Tomlinson Lift Bridge

The Tomlinson Lift Bridge is a crossing of the Quinnipiac River in New Haven, Connecticut. The bridge forms a segment of U.S. Route 1. The Tomlinson Vertical Lift Bridge carries four lanes of traffic across New Haven Harbor and a single-track freight line owned by the Providence & Worcester Railroad that connects the waterfront with the Northeast Corridor line of Metro North and CSX. A sidewalk is present along the southern edge of the bridge.

History
The first bridge here was erected in 1797 by Isaac Tomlinson's group to replace profits from their ferry ruined by a new bridge. This 27 ft-wide covered wooden truss bridge included a draw to allow vessels through. It has also been described as a "wood and sandstone" bridge.

The second bridge, 1885-1922, was an iron bridge which was never particularly good, having been salvaged from a scrap yard, and not thought well of even before then. By 1913, this bridge was opening 17,000 times a year. Plans for replacement were created during World War I.

The third bridge on-site was a trunioned double-leaf bascule drawbridge with its counterweights in a closed pit underneath, built between 1921 and 1924. It was designed by engineer Ernest W. Wiggin of New Haven in the Beaux-Arts style, based on a bascule design by Joseph B. Strauss. Before the completion of the adjacent Q Bridge, it was carrying 30,000 vehicles a day. When closed, clearance under the bridge was 12 ft at mean high water, ranging from 8 - 17 ft at extreme high tide to extreme low tide. The channel width was 117 ft, with a total span length between centers of 148 ft. The builder was the Phoenix Bridge Company of Philadelphia, Pennsylvania.

The current bridge, the fourth one on this site, is a lift bridge 270 ft long and 92 ft wide, a significant improvement from the previous (third) bridge's 117 ft channel. The mechanism raises the lift span 62 ft with 3000000 lb counterweights on each of the two 150 ft towers on either end. The bridge cost $120 million, designed by Hardesty & Hanover LLP of New York City, is 90 ft wide and 270 ft long with two 30 ft tower spans and six 100 ft-long approach spans. The lift span weighs almost 6500000 lb with a total load-to-move of 13000000 lb. It provides a channel with 240 ft horizontal clearance and 13 ft vertical clearance when the span is closed, and an additional 62 ft vertical clearance when it is open.

The project was part of the New Haven Harbor Crossing Improvement Program Securing the bridge's lift piers initially proved difficult because rock elevation and slope differed along the route. To secure the piers, teeth were welded to the tip of 20-in-diameter pile shells that were then drilled into the bedrock. For some piles, an adequate seal was not achieved until the pile had been seated into 5 ft. of bedrock.