A voyage of discovery

New technology can make ships more versatile, more efficient and cleaner, too

The Economist  Jul 14th 2012 | ALESUND | http://www.economist.com/node/21558549

IN THE days when Norsemen pillaged their way around the monasteries and villages of Europe, Norwegian shipwrights were at the forefront of naval architecture. They still are. Norway is an important centre of marine innovation and several foreign companies have operations there, too. One such is the marine division of Rolls-Royce, a British firm, which is collaborating with Farstad, a shipping company based in Alesund, and STX OSV, a shipbuilder. The result of their efforts is Far Solitaire (pictured above), the first of a new class of vessels which bristle with novel technology that promises to make shipping safer, cleaner and cheaper.

Far Solitaire has been designed as a platform-supply ship for the North Sea’s oil and gas industry. This means she is not a large vessel. She is 91 metres long (one-third of the length of a typical container ship), has a deadweight of 5,700 tonnes and cost about $70m. But some of the innovations she uses should be applicable to vessels of all sizes.

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At the moment she is being fitted out by STX OSV at its Langsten shipyard on Tomrefjord. In October she will be delivered to Farstad, who will use her to supply rigs in the region’s notoriously heavy seas. Crucially, she has to be able to hold her position while transferring cargoes that include various noxious materials which are employed in drilling or pumped into wells to improve the process of extraction. These have to be delivered to and removed from the platforms. Such transfers are potentially hazardous for the people involved and for the environment.

One of Far Solitaire’s most important innovations is her wave-piercing hull. Below the waterline her bow has the bulbous drag-reducing nose that has become a familiar feature of modern ships. Above it, however, things are all new. Where a standard ship’s bow would have a flat foredeck, Far Solitaire’s flows up and over the vessel. This means that instead of riding the waves, as most ships do, she can penetrate them.

That is a crucial change. When a ship rides the waves her engines slow down and then surge as her hull rises and falls. By piercing the swell, Far Solitaire will be able to maintain her engines at a constant speed. This will cut fuel consumption, reduce wear and tear, and make life for the crew safer and more comfortable.

Future shipshape

Far Solitaire is powered by a conventional diesel-electric system consisting of three engines connected to generators that run electric motors. The thrusters which those electric motors drive, however, are anything but conventional.

The main pair are stern-mounted Azipull propellers. These are similar to the azimuth thrusters already used on some vessels: propellers on pods that can be rotated to push the ship in different directions, making a rudder unnecessary. But the Rolls-Royce Azipull has the propeller at the front of the pod rather than the back. That means the propeller operates in a smoother flow of water, which improves efficiency and assists steering. This design has been made possible using computational fluid dynamics to perfect the shapes of the blades and pods.

Further control is provided by two bow thrusters. These are propellers mounted in transverse tunnels in the hull, to help position the craft and hold her stable while alongside a rig. And there is also an azimuth thruster that can be swung down from the forward part of the hull if an extra push is required.

All of these propulsion systems are handled by moving one of the joysticks next to the captain’s chair in a bridge with a 360° view that looks more suitable for the starshipEnterprise than what is, after all, a souped-up freighter. The consequences of moving the joystick can, fortunately, be practised on shore without risk to ship or platform, courtesy of a new 360° bridge simulator in Rolls-Royce’s marine-training centre in Alesund. The captain can also call on the assistance of an electronic positioning system that uses a combination of data from satellites, gyrocompasses, and wind and motion sensors to operate the thrusters automatically.

Solid freight is carried on a deck that has an area of 1,020 square metres. Liquids, meanwhile, are stored below deck in tanks, each of which is fitted with its own pumping system, in order to avoid the risk of mixing substances best kept separate.

Borge Nakken, who is in charge of technology and development at Farstad, expects Far Solitaire to use about 40% less fuel than a conventional vessel of the same size that is carrying out similar tasks. This is a remarkable saving, and although she is a small, specialist vessel, many of her features, particularly the new bow and the more efficient system of propellers, could help reduce fuel consumption and emission levels in larger ships as well.

Stricter regulations on ships’ emissions are on their way—including, in particular, new controls for vessels in the North Sea and the Baltic, and off the coast of North America. That means shipowners who wish to ply these waters will have to stop using bunker fuel (the cheap stuff left over once petrol, diesel and aviation fuel have been distilled from crude oil) to power their vessels because burning it produces too much sulphur dioxide, nitrogen oxides and soot. That gives extra impetus for technology of the sort being tested in Far Solitaire. And this time no villages will have to be pillaged to pay for it.