry leaders like Woodside Energy, MOL, and Hyundai Glovis has been instrumental in the design development and validation process. LR, one of the classification societies involved, confirmed a notable reduction in vacuum time in shipyards following design assessments and performance verifications. This achievement underscores the commitment of HD KSOE and its partners to drive the energy transition towards net-zero goals and revolutionize hydrogen storage solutions for maritime applications.