Nature isn’t always the culprit when infrastructure suffers damage. Sometimes the harm comes from human error. Composites are just as resilient in these situations.
Operators of barges and other boats on the U.S. waterways occasionally collide with electrical transmission towers or with unprotected bridge supports. “Ten years ago, a large ship hit a bridge in Florida, and it had to be shut down,” Reeve says.
The owners of these structures surround them with fenders (fences) for protection. But the steel and wood structures that are typically used aren’t ideal in this environment; the steel corrodes, and preservative-soaked wood may contaminate the water.
Composite Advantage has installed FRP fenders in the James River and along the New Jersey coast. Composite poles, some 100 feet long, anchor these fences, with FRP cross braces filling the span between the poles. If a boat collides with them, the FRP fenders bend and return to their original shape, unlike those made of wood and steel. They also cause less damage to the ships that hit them.
Ferry terminals also benefit from fenders produced by Composite Advantage. “When the ferries come in the wind is blowing, the currents are moving and a lot of times the ferries are coming in fast. In bad weather, a ferry can hit hard enough that people and motorcycles fall over,” Reeve explains. “When the ferry hits fiberglass fenders, it’s a much gentler impact because there’s more give. We bend, but we don’t break.”
Although the FRP piles cost more than wood or steel, the flexibility of the composite material allows the installation of fewer piles overall. That means less costly pile driving. “Even though the product price of the materials delivered to the site is higher, when they get done with the actual installation the whole project cost is lower,” Reeve says.