America's team BMW Oracle Racing (BOR) has taken full advantage of a "wide open" set of design rules for this year's America's Cup to produce one of the most staggering and ambitious vessels ever seen on the water. Throwing out the cloth main sail, team BOR have fitted the BOR 90 with a gargantuan, motorized, solid carbon-fiber wing, nearly twice the size of a Boeing 747 wing at 190ft, or 57 metres tall. The engineering and logistics surrounding this incredible boat are mind-boggling - imagine trying to work out where to store the giant wing structure, how to transport it and how to fix it vertically onto a boat - let alone how to sail the thing - but the benefits of a non-deforming main sail include the potential for the multimillion-dollar trimaran to travel at up to 2.5 times wind speed. It's a crazy, massively expensive and hugely risky experiment that's never even been prototyped, and will only get a few weeks' worth of testing before it races in February.

Here's a few numbers on the BOR 90's wing sail - by far the largest wing ever fitted to a boat. At 190ft, or 57 metres tall, it's 80% bigger than the wing of a Boeing 747. At 7,770 pounds (3,524kg), it's considerably heavier than the 6,000lbs of a Hummer H2. At its widest point, it spans 30 feet (9 metres) and it has a total surface area of 6725 square feet (625 square metres).

It's built from carbon fibre and kevlar, with an ultra-smooth aeronautical film cover to ensure maximal airflow. Building the wing alone took nearly 40,000 man hours.

Such a massive wing can't be operated by manned ropes alone; instead, due to a loophole in the challenge rules, it's actuated by motors that control the master wind rotation, the camber of the main flap area, and the specific angle of rotation of each one of the eight separate flaps that hang off the trailing edge of the main wing.

The boat itself is a gigantic racing trimaran, its footprint the size of two basketball courts, featuring wave-piercing, heavy bows to give it a smooth ride through choppy seas.

The benefit of having a wing as opposed to a traditional fabric sail is that the wing never deforms against the wind - its shape is constant, and with the flap system taken into account, its shape can be very precisely controlled. Combined with the trimaran hull, the wing should allow the BOR 90 to sail into a headwind at angles less than 30 degrees - and, rumour has it, in ideal conditions to make it up to 2.5 times wind speed.

According to BMW, the design deadlines on the wing sail were so tight that as soon as the CAD designs were finished, the wing went straight into production - there was no time for prototyping or testing. And while the wing may deliver substantially more power and flexibility than a regular sail, learning to make use of its rather unique characteristics in such a short amount of time is a herculean challenge for skipper Russell Coutts and his crew.

It's the equivalent of McLaren putting a new engine in its F1 cars without ever having dyno tested it - as close to seat-of-the-pants racing as you can get in a multimillion-dollar race series of such a high profile as the America's Cup.

What's more, the wing is supported by a shroud and forestay wires that actually prevent it from rotating 360 degrees - so there's a possibility that, given some very specific wind conditions, the wing might catch against these wires, which opens up the possibility that the whole thing might break or capsize the boat.

Mind you, this isn't the first time a wing sail has been raced in the America's cup - famed aerospace designer Bert Rutan, the engineer behind Virgin Galactic's commercial space-liners, was part of the team that put together a wing for 1988's Stars and Stripes - which went on to dominate that year's Cup race. But the BOR 90's wing is nearly twice as long as the one on the Stars and Stripes.

The BOR 90 was assembled once in the harbour of San Diego, and sailed - check out this video, which will give you some sense of the scale and logistical complexity of this phenomenal operation:

It has since been shipped to Valencia, Spain for the 2010 America's Cup, which will begin in early February. The boat was assembled and made its debut on Spanish waters yesterday - giving the team precious few opportunities to practice and learn this amazing new beast before it goes up against the defending champion, team Alinghi with its new boat, a 90ft catamaran called Alinghi 5.

You could view this challenge as a battle that pits deadly fast, proven tech and knowledge against a competitor that has bet the farm on risky technology with the potential to deliver massive performance if they've built it correctly and worked out how to use it by the time the flag drops. And remember, this is the oldest and most prestigious sporting event in the entire world - astronomical sums of money are at stake when the two boats face each other.

We wish both teams the best of luck and look forward to some spectacular racing from this jaw-dropping boat.

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