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MARINE | Green shipping In association with Hiscox
A new golden age of sail? As the marine team at Hiscox argues the answer to improving the global shipping industry’s carbon footprint could be blowing in the wind Sailing ships plying their trade across the high seas could once again become a familiar sight as the global shipping trade attempts to tackle its carbon emissions in the fight against global warming. With global shipping accounting for around 3% of the world’s greenhouse gas emissions, the shipping industry is looking to reduce its carbon footprint. There is also a financial incentive for shipowners, that are feeling the pinch from rising fuel costs which on average already account for two-thirds of their operating costs. Scientists and engineers are going back to the future by looking again at the ancient technology of sails that have been powering ships since the time of the Ancient Egyptians.
BLAST FROM THE PAST
Today’s sails are not the kind that we would recognise from the Cutty Sark or HMS Victory. Michelin, the French tyre manufacturer, has designed prototype giant inflatable sails that can be hoisted and inflated by pressing a button, while sensors will automatically trim the sails according to the wind speed and direction, rather than needing dozens of sailors to tend them, as in the golden age of sailing ships. The company says it hopes to test the technology on a commercial freighter this year. There are also hard sails which effectively act like upright wings to propel the ship forwards. UK company BAR Technologies has signed a deal with Cargill, the US chemicals giant, to retrofit its 150-foot-high steel sails onto one of its bulk carriers. Then there are rotating sails, which use the Magnus Effect, The Marine Insurer | June 2022
whereby differences in air pressure created around a spinning object are used to push a ship forward. Maersk, the Danish shipping giant, has fitted 30-metre-high spinning cylinders to one of its tankers to test the concept. If successful, it says it could fit them to around half of its fleets. There are also other ideas being worked on by researchers, ranging from rigid sails that suck in air, to kites and wind turbines that would generate both power and propulsion. There’s even an idea to turn ships into sails, by designing hulls that are tall but thin that can be sailed directly into the wind and generate pull to move forwards, just like an airplane. “The future of ship propulsion is hybrid,” Gavin Allwright, Secretary-General of the International Windship Association (IWSA) recently wrote. Retrofitting wind propulsion systems to vessels could deliver savings in fuel consumption of 20% or more, he states. This would represent the equivalent to thousands of tonnes of fuel for the biggest container ships, while also allowing them to sail at the same speeds as before. If sails and other wind systems are integrated into the design of new ships, the savings could be much higher. Apart from helping the shipping industry to cut emissions, wind-propulsion champions point to other benefits of adding sails to ships including reducing the wear and tear on engines and other machinery and increasing the vessels’ stability. They could even allow shipping routes to reopen that were previously thought to be uneconomical.
ALL HOT AIR?
Many of these designs are still only in the prototype stage, but some shipping experts are sceptical. “There’s a decade of (wind propulsion) designs that look good, that save money, that in theory pay for themselves, that haven’t materialised into action,” Tristan Smith, associate professor and head of the
