On May 22, the naming ceremony of MV Coralius was performed by Johanna Lamminen, Chair of the Board of Skangas and Chief Executive Officer of Gasum. Being the first European built LNG bunker and distribution vessel, Coralius was commissioned for build at Bodewes Shipyards by Sirius Veder Gas AB.

The company, a joint venture for the majority owned Anthony Veder Group – with a minority share held by Sirius Rederi -, will operate this combined LNG bunker/feeder vessel for Skangas, under a long-term charter.

The initial design for the 1A Ice Classed Gas Carrier was first developed in 2013, but the contract for construction was only signed in 2015 after the joint venture between Anthony Veder and Sirius was established.

FKAB of Sweden initially designed Coralius for a high level of operational flexibility for bunkering ship-to ship (STS), and trading as traditional liquefied natural gas (LNG) feeder. Royal Bodewes and Groot Ship Design, subcontracted by Bodewes, performed the further design review and development.

This latest addition to the fleet will offer LNG bunkering services for Skangas – operating mainly in the North Sea, the Skagerak area and the Baltic Sea.

Dutch influence on fuelling

Since 2010, Skangas, a subsidiary of Gasum, has expanded its LNG transport capacity at sea by entering long-term time charter contracts with Anthony Veder for LNG carriers, Coral Energy, and Coral Anthelia. The addition of Coralius allows for distribution of LNG to a sector that has a clear need and drive to move to sustainable energy but does not have access to natural gas via the pipeline of a shore-based terminal. She will load LNG in Norway and Sweden, for distribution in the Baltic area, with a focus on the Skagerrak and Kattegat area.

As stated, Sirius Veder Gas AB ordered the 5,800 cbm LNG bunker and feeder vessel – the first to be built in Europe – at the Dutch shipyard of Bodewes. The Anthony Veder Group is a key participant in this initiative and, as such, has a major commitment to all segments of gas shipping – from CO2 to ethylene, and from LPG to LNG. Additionally, the group provides comprehensive and efficient technical and commercial ship management services to third parties. Anthony Veder operates a fleet of 30 gas tankers, including five gas tankers that use LNG as fuel.

“We have a long track record in small to mid-size LNG shipping. Last year, we conducted the first safe bunkering operation in the Gothenburg area, for Skangas, with Coral Energy, another of our LNG carriers. The Coralius is our first LNG bunker vessel developed in co-operation with Sirius Shipping, and we are very proud to serve the market, in a safe and efficient way, with the delivery of this dedicated LNG bunker vessel,” Jan Valkier, Chief Executive Officer of Anthony Veder, said.

The new vessel incorporates technology applied in Anthony Veder’s small-scale LNG carriers, including a dual-fuel engine. Both Anthony Veder, and Sirius Rederi, have developed the specific design features required to perform safe and reliable bunkering operations, for example thrusters, to facilitate increased maneuverability.

“I am very happy to see the development of Coralius becoming reality, as a result of our close co-operation with Skangas and Anthony Veder. The synergy between the partners, and the addition of this ship, considerably strengthens our joint position in the local market, and we are excited by the combined knowledge that comes together in this project,” Jonas Backman, Chief Executive Officer of Sirius Shipping, added.

“The intention of Royal Bodewes in starting this LNG project,” as Herman Bodewes recalls, “was to develop a universal ‘Fuel Performance’ operating system for our customers. This would lower the threshold for other shipping companies to embrace LNG as alternative fuel.”

Although FKAB of Sweden developed the initial design, the Dutch company, Groot Ship Design of Leek, slightly refined and tweaked the design in collaboration with Bodewes after the stability was determined.

