Community New Haven and Hamden Bridges
The Pearl Harbor Bridge in New Haven, CT, commonly referred to as the "Q-Bridge", is in serious need of repair and is receiving just that attention. It is old, deteriorating, and is congested with 140,000 vehicles per day. It was designed for only 40,000 vehicles per day. The bridge will move from three lanes to five lanes and from one six lane bridge to five two lane bridges. The project will include other enhancements that will allow easy access and exit lanes onto and off the bridge. It will be longer than the original bridge because of the enhancements that also include operational and safety improvements.
The bridges design is unique because it is a first of its kind. The tension design is called an extradosed bridge. Its design is a combination of a concrete girder bridge and a cable-stayed bridge. The benefits of this type of bridge are shorter towers and less girder depth which allows for longer straight span lengths than the traditional cable-stayed bridge and girder bridge. The cables do not need tension adjustment which will reduce maintenance costs. The expected completion date is in mid-2015 and the projected cost is $417 million.
The Tomlison Bridge, also in New Haven, CT, is a vertical lift span drawbridge. It was a $120 million project that took 10 years to complete. It is the largest vertical lift span drawbridge east of the Mississippi River. The bridge is composed of four lanes that cross over the New Haven Harbor and alongside is a single-track freight train line.
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Some construction facts of the bridge are: The bridge is 90 feet wide and 270 feet long with six 100 feet long approach spans and two 30 feet tower spans which were erected from the water. The vertical lift spans weigh nearly 6.5 million pounds with a total load-to-move of 13 million pounds. It provides a channel with 240 feet horizontal clearance and 13 feet vertical clearance when the span is closed and it supports 17 million pounds of steel.
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Trowbridge in New Haven, CT is a stone arched bridge. It was named after the family that funded its construction and is located on Trowbridge Drive which is a park road in East Rock Park. It was constructed in the late 1880s and like all old bridges it shows its wear. Its stone masonry construction has moss and small plants everywhere on its surface but this bridge is not widely traveled and so it is not in deterioration.
Figure 4: Trowbridge constructed in the late 1880s.
Next to the Eli Whitney Museum in Hamden, CT is the Major A. Frederick Oberline Bridge also located at East Rock Park and dedicated to the memory of Major A. Frederick Oberline who was an eminent soldier and citizen. His commemoration is inscribed on a plaque inside the bridge.
Figure 5: The Major A. Frederick Oberline Bridge showing a lattice design.
The wood covered bridge, originally located at a different site, was washed out during a flood. Its' simple design of closely spaced diagonals and overlapping triangles made the bridge strong, economical, and easy to build. The bridge was constructed as a lattice-truss bridge so that the stresses of the bridge were evenly distributed over the triangles. In 1979, Eli Whitney VocationalTechnical High School students reconstructed the above bridge where it currently stands.