Tuzla, Turkiye | January 07, 2026 – The future of sustainable bunkering in Northern Europe took a significant step forward as RMK Marine hosted the official steel cutting ceremony for the FLEXI LNG 7800 M3 – HYBRID project.
The vessel, which will be named Celsius, is being developed as a joint venture between Swedish shipping company Sirius Shipping and Nordic energy expert Gasum Group. Scheduled for delivery in the summer of 2027, the project marks a major milestone in the expansion of low-emission maritime infrastructure.
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Specialized Design for “Cool-Down” Services
The Celsius is designed to be far more than a standard bunker tanker. Its configuration includes a massive 27.7 MW Gas Combustion Unit (GCU), a unique addition that enables the vessel to provide specialized cool-down and gassing-up services.
This functionality is particularly critical for LNG carriers and LNG-powered vessels returning from dry dock or those requiring precise tank temperature regulation. While traditional bunker vessels focus almost exclusively on fuel transfer, Celsius acts as a mobile service hub, ensuring that methane slip is eliminated during these technical operations, thereby enhancing environmental safety.
Celsius LNG Bunker Vessel Key Technical Specifications
- Capacity: 7,800 m³ (Capable of carrying both LNG and Bio-LNG)
- Dimensions: 112.9 meters in length and 19.0 meters in beam
- Propulsion: Advanced Hybrid Battery System utilized for peak shaving and safety backup
- Ice Class: 1A rating, specifically optimized for the harsh conditions of Northern European waters
- Environmental Impact: High-efficiency design with an estimated EEDI (Energy Efficiency Design Index) 51% below the 2025 Phase III requirements
Leadership Perspectives: Safety, Innovation and Sustainability
During the ceremony, Jonas Backman, CEO of Sirius Shipping, emphasized the long-standing relationship with the Tuzla-based shipyard:
“It has been 20 years since we built ships here in Tuzla Bay, and we are happy to be back. Safety always comes first, we cannot fix a person’s life, but a sheet of metal or some technical equipment can always be fixed. Let’s have a professional relationship and two great years together.“
Dr. Utku Alanç, CEO of RMK Marine, highlighted the shipyard’s commitment to the energy transition:
“At RMK Marine, innovation goes hand in hand with responsibility. The adoption of alternative fuels reflects our commitment to shaping a cleaner future. This project sets new benchmarks for sustainable shipping and solutions that protect our oceans for generations to come.”
RMK Marine: Pioneers of Turkish Shipbuilding
Located in Tuzla, Istanbul, RMK Marine is one of Türkiye’s most technologically advanced shipyards. As a member of the Koç Group, the country’s largest private conglomerate, the yard has been delivering global maritime solutions since 1997.
- Sophisticated Specialization: RMK Marine is renowned for its diverse portfolio, which spans high-tech naval platforms, sophisticated commercial tankers, and award-winning superyachts. It is the only private shipyard in Türkiye to hold the AQAP 2110 Industrial Quality Assurance certification.
- Innovation & Green Propulsion: The shipyard is a pioneer in alternative energy solutions. Recent projects include the construction of hybrid-electric vessels, dual-fuel powered ships, and innovative sailing Ro-Ro vessels like the Neoliner Origin, which features automated wing sails.
- Infrastructure Excellence: Spanning over 95,000 m², the yard features a 170m slipway and a 200m outfitting quay, allowing for the construction of vessels up to 28,000 DWT. Their commitment to “Safety First” and “Environmental Sensitivity” aligns perfectly with the high-stakes requirements of the LNG bunkering sector.
Gasum: Leading the Nordic Energy Transition
Gasum is a Finnish state-owned energy expert and a primary driver of the Nordic transition to cleaner fuel solutions. As the region’s largest producer of biogas, Gasum provides an end-to-end value chain that serves the industrial, maritime, and road transport sectors.
- Renewable Energy Goals: Gasum has set a bold target to bring 7 TWh of renewable gas to the market annually by 2027. This initiative is expected to achieve a cumulative CO₂ reduction of 1.8 million tons for its customers.
- Maritime Bunkering Leadership: Gasum operates an extensive network of LNG/LBG terminals across Finland, Sweden, and Norway. By integrating Bio-LNG (LBG) into its supply, Gasum enables shipowners to comply with strict regulations like FuelEU Maritime while reducing lifecycle emissions by up to 90%.
- Circular Economy Focus: Beyond fuel supply, Gasum operates 19 biogas plants, converting municipal and agricultural waste into renewable energy and organic fertilizers, reinforcing its role as a circular economy leader.
Sirius Shipping: A Legacy of Maritime Excellence
Founded by the Backman family on the island of Donsö, a historic hub in Gothenburg’s southern archipelago, Sirius Shipping is a cornerstone of Northern European tanker operations. With a culture rooted in safety and close cooperation between sea and land, Sirius has built an elite reputation for transporting oil products, biofuels, chemicals, and LNG.
- Current Fleet Operations: Sirius currently operates a versatile fleet of 11 product/chemical tankers and 2 LNG tankers, with an additional 3 product/chemical tankers under commercial management.
- Strategic Fleet Renewal: The company is currently executing an ambitious growth strategy with 7 newbuildings in progress across various segments. This includes the “Evolution 8K” series, chemical tankers featuring hybrid battery systems and shore-power capabilities designed to exceed 2025 EEDI Phase III requirements by 40%.
- The “Sirius Standard”: Every vessel is designed with a focus on crew well-being and environmental safety, ensuring that high-specification equipment and “Take Me Home” functionalities are standard across the fleet.
Source: Sirius Shipping