Jan Willem Cuperus, Managing Director of Groot Ship Design is especially proud of the FEM calculations in combination with the thermal calculations for the spaces in which the LNG tanks are accommodated. The thermal calculations have been performed in cooperation with Flowmotion, of Delft in The Netherlands. The comprehensive package of calculations and engineering led to determining what strength was needed, and what type of steel was to be used. The Royal Bodewes LNG team, however, kept the overall control in the engineering route, inspected and improved the constructions, plus addressed the complete ‘dressing’ of the ship. In cooperation with the various subcontractors, the team has brought together all systems to equip everything according to the requirements.

Gas logistics

Coralius is built according to the guidelines set by the Society for Gas and Marine Fuel (SGMF), which aims to harmonise safe and responsible operations of gas-fuelled ships. Compared to other marine fuels, LNG considerably cuts both sulphur oxide (SOx) and nitrogen oxide (NOx) emissions, and is recognised by the shipping industry as the most viable alternative fuel for the reduction of emissions.

The development of this vessel is part of Joint Industry Project ‘FLEXI’, which is initiated by ‘PILOT LNG’, a collaboration platform within Zero Vision Tool (ZVT). ZVT envisages that increased transport by sea can contribute to enhanced economic growth and welfare, whilst at the same time reducing energy consumption, accidents, and negative environmental impact.

As the combined LNG feeder and bunker vessel is considered an important part of the establishment of an LNG infrastructure, in the Skagerrak/Kattegat area and the Baltic Sea, this project is co-funded by the EU through the TEN-T program. Trans-European Transport Networks (TEN-T) is a European research project tasked to develop LNG projects in European short sea shipping.

Related to the innovative aspects of this project, Royal Bodewes received a subsidy from Samenwerkingsverband Noord-Nederland = Collaboration North-Netherlands (SNN) and the European Union. Facing pressure for more stringent engine and fuel quality standards, demanding major emission reductions to improve air quality and mitigate climate change impacts, the Dutch governments highly support and encourage the application of LNG as an alternative fuel. Given significant first-mover disadvantages, Bodewes’ Coralius was awarded a subsidy to offset some of the cost of converting regular diesel-fueled engines to dual fuel engines and/or developing LNG operating systems in the context of promoting greater use of LNG fuel for transportation.

Primarily developed to safely discharge large quantities of LNG to receiving vessels in a short period of time, Coralius is equipped with LNG transfer equipment. The flush work deck is especially engineered for safe side-by-side operations. Moreover, special winches have been installed to enable safe and swift mooring operations. Bunkering LNG ship-to-ship as such increases the accessibility of this marine fuel offshore for the Scandinavian region, and thus provides a valuable add-on to Skangas’ existing bunkering methods, via truck and terminals along the coast.

The LNG is stored on board in two insulated, low-pressure cargo tanks of the bilobe type, classified by IMO as ‘Independent Type C’, with a capacity of 2,550 and 3,250 cubic metres. These ‘Type C’ tanks, with a design pressure of 4.5 bar, are foam insulated without a bottom outlet. For easy discharging, each tank is equipped with two submerged deep well pumps, allowing a discharge capacity of 4x 210 cubic metres per hour, and a Boil-Off Gas compressor.

Over the years, ‘Type C’ tanks have had an excellent safety record in the gas tanker market. Due to the failsafe design, this is the only tank technology, for marine LNG application, which does not require a secondary barrier in order to cope with the risk of LNG leakages. The foam-insulated tanks are shaped in a bilobe configuration, as this was the preferred design to provide enhanced volume efficiency on board Coralius.

The LNG room amidships features a unique system: the Emergency Shut Down (ESD) – a security system custom made to automatically shut down various critical systems on board when gas is detected.

Featuring dual-fuel propulsion

The Wärtsilä 6L34DF dual-fuel main engine, a six-cylinder in-line configuration of 3000 kW, is predominantly fuelled with boil-off gas and regasified LNG from the cargo tanks, reducing fuel cost. Moreover, the technology of this main engine will enable the vessel to combine LNG with other fuels, such as Marine Diesel Oil (MDO), and Marine Gasoil (GO).

