Brookfield Floating Bridge Wins Two Industry Awards in New England

T.Y. Lin International (TYLI), a globally recognized full-service infrastructure consulting firm, announces that the new Brookfield Floating Bridge, which crosses Sunset Lake in Brookfield, Vermont, has won two industry awards in New England. The project won Best Highway/Bridge Project in the Engineering News-Record (ENR) 2015 Best Projects New England competition, which honors top projects in Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, and Vermont. The Brookfield Floating Bridge also received a 2015 Special Recognition Award for Engineering Excellence from the American Council of Engineering Companies (ACEC) of Maine.

TYLI served as prime design consultant for the Vermont Agency of Transportation (VTrans) on the bridge replacement project, which transformed an aging floating structure into a state-of-the-art, fiber-reinforced polymer (FRP) pontoon system that has a life expectancy of 100 years. The TYLI team performed an alternatives investigation and carried the selected alternative through final design and PS&E submittal. Rebuilt seven times since its original tied-log construction in 1820, the 321-foot-long floating timber bridge is listed on the National Register of Historic Places as a contributing element to the Brookfield Historic District.

Design criteria included a durable, maintenance-free structure that could weather highly-variable ice pressure loads, even when closed during the winter, and the integration of modular components to aid in potential major repairs. TYLI’s preliminary design compared concrete and FRP for the pontoons. VTrans selected TYLI’s innovative FRP alternate because dredging of the lake would not be required and the FRP pontoons could be filled with closed-cell foam for a secondary flotation system.

One of only a handful of floating bridges in the world, the Brookfield Floating Bridge carries a single 12-foot-wide travel lane for alternating, one-way traffic and two flanking 5-foot-wide sidewalks. The articulating approach ramps consist of glued laminated timber beams. Timber was used for the deck, railing, and ramp system to echo the appearance of local historic structures. The bearings and hinged expansion plates were uniquely designed and detailed to accommodate large movements caused by lake-level fluctuations. The abutments are traditional cast-in-place concrete, with one abutment supported by a shallow footing on bedrock and the other pile-supported.