The Maine state government collaborates with composite research and development and helps achieve the world’s longest bridge.

The world’s longest composite bridge now connects Barter’s Island Road from Hodgdon Island to the coastal town of Boothbay, Maine. This bridge, named the Knickerbocker Bridge, includes 64 award-winning hybrid composite (HC) beams and is anticipated to last over 100 years. The HC beam is a new composite-hybrid technology researched at the University of Maine Advanced Structures and Composites Center (AEWC), manufactured by a local manufacturing company and supported by the state of Maine. This accomplishment is drawing the attention of various Departments of Transportation (DOT) from across the world that want to increasingly design with composite structures.

The Maine DOT funded the Knickerbocker Project, which replaced the 80-year-old wood piling bridge with a 540-foot long installation. The DOT hopes this new technology can also help fix other elements of the U.S.’s deteriorating infrastructure. “As you look around the country, bridges are deteriorating at a high rate. Many of them were built in the 1930’s and have outlived their bridge life. Composites can offer corrosion resistance to infrastructure elements to help them last longer,” says Nate Benoit, project manager at Maine DOT.

Funding Composite Innovation

The state of Maine has been a leader within the U.S. in the development and implementation of composite technology in bridge infrastructure, thanks to the Bridge Innovation and Composite Initiative in 2008, part of a governor’s bill enacted following the collapse of a bridge in Minneapolis. The bill granted an increase in the state’s bridge funding by $160 million over a four year period, including financial support for Knickerbocker Bridge, and encouraged the development of composite technology. The initiative spurred a number of projects between the Maine DOT, AEWC and the Maine Composite Alliance (MCA) including the Bridge-in-a-Backpack and HC beam technology.

The Knickerbocker Bridge Project began in the autumn of 2005 and was originally designed to be a concrete bridge. However, at the end of 2008, after watching the HC beam develop, Maine DOT chose to move forward using hybrid composite technology at a location that would take advantage of composites innate properties such as lightweight construction and corrosion resistance. Knickerbocker Bridge was built close to the water and at high-tide the clearance is only four feet, making it the best bridge in the state to benefit from the corrosion resistant properties and mitigate the effect of salt water.