It is noteworthy that, in ‘gas mode’, the engine fulfills the International Maritime Organisation’s (IMO) Tier III requirements, without the need for any after-treatment systems. This is especially important given that the ship will operate in Northern European waters, meaning it will spend time in Sulphur Emission Control Areas (SECA), and Emission Control Areas (ECA).

However, before the LNG can be burned in the engine, it has to be evaporated and heated to the correct temperature. The evaporated gas has a fixed pressure depending on the LNG storage tank pressure. The gaseous fuel is transferred from the cargo tanks below deck, to the engine, through double-walled pipes. The inner pipe is fully enclosed within an outer pipe, while the annular space between these two pipes is mechanically ventilated. In case of a gas leakage from the inner pipe, the outer pipe will form a second barrier to contain any leak and prevent gas from entering the engine room. Gas leaking from the inner pipe can be detected with gas detectors in the ventilation pipe before entering the extraction fans. Upon detection, the affected gas supply line can be shut down.

The Wärtsilä main engine features, as standard, a Gas Valve Unit. The main functions of the gas valve unit are to regulate the gas feeding pressure to the engine and to ensure a fast and reliable shut down of the gas supply. The latter requirement is also specified in the IGF code, which states that each item of gas-consuming equipment has to be provided with a set of “double block and bleed” valves. The double block and bleed valves consist of two quick closing valves and a ventilation valve between the quick closing valves. The two block valves provide full redundancy as they are installed in series. Two nitrogen generators, to purge the gas systems and replenish the combusted LNG in the LNG storage tanks, complement the LNG system.

The main engine is coupled to the propeller shaft through a Wärtsilä reduction gearbox, driving a single Controllable Pitch Propeller (CPP). The main propeller shaft/gearbox has a Power Take Off (PTO) to a shaft alternator of 650 kW. The shaft line is suitable for use with environmentally friendly lubricants, and equipped with a Wärtsilä Airguard aft seal that allows zero emissions. The propeller shaft line on the gearbox can optionally be clutched off, enabling the main engine to function as a ‘clean’ LNG generator motor during unloading operations.

Behind the CPP is a free hanging Becker balance rudder, operated by a Roll Royce Rotary Vane steering gear. The 600 kW retractable azimuthing ZF bow thruster, in combination with the 400 kW Verhaar Omega tunnel thruster in the stern, contributes to the improved manoeuvrability. Both thrusters are electrically powered, either by the shaft alternator or one of the generator sets, and controlled through a variable frequency drive unit.

Beside the shaft generator, the auxiliary equipment consists of two Mitsubishi gas generator sets of 375 kWe, and one MAS 760-S diesel generator set of 475 kWe. The emergency, or harbour, generator is a Volvo Penta set. The vessel is also equipped with a 1,000 kW dual fuel boiler, which uses the boil-off gas from the cargo tanks to heat the hot water system.

Marine Service Noord provided the engineering and procurement of equipment for the mechanical systems in the engine room and installed the cargo handling systems on the main deck of the vessel. Alewijnse Marine was responsible for the design, delivery and installation of the electrical and technical automation, as well as the alarm systems on board: This comprises monitoring and control systems (ACMS), the power management system (PMS), main switchboard (MSB), emergency switchboard (ESB), closed circuit TV installation (CCTV), and distribution panels, along with all indoor and outdoor lighting, transformers, frequency drives, harmonic filter units, the shaft generator, plus the stern and bow thruster e-motors.

The vessel is further designed to be as energy efficient as possible with features such as a slender hull, frequency controlled pumps/ fans, and a heat recovery system. These measures not only reduce costs further but will also lower the environmental footprint of the vessel.

Interior design and architecture

The superstructure is located aft and facilitates comfortable accommodation for twelve persons. All cabins are single berth, complete with ventilation, heating, air-conditioning, and outfitted with private sanitary units.

