Hardesty & Hanover designed the replacement of the South Bristol Bridge aka the “Gut Bridge” in the historic fishing town of South Bristol. The important bridge, which carries Route 129 and spans the body of water known as “The Gut,” is the only route from the mainland to Rutherford Island, which is where the US Post Office and the South Bristol Fire Department are located.

H&H was initially tasked with progression of the study/preliminary design that was performed by others. The goal during the concept plan development was to modify the preliminary design created by others as required to address all operation and reliability concerns for this movable bridge and then accurately estimate the associated construction cost and construction schedule so as to allow the Department to work within a construction budget while addressing all schedule constraints.

Our final design took the concept plan development and progressed all structural, mechanical, electrical, geotechnical, and civil design for this movable bridge, while also incorporating concerns from the local community. The movable span is a harp style bascule that is fully counterweighted and driven by two 15 hp motors rotating the span 80 degrees to an open position through a rack and pinion system. The movable span carries two lanes of roadway plus a sidewalk and measures 35 feet in width. The span measures 42 feet 7 inches from centerline of trunnion to toe and spans a 33 foot 6 inch wide channel.

Significant schedule, staging, cost, alignment and geotechnical challenges were all addressed during design. After completion of the PS&E, we assisted MaineDOT in putting this movable bridge construction project out for bid by contractors. The bridge opening ceremony was held on May 25, 2016.

The project has won an ENR New England Best Project of the Year Merit Award, Grand Concepter Award from ACEC Maine and an American’s Transportation Award from NASHTO.