JUST before the America's Cup yacht oneAustralia folded in half March 5, skipper John Bertrand heard a sound like a cannon going off.
It was the sound of the boat's carbon-fiber skin snapping.
``Carbon fiber is very very stiff, and when it breaks, it explodes,'' says Eric Goetz (pronounced ``ghertz''), who builds carbon-fiber sailboats in his boat yard here.
Goetz is quick to detour any finger-pointing at the space-age material, however. ``Carbon fiber is not the bogeyman,'' he says. The reason for oneAustralia's dramatic collapse in 22 knots of wind, he says, is a fault somewhere in the design, engineering, or construction.
If anyone knows about carbon fiber, it is Goetz. He's built more America's Cup yachts with the exotic material than any other builder in the world. In fact, all three American defenders - Team Dennis Conner, America3, and PACT 95 - hired Goetz to build their boats. He also built the successful defender of the 1992 Cup.
Many consumers know carbon fiber as graphite, used in making bicycles, tennis rackets, and golf clubs. It is also used in the stealth bomber and the doors of space shuttles. ``Carbon fiber is five times stronger than an equivalent-weight piece of steel,'' Goetz says.
Carbon fiber is not only stronger, it is also stiffer. Most sailboats are made of fiberglass, which flexes slightly when the boat hits a wave. Since carbon fiber is 40 times stiffer than fiberglass, the power from the sails is more directly translated into boat speed.
Nevertheless, carbon fiber doesn't weigh much. ``With a sailboat you want as light a structure as you can build; then when you push it around with the sails, you don't have as much resistance,'' Goetz says.
Despite the material's great strength, it does have its vulnerable moments, as some of the BOC around-the-world sailors recently discovered. When Frenchwoman Isabelle Autissier's boat fell off the top of a large wave, the carbon-fiber cabin roof crumpled. American BOC competitor Steve Pettengill had to slow down when he discovered that a carbon-fiber bulkhead had cracked.
``Carbon fiber is a wonderful material as long it keeps its shape. But if it gets too far from the design shape, it can shatter,'' says Tony Lush of Newport, R.I., who has raced across the Atlantic.
It is likely, however, that carbon fiber will remain the material of choice for the America's Cup. ``These boats are racing machines,'' says Goetz, who compares them to Formula One race cars.
While conventional yachts are not cheap, carbon-fiber America's Cup boats are off the scale, price-wise. A 23-meter (75 foot) Cup competitor costs $3 million to $4 million. A conventional 75-foot sailboat costs about $1 million.
The high cost makes it critical that a boatbuilder come in close to budget. ``That's Eric; he sticks to his budget,'' says Gary Jobson, a sailing analyst for the ESPN cable-TV sports channel.
``He not only builds on budget and on time, he often comes in under budget and ahead of schedule,'' adds Bill Koch, the Kansas oil man bankrolling America3.
Koch adds that Goetz can take a drawing from the back of an envelope and make it into a working part. When Koch asked a Wilmington, Del.-based aerospace company to build a boat for him in 1992, on the other hand, Koch says the company wanted 10 drawings for every part.
Since the boats are so expensive and on the cutting edge of technology, Goetz gives more than lip service to security. ``When you put this much money into a boat, you don't want the other guys to see what you are doing,'' he says.
To make certain that competitors would not see one another's boats, Goetz leased extra space about half a mile from his unmarked factory. That way he could build two boats at the same time.
Not only does Goetz have to watch what he says, so do his 30 workers. ``We talk about it among ourselves, and explain that someone might want to take you out for a beer and ask about this or that,'' says Goetz, who adds that his workers have been tempted with cash payments to divulge secrets.
THE temptations may have merely been attempts to see if the yard was truly secure. Koch recalls ``agonizing'' over whether to use Goetz in 1992. Koch says his workers did not directly offer money to Goetz's workers, but ``we hinted we would do that,'' Koch says. ``Our guy would say, `It sure would be valuable to see that [Conner's] boat,'`` Koch adds. Goetz's workers passed the test with no problems.
Goetz also kept his mouth shut when America3 decided to use a lighter and stronger material in the core, which separates the inner and outer skin of the boat. The Koch team used an aluminum-based honeycomb for the core. The purpose of the honeycomb is to give the boat stiffness while keeping the weight down.
At the same time, Conner was building his boat using Nomex honeycomb, a more traditional material.
``Aluminum is a little stronger - for the same weight - than Nomex, but I couldn't say anything,'' Goetz says.
Despite his confidence in carbon fiber, Goetz would like to see oneAustralia pulled from the bottom. After repairs, he says, the boat would be too heavy to be raced. (The Australians plan to keep racing in an older boat.) But, he adds, ``I am sure all the boatbuilders and designers would like to know what happened.''