Modern Cargo Ships Slow to Speed of Sailing Clippers
September 17th, 2010Related: SkySails:
Via: Guardian:
The world’s largest cargo ships are travelling at lower speeds today than sailing clippers such as the Cutty Sark did more than 130 years ago.
A combination of the recession and growing awareness in the shipping industry about climate change emissions encouraged many ship owners to adopt “slow steaming” to save fuel two years ago. This lowered speeds from the standard 25 knots to 20 knots, but many major companies have now taken this a stage further by adopting “super-slow steaming” at speeds of 12 knots (about 14mph).
Travel times between the US and China, or between Australia and Europe, are now comparable to those of the great age of sail in the 19th century. American clippers reached 14 to 17 knots in the 1850s, with the fastest recording speeds of 22 knots or more.
Maersk, the world’s largest shipping line, with more than 600 ships, has adapted its giant marine diesel engines to travel at super-slow speeds without suffering damage. This reduces fuel consumption and greenhouse gas emissions by 30%. It is believed that the company has saved more than £65m on fuel since it began its go-slow.
Ship engines are traditionally profligate and polluting. Designed to run at high speeds, they burn the cheapest “bunker” oil and are not subject to the same air quality rules as cars. In the boom before 2007, the Emma Maersk, one of the world’s largest container ships, would burn around 300 tonnes of fuel a day, emitting as much as 1,000 tonnes of CO2 a day – roughly as much as the 30 lowest emitting countries in the world.
