TEN-OH: Japan’s First Hydrogen Dual-Fuel Tugboat Begins Demonstration Operations

Japan continues to demonstrate its commitment to maritime decarbonisation with substance over hype. The TEN-OH isn’t just another concept vessel—it’s a fully operational, high-power tugboat now entering commercial demonstration. What makes this particularly noteworthy is the technology partnership: Belgian expertise from CMB.TECH combined with Japanese shipbuilding precision. This is exactly the kind of international collaboration the hydrogen transition requires.

Japan’s first hydrogen dual-fuel tugboat, TEN-OH, has begun demonstration operations following its delivery by Tsuneishi Shipbuilding in October 2025. The 38-meter vessel represents a significant milestone in Japan’s Zero Emission Ships Project and marks the second deployment of BeHydro’s hydrogen combustion technology in a commercial tugboat—following the successful Hydrotug 1 at the Port of Antwerp-Bruges.

The vessel is now conducting demonstration voyages and bunkering operations, with trials scheduled to continue through 2026.

Technical Specifications

Specification	Value
Vessel Name	TEN-OH
Length Overall	38.0 m
Breadth	9.6 m
Draft	4.2 m
Gross Tonnage	<300 GT
Main Engines	Twin BeHydro 12-cylinder hydrogen dual-fuel ICE
Power Output	4,400 hp class (~3.3 MW total)
Hydrogen Storage	~250 kg (high-pressure compressed)
Fuel Type	Hydrogen + traditional marine fuels [CH2]
CO₂ Reduction	~60% vs. conventional tugboats
Classification	ClassNK

Why Hydrogen Tugboats Matter

Tugboats are deceptively important vessels for maritime decarbonisation. They operate in ports—areas increasingly under scrutiny for air quality and emissions—and require substantial power for manoeuvring large vessels. A typical harbour tug runs its engines at high loads for extended periods, making them significant emissions sources despite their modest size.

The challenge for hydrogen tugboats is maintaining the high power output and reliability that port operations demand. TEN-OH addresses this directly with its twin 12-cylinder engines delivering 4,400 horsepower—matching conventional tug performance while significantly reducing emissions.

International Technology Partnership

TEN-OH’s propulsion system comes from JPNH2YDRO, a joint venture between Tsuneishi Group and CMB.TECH. The BeHydro engines are manufactured by a joint venture between Anglo Belgian Corporation (ABC) and CMB.TECH—the same partnership that delivered engines for Hydrotug 1.

Key Technology Partners

• Shipbuilder: Tsuneishi Shipbuilding (Fukuyama, Japan)
• Hydrogen Systems: JPNH2YDRO (Tsuneishi Group + CMB.TECH)
• Engines: BeHydro (ABC + CMB.TECH)
• Classification: ClassNK
• Steel: JGreeX green steel by JFE Steel Corporation

The use of JGreeX green steel throughout the vessel’s construction adds another layer of sustainability—reducing the embodied carbon of the vessel itself, not just operational emissions.

Context: The Growing Hydrogen Tug Fleet

TEN-OH joins a small but growing fleet of hydrogen-powered tugboats worldwide. The most direct comparison is Hydrotug 1, operational at the Port of Antwerp-Bruges since late 2023:

Specification	TEN-OH (Japan)	Hydrotug 1 (Belgium)
Length	38.0 m	30.2 m
Power	~3.3 MW (4,400 hp)	4 MW
H₂ Storage	~250 kg	415 kg
Bollard Pull	Not specified	65 tonnes
Engines	BeHydro 12-cyl dual-fuel	BeHydro V12 dual-fuel
Emission Reduction	~60%	~65%

Both vessels use the same core BeHydro technology, demonstrating that hydrogen dual-fuel combustion is now proven and scalable across different vessel designs and operating environments.

The Nippon Foundation Zero Emission Ships Project

TEN-OH was developed under the Nippon Foundation’s Zero Emission Ships Project, which aims to achieve carbon neutrality in Japan’s coastal shipping sector by 2050. The project is developing and demonstrating several vessel types:

• TEN-OH: Hydrogen dual-fuel tugboat (delivered October 2025)
• Hanaria: Hydrogen fuel cell + biodiesel passenger vessel (completed certification voyages in 2024)
• Hydrogen tankers and cargo vessels: Planned trials through fiscal 2026

Funding & Policy Support

The project benefits from Japan’s substantial commitment to hydrogen technology through the Green Innovation Fund, a ¥2 trillion (~€12.5 billion) programme managed by NEDO (New Energy and Industrial Technology Development Organization). This fund supports the entire hydrogen value chain for shipping:

• Marine hydrogen engine development (Kawasaki, Yanmar, Japan Engine)
• Liquefied hydrogen fuel supply systems
• Vessel construction and demonstration
• Bunkering infrastructure development

Separately, the Japanese Ministry of the Environment and Ministry of Land, Infrastructure, Transport and Tourism have approved Yanmar’s production plan for hydrogen-fuelled engines and fuel cell systems—signalling regulatory support for scaling production.

Project Timeline

• March 2025: TEN-OH launched at Tsuneishi Shipbuilding, Fukuyama
• October 9, 2025: ClassNK classification completed
• October 15, 2025: Delivery to operator
• 2025-2026: Demonstration voyages and bunkering trials
• 2026+: Expected transition to commercial operations

What This Means for the Industry

TEN-OH’s demonstration phase will provide valuable operational data for the broader hydrogen shipping transition. Key questions to watch:

• What hydrogen utilisation rates are achievable in real port operations?
• How does bunkering logistics work for compressed hydrogen in a busy port environment?
• What maintenance and training requirements emerge from commercial operation?
• Can the 60% emission reduction target be consistently achieved?

Tsuneishi Shipbuilding has indicated it will apply the expertise gained from TEN-OH to future vessel projects, including methanol-fuelled and LNG-fuelled ships. The company sees hydrogen as one pathway in a multi-fuel strategy for maritime decarbonisation.

For port operators considering hydrogen tugs, TEN-OH and Hydrotug 1 together demonstrate that the technology works. The remaining questions are about infrastructure, fuel supply, and operational economics—challenges that become clearer only through real-world demonstration.