Dream Boat: A concept for a renewably powered cargo vessel could help drive emissions-free shipping.
The Irrawaddy dolphin is a strange-looking beast. Round-headed, snub-nosed and a little smaller than a human, the critically endangered marine mammal lives around the coasts and estuaries of the Bay of Bengal, Brunei and Malaysia, and has an endearing habit of helping fishermen out in exchange for some of their catch. But this odd, rare animal is lending its name to an even stranger-looking, but much larger, sea-goer: a zero-emissions, hydrogen-powered concept for a cargo ship designed by Scandinavian shipping company Wallenius Wilhelmsen Logistics (WWL).
The E/S Orcelle (the French name for the Irrawaddy dolphin) is a bold concept to explore ways to reduce the environmental impact of cargo shipping, cutting or even eliminating carbon emissions while also tackling other factors associated with ships that are regularly loaded and unloaded in different ports throughout their lifetime. Even its designation is a nod towards a green agenda E/S stands for ’environmentally sound’. Although WWL stresses that Orcelle is a concept, and will likely never be built in its entirety, it intends to use the components of its design to improve future forms of cargo shipping. ’While futuristic in its concept, we believe the E/S Orcelle represents the achievable goal of building an environmentally friendly cargo ship,’ said WWL chief executive, Nils Dyvik. ’We are determined to be at the forefront, along with the World Wildlife Fund, to help and protect marine life on the high seas.’
“WWL’s E/S Orcelle requires less energy than a conventional ship to push it through the water”
WWL, which operates from Sweden and Norway, is no small-fry shipping company it is one of Europe’s largest movers of cars from country to country, with clients, including Jaguar Land Rover, transporting some 1.7 million vehicles by sea every year. Therefore, Orcelle is visualised as a large ship. Designed to carry 13,000 tons of cargo on eight decks with a total area of 85,000m2, the ship could transport 10,000 cars 50 per cent more than a conventional car carrier. The design challenge is to do this using only renewable resources, and without any need for ballast water.
This is becoming an increasing concern for shipping companies, as ballast is a major source of biological pollution. Conventional ships are designed to be stable when fully laden, so when they are unloaded, ballast tanks need to be filled to ensure the ship sits at the right level in the water. Unloading the ballast water elsewhere in the world introduces any marine organisms that have been sucked into the tanks into a foreign environment, which can lead to trouble for the local ecosystem.
The Orcelle, therefore, combines hull design, propulsion systems, and a variety of energy-harvesting methods to come up with a ship that looks nothing like anything currently in the sea.
For a start, Orcelle is a pentamaran it has five hulls. This is a progression from the WWL design team’s original concept, a streamlined trimaran. Compared with conventional monohull designs, this form provides greater stability, less drag and improved utilisation of energy, the team said.
However, a trimaran isn’t the best shape for a cargo ship because there is limited scope in a three-hull vessel for cargo space. This led to the two outside hulls being shrunk down to outriggers, or sponsons, in the next design stage. Finally, the designers opted to split the sponsons, with two at the bow of the vessel and two at the stern, bracketing a long, slender main hull. The slim sponsons, shaped something like a section of an aircraft wing positioned edge-on pointing downwards into the water, provide extra stability, meaning that the ship will not need ballast water. ’In addition,’ the team said, ’the pentamaran hull design will contribute to the improved utilisation of energy and clean flow of water around the vessel.’
“We believe the E/S Orcelle represents the achievable goal of an eco-friendly cargo ship”
NILS DYVIK, WWL
The hulls are made from aluminium and thermoplastic composites, rather than carbon steel, as they are lighter, more fatigue-resistant, easier to shape, more recyclable and require less maintenance. The lighter weight, combined with the hull shape, means that the Orcelle requires less energy than a conventional ship to push it through the water. This low energy requirement is crucial if the ship is to gather all of its motive power from renewable sources. ’We have observed various emerging technologies that enable smaller ships to utilise energy from renewable sources,’ the company said. ’We are keeping a close watch on emerging trends and are hopeful that these solutions may become applicable to larger vessels in the future.’
One source of energy would come as no surprise to any pre-20th century sailor the wind. Orcelle has three rigid sails, each with an area of 1,400m2 and made from composite material, which can be rotated and positioned to catch the wind. Moreover, these sails would each incorporate 800m2 of photovoltaic panels to generate a maximum of 2,500kW of solar electricity; when not used for propulsion, the sails would be folded back against the upper deck of the ship to maximise the amount of solar energy they receive.
More electricity-generating components are located underneath the ship. Joining the sponsons to the keel of the main hull are 12 horizontal fins, three on each sponson. These are configured to move up and down as the ship moves through the water, with the movement converted into electricity by hydraulic motors.
The solar and wave energy is planned to be stored in the form of hydrogen, obtained by electrolytic splitting of seawater; this, WWL concedes, will require the development of new technologies. The hydrogen would be converted back to electricity in on-board fuel cells with a total output of 10,000kW; these, the design team said, would provide about half of the energy used to actually propel the ship.
As well as the composite sails, Orcelle makes its way through the water using variable-speed electric propulsion systems, known as pods. The vessel would carry two pods, one at either end of the main hull and each incorporating a motor, gearbox and propellor. Pod systems already well established on large ships and produced by companies such as Rolls-Royce, which is providing pods for the Queen Elizabeth-class aircraft carriers currently under construction can turn through 360°, making them an integral part of the ship’s manoeuvring systems. The other components of these two rudders at the stern of the ship are also operated by electrical and hydraulic energy.
Other energy-consuming systems would be a propulsion system operating through flapping the keel-mounted fins when they are not being moved by waves, along with shipboard utilities such as lighting, ventilation, control, navigation and equipment operation. These will run off the electricity generated by the ship, while other systems, such as the raising and lowering of the stern ramp and adjusting the height of the cargo decks to accommodate different types of vehicles, would use hydraulic power.
Conceptual work began on the Orcelle in 2004, with the ship first presented a year later. Since then, WWL has kept working on the project, bringing in new designers and technologies via ’Orcelle grants’, which now also includes concepts for an emissions-free cargo terminal. It envisages an in-service date for an Orcelle-like ship around 2025.
the data – cargo concept
The E/S Orcelle looks nothing like anything currently in the seaLength: 250m
Total height with sails erected: 95m
Design speed (max): 20 knots
Design speed (service): 15 knots
Lightweight: 21,000 tonnes
Maximum deadweight capacity: 13,000 tonnes
Pod propulsion: 2 x 4,000kW
Sails: 3 x 1,400m2
Fins: 12 x 210m2
Eight decks, three with adjustable height