Clipper Ships Return: Green Vessels for Shipping Are in the Works
Rolls-Royce Holdings is best known for producing engines that powered planes from the late Concorde to the current Airbus superjumbo. Now the British propulsion giant is working with partners to develop a modern-day clipper ship, as it bets that regulations curbing air pollution emissions will increase fuel costs for conventional ocean freighters and herald a New Age of Sail.
Cargo vessels are set for a design change embracing sleeker hulls and hybrid propulsion systems, according to London-based Rolls, which is helping to develop a ship featuring a 180-foot sail augmented by biomethane engines and carrying 4,500 tons of freight. “We’re at the dawn of a transition,” says Oskar Levander, vice president for innovation at Rolls’s marine unit, who predicts a switch to alternative fuels such as dimethyl ether and liquid natural gas, as well as “high-tech wind.”
Spurring the push are International Maritime Organization (IMO) sulfur caps that already require ship owners to switch to cleaner—and pricier—grades of fuel. Trimmer designs and innovative power systems could more than offset that extra cost, according to Diane Gilpin, project leader at Rolls partner B9 Shipping in Larne, Northern Ireland. Results of wind tunnel and towing tank tests of the B9 design at Britain’s Southampton University were evaluated against data from the Met Office, Britain’s state weather forecaster, simulating 105,000 voyages over a 12-year period. The analysis showed an estimated fuel consumption for the wind-assisted vessel of 46 percent to 55 percent less than an equivalent conventional ship on the same route.
The B9 vessel will measure 330 feet long and derive primary power from a sail hoisted with an automated rig. Rolls will provide a backup power plant that’s able to burn methane produced from municipal waste by another unit of B9 Energy Group. The sail and engine could also be used together for optimal efficiency. A B9 analysis estimates that about 60 percent of the ship’s thrust will come from conventional soft-sails, and 40 percent from the biomethane engine during calm conditions or when it’s maneuvering in port.
Around 90 percent of the world’s cargo fleet is currently propelled by bunker fuel. While it’s relatively cheap at about $600 per ton, it’s also one of the heaviest and dirtiest of crude oil distillates, with a 3.5 percent sulfur content contributing to about 84,000 deaths a year worldwide from marine emissions, according to a 2007 study led by James Corbett, a professor at the School of Marine Science and Policy at the University of Delaware.
Under the IMO rules, ships entering so-called Emission Control Areas covering the English Channel, North and Baltic Seas, and most of the U.S. coast were required to reduce to 1 percent sulfur fuel in 2010, from an already stringent 1.5 percent limit. Ships in the same areas must move to 0.1 percent fuel by Jan. 1, 2015, and all oceangoing vessels will have to adopt 0.5 percent sulfur by about 2020. That will prompt a switch to “a much more diverse fuel pallet,” says Levander.
While the wind-methane hybrid design increases capital costs, B9 says the investment will pay off within three to five years of a ship’s three-decade life-span. “Operational budgets are trumping build costs at the moment,” says Gilpin, adding that B9 is trying to raise the $22 million needed to put a ship in the water within two years. To woo potential buyers, it’s offering to package boat orders with guaranteed-price contracts for biofuel sold by a sister B9 unit.
Sail last dominated freight hauling during the clipper ship era of the mid-1800s, when vessels averaging 30 kilometers an hour (19 mph) and a capacity of 1,500 tons transported high-value goods such as tea, spices, and opium on Asian routes. They also carried tens of thousands of people to the California and Australia gold rushes.
Historic British and U.S. vessels such as the Cutty Sark and Rainbow easily outpaced their steam rivals, and hybrid wind-steam ships were also popular until the 1869 opening of the Suez Canal. The 120-mile waterway linking the Mediterranean and Red Seas allowed travel between Europe and Asia without sailing around Africa. But because the canal basically cut through Egyptian desert, there were no reliable prevailing winds along the route—giving coal-powered vessels an edge.
Sail held on in the form of windjammers, which were slower than clippers but carried loads of as much as 7,800 tons, in the case of Germany’s Preussen. The ships operated on low-value freight routes until as recently as World War II, especially to ports lacking the coal and water required by steam models.
Efforts to introduce vessels powered by liquid gas are more advanced than the modern wind-based experiments. Norway’s Nor Lines, which serves dozens of local ports and a handful of others in the North Sea and Baltic regions, has ordered two ships for delivery next year with LNG engines also built by Rolls-Royce, Chief Executive Officer Toralf Ekrheim said in an e-mail. The company, which already has switched much of its 16-vessel cargo fleet to low-sulfur marine oil, has options to take two more of the ships. The vessels will entirely eliminate soot and cut output of carbon dioxide by 35 percent and nitrogen oxide by 95 percent, according to their Chinese manufacturer, Tsuji Heavy Industries. The model is an offshoot of Rolls’s Environship concept, which includes new bow designs and an integrated rudder and propeller that the company says could boost efficiency by 8 percent.
Still, demand for greener craft has been hurt due to slack growth in the global freight market since the credit crunch and excess capacity as ships ordered during the boom years continue to launch. And freight lines are updating existing ships. A.P. Moeller-Maersk, which controls 15 percent of the container market, is working with MAN’s ship engine unit to reduce the energy consumption of 500 existing craft by as much as 20 percent. The project, backed by Danish state funding, could deliver gains of at least 10 million kroner ($1.7 million) per vessel, the company said in May.
Such savings from existing ships could slow adoption of wind-powered vessels. “The big challenge for the ship owners is the multiplicity of options,” says Nick Brown, a spokesman for marine consultants Lloyd’s Register Group. “People are probably putting off decision-making as long as they can.”