Structure Type Selection and Deisgn Considerations for the Replacement of Two Historic AMTRAK Movable Bridges

摘要

AMTRAK Bridge 116.74 over the Niantic River at East Lyme, Connecticut and AMTRAK Bridge 124.09 over the Thames River between Groton and New London, Connecticut are vital transportation structures serving a major commuter rail line between Boston ad New YOrk. These historic spans were constructed very