1851

America’s Cup

Imagine a race in which engineers start with a blank sheet of paper and can let their imaginations run wild. This is the essence of the America’s Cup yacht race, which first began in 1851. Yes, there are rules, but within those rules there is a great deal of latitude for engineers. And the designs that appear from such freedom have been revolutionary.

For example, the latest boats can exceed 45 mph (72 kph) on open water. Boat speeds can at times double wind speeds: if the wind is blowing at 20 mph, the boat can go 40 mph. Their sails can be 17 stories tall and rigid. The boats can be quite large—86 feet (26 meters) long by 46 feet (14 meters) wide—and able to hold crews of 11.

How is this even possible? How can a boat powered by the wind travel at 45 mph? The answer lies in multidisciplinary engineering. For example, to keep the boats light and strong they are composed almost entirely of carbon fiber and titanium. To reduce drag, the boats can hydrofoil using small carbon fiber underwater wings that lift the boat out of the water.

The “sails” represent a huge innovation. Imagine removing the wing from a 747 and mounting it vertically on the mast. That is the size of these rigid sails. They are split in the middle, hinged into essentially two wings that can flex in the center, something like a giant flap to change the full wing’s shape. When the wind flows at the correct angle, it is not pushing as it would a traditional sail. Instead it is creating horizontal lift over the upright wing. The lift translates into forward motion.

Between the light weight of the boats, the winglike sails, the hydrofoils, and the well-trained crews, the speeds of these boats have surpassed even the most optimistic expectations.

The size of the sail and the stresses on the foils demand hydraulics. But electric pumps are against the rules. So you will see crew members furiously turning cranks throughout the race. They are the hydraulic pumps for the boat.

SEE ALSO Square-Rigged Wooden Sailboats (1492), Carbon Fiber (1879), Hall-Héroult Process (1889), Titanium (1940), Boeing 747 Jumbo Jet (1968).

The America’s Cup, started in 1851, was one of the first international yacht races.