The wheelhouse contains the navigation console, with all the required navigation, communication (according GMDSS A3), and ship control facilities, as well as a dedicated cargo-handling desk. Alphatron delivered the main bridge consoles, including the radio desk, containing a complete range of navigation and communication systems.

The bridge systems are based on complementary components and use a common network to support a comprehensive suite of displays, controls and cargo monitoring systems. All available information can be viewed on any workstation, either in the engine control room, captain’s office, or public spaces of the ship. Company SARC provided the on-board loading computer software, LOCOPIAS.

Although the bridge wings are enclosed, an exterior walkway around the wheelhouse is provided as an outside observation post, and for maintenance purposes.

Directly below the wheelhouse, we find the officers’ cabins and a few crew spaces. The superstructure further accommodates the mess room, a galley with pantry, an office and the emergency generator. The accommodation below deck under the superstructure (in the aft hull) consists of more crew cabins; this section also houses all air-conditioning, switchboard room and engine room workshop, as well as provision storage, a changing room and other technical spaces or storages. Each cabin is fully equipped with the latest audio-visual equipment, whilst a sauna and fitness room, with adjacent shower, provide relaxation after a hard day’s work.

Esme Marine, of Veendam, fulfilled the carpentry work and finish of all wheelhouse and accommodation furniture, whilst Huizing Scheepsstoffering, of Hoogezand, supplied the soft furnishings.

All hands on deck

Apart from the cargo hose/fender handling cranes, and LNG pipes, the main deck is flush between the forward bulkhead of the superstructure and forecastle deck, with an interruption amidships where the compressors and cargo-handling units are accommodated.

The aft main deck, behind the superstructure, is home to the aft mooring equipment, including two mooring winches. At the stern, on centreline, slightly raised above main deck, is the Hatecke freefall lifeboat in its dedicated launch and recovery system. To port side of the superstructure is the ManOverboard-Boat (MOB)/Fast Recue Boat (FRB), with its own slewing crane, whilst on both sides, at the same level, the two life rafts are to be found on the open deck. MOB and life raft crane are delivery Global Davit, while the MOB/FRB are delivery Hatecke, and the life rafts are from Survitec.

Furthermore, for enhanced STS bunkering, two more mooring winches are placed more amidships on main deck: one in front of superstructure and another just aft of the sheltered forecastle deck. The anchoring and forward mooring equipment is on the sheltered forecastle deck, including two anchor winches, one mooring winch.

Fairleads en bollards are in accordance with OCIMF and Optimoor calculations. All mooring equipment, winches, anchors and chains, are supplied by C-Nautical from Sappemeer.

Next generation LNG bunkering

Situated along the Winschoterdiep, in Hoogezand, The Netherlands, Bodewes Shipyards BV is a member of the Royal Bodewes Group. The shipyard, founded in 1812, focuses on designing and building ships according to market demands. On November 30, 2012, Bodewes was awarded with the predicate, ‘Royal’.

Despite the continued challenging times in the Dutch shipbuilding industry, Bodewes Shipyards’ ethic is to invest significantly in the development of its vessels. Its philosophy, unlike a lot of other shipyards, is that the market dictates the configuration of ships, not vice versa. Consequently, a changing market requires evolving designs to keep pace with the changes. With the development of Coralius, Bodewes succeeded in fulfilling this business vision.

This ultra-modern vessel features a dual-fuel engine and boiler, thrusters that facilitate enhanced close-quarters maneuvering, and ice class notation (1A), which will allow it to trade in the Baltic region during winter. In combination with the hull design of low block coefficient, the emissions will be significantly lower than that of traditional vessels, as the ship will primarily run on LNG derived from the cargo.

Coralius is owned by Sirius Veder Gas AB, a joint venture where Anthony Veder possesses the majority of shares. Another Dutch success story… A new LNG era has arrived.

Tom Oomkens

This article was previously published in Maritime Holland edition #4– 2017.