The age of sail could be staging something of a comeback as part of an attempt to cut greenhouse gases on the high seas. German engineers have devised a way of tugging merchant vessels and superyachts along with huge, computer-steered kites, known as SkySails that catch the ocean winds.
Today the first new cargo ship to harness wind power in well over a century will be launched in Hamburg, with the maiden journey taking the 10,000-tonne MS Beluga Skysails across the Atlantic to Houston.
If the Beluga performs well on wind power and if the high-flying kites dramatically cut its fuel consumption, then the age of sail will be back.
'It marks the beginning of a revolution in the way that ships are powered,' said Stephan Wrage, the inventor of the SkySails idea. 'We calculate that the sails can reduce fuel consumption by between 30 and 50 per cent, depending on the wind conditions.
'The system could be applied to about 60,000 vessels out of the 100,000 or so listed in the Lloyd’s register. Bulk carriers, tankers — they could all benefit from the flying sails.'
If he realises his dream of re-equipping the world fleet, Mr Wrage calculates that his sails could save 142 million tonnes of CO2 a year, equivalent to about 15 per cent of Germany’s total emissions.
The problem is huge. Merchant ships, which carry 90 per cent of the world’s merchandise, produce more sulphur dioxide than all the cars and lorries on the planet. And, according to the International Council on Clean Transportation, they also generate about 27 per cent of the world’s nitrogen oxide emissions.
Wallenius Wilhelmsen Logistics, the Norwegian fleet management company, has designed a green flagship, the Orcelle, which will use rigid, rotating sails to capture the strongest winds.
When the wind drops the sails can be used as solar panels. But the company admits that it could take 15 years before the ship is developed.
This is how it should work -
Mr Wrage believes he has solved the problem of reducing engine power while maintaining speed. 'As soon as the winds are strong, the captain can throttle back using our system,' he said. 'Maybe he won’t cut the engine entirely, but he can rely on the sails.'
In the great 19th-century battle of the seas between sail and steam, steamboats usually had masts and auxiliary sails to give them some extra speed. But by the 20th century, the power of wind was being dismissed as an anachronism, primitive and unpredictable.
'That was because sails were fixed to on-deck masts and were vulnerable to the whims of the winds on the surface of the sea, sometimes dipping, sometimes picking up,' says Mr Wrage. 'The strength of the SkySail is that it operates at a height where the winds are strongest and most stable.'
The sails, made of an ultralight synthetic fibre, are shot up as much as 300m (984ft) into the sky. A computer console on the bridge feeds in data on wind strength and direction. A track running around the ship allows the kites to move and scoop up the wind from virtually every direction.
'The sails are environmentally friendly and can save me a load of money,' says Niels Stolberg, owner of the Beluga line who might — if the maiden voyage goes well — end up buying the system for his entire fleet of 47 vessels.
Mr Wrage calculates that most ship owners should be able to recoup their £290,000 investment in the kite sails within three years.
But for some the idea is about more than saving cash, and the planet. It is about the adventure and beauty of sails. 'If you learned to sail at the age of eight, like me, sailing enters your bones,' said Mr Stolberg. 'And you get a feel for the wind, its power.'
Skysail 1 -