Hydrogen tankers: from first mover to full fleet

While deep-sea hydrogen transport is drawing much of the current attention, hydrogen is also gaining traction in the inland and short-sea vessel segment. In Lithuania, the country’s first hydrogen-powered inland waterway vessel was launched in 2024 by Western Baltija Shipbuilding. Designed for the Klaipėda region’s rivers and lakes, the vessel is equipped with a 60 kW hydrogen fuel cell and lithium-ion battery hybrid power system. Though its output is modest, the vessel’s operational profile reflects growing interest in hydrogen as a marine fuel, even in non-industrial contexts.

Nevertheless, hydrogen propulsion for ocean-going tankers remains at an earlier stage. Hyundai’s HiMSEN four-stroke LNG–hydrogen dual-fuel engine has been proposed as one potential solution. The engine has been designed for medium-speed marine applications and is currently undergoing combustion tests with hydrogen blends of up to 50%. The manufacturer reports that early results indicate hydrogen’s high flame speed may allow for increased thermal efficiency and improved transient response, provided combustion stability and pre-ignition are carefully controlled.

“Without carrier-specific infrastructure, direct LH2 imports remain infeasible, regardless of vessel availability”

Further development is ongoing to improve hydrogen injection systems and address material compatibility, particularly in relation to embrittlement risks. The engine’s designers also note that fuel supply chain stability will be critical, particularly in terms of hydrogen purity and pressure regulation.

However, propulsion is only one part of a broader chain. Bunkering logistics, onboard safety systems, and crew training all require substantial revision. LH2’s high diffusivity and low ignition energy demand multiple layers of containment and constant leak detection. Most proposed LH2 tanker designs now include dual-walled tanks, vacuum insulation, and distributed gas sensors linked to automated venting systems. Regulatory standards for LH2 bunkering have not yet been harmonised globally, which adds complexity to ship design and port readiness.

Hydrogen’s risks are not confined to technical aspects. The economics of LH2 transport remain sensitive to energy prices, liquefaction costs, and boil-off losses. For example, liquefaction of hydrogen consumes approximately 30% of its initial energy content. Until scale is reached, few shipping companies are likely to make unilateral investments in hydrogen carriers.

In Oman, however, public and private sector alignment appears more advanced. Speaking in April 2025, Hydrom chief executive, Salim Al Harthy, told the Oman Observer that the country intends to become “a global hub for green hydrogen”, with maritime exports forming a core part of the strategy. He stated that liquefaction, port storage and shipping must be integrated into project planning from the outset, given the cost of retrofitting hydrogen-specific infrastructure at a later stage. “Shipping must not be an afterthought,” he said. “It is the bridge that connects Oman’s production capacity to industrial demand in Europe.”

The timeline remains tight. Final investment decisions for Oman’s first hydrogen export modules are expected by 2026, with carrier deliveries required by the end of the decade to meet European import targets. Newbuild availability, classification society approval, containment system reliability and engine certification will all play critical roles. Regulatory frameworks must also keep pace with technology, particularly around safety and port reception standards.

Until then, Suiso Frontier remains alone. But the vessel’s legacy may yet lie in demonstrating not just what is possible, but what must follow.