High-tech sails to benefit commercial shipping
July 5, 2007 For four hundred years majestic tall ships ruled the world’s oceans carrying cargo and migrants to far corners of the globe, but the advent of steam power in the late 19th century brought the golden age of sail to an end and rendered wind-powered vessels obsolete – but did it? Recent projects in both Europe and the U.S are seeking to breathe new life into this “old technology” and once again give sail-power a viable role in commercial shipping. The new era of sail-power wont see the return of square rigged barques or clipper ships, but rather the introduction of high-tech kite sails that generate greater propulsion power than conventional sails. These can be used to supplement the propulsion systems of all kinds of cargo vessels and in the process generate economic benefit, reduce reliance on fossil fuels and deliver emission reductions in a sector that has become one of the world’s biggest polluters.
Kite For Sail LLC, is a project underway in the waters off Hawaii that utilizes kite-sail technology to harness higher atmospheric winds than afforded to conventional sail configurations. The brainchild of Dan Tracey, a sailor and fisherman from Maine, the project began in 2004 with the modification of an 18 foot Hobie Catamaran for use as the first test boat and subsequent development of dozens of prototypes culminating with the current R&D vessel - an F24 Corsair trimaran fitted with a kite-system that is used as the primary power source.
Currently being tested on a fishing vessel in North Shore, Maui, the trimaran’s engine is still used in light winds and to manoeuvre the vessel into launch and docking position but the primary power source is the 18-meter kite system. A recent trial saw the vessel achieve between 7 to 10 knot boat speed without the use of the engine in 4 to 8 foot wind swell and winds of between 15 and 20 knots with four crew aboard and trolling two lines. The only downside according to Dan Tracey was the lack of fish.
The project is assisted by Dan’s twin brother Chris, a NASA mechanical engineer who has been brought in as a consultant on the latest state-of-the-art materials, construction and design possibilities and Ian Fisher is an accomplished Maui waterman who knows local Hawaiian wind patterns, coastlines and currents. Over the next 5 years the team is planning kite-sail voyaging throughout the Hawaiian island chain to the mainland USA and around the world.
Kite For Sail LLC is currently discussing sponsorship with companies interested in Eco kite-sail promotion as well as developing funding avenues to support wind power development for ocean going vessels which stand to benefit from this economically sound and environmentally friendly technology.
SkySails is developing, producing and distributing a towing kite wind propulsion system that is retro-fittable on virtually all cargo ships.
The planned kite propulsion systems can deliver fuel savings to large vessels of approximately 10-35% which can stretch to 50% under ideal wind conditions. According to SkySails this translates to annual savings of up to 280,000 euros on a relatively small 87-metre cargo ship.
The SkySails system includes a highly-efficient parafoil kite with areas ranging from 160 to 5,000m that achieve optimal aero-dynamic efficiency at any wind speed whilst enabling the power to be cut-back in case of very strong winds via the adjustment of the kite’s position relative to the horizon. The system is steered automatically via in-built software and can be configured according to the wind direction, wind force, ship route and ship speed. Automatic launch and recovery of the kite takes between 10 and 20 minutes via a dynamically operating winch and a telescopic mast that lifts the towing kite stored in a container situated above or below deck depending on the ship.
This year has seen the introduction of SkySails-Systems with towing-kite areas of up to 320 square meters that can be used for cargo vessels, superyachts and fish trawlers. Full production will start in 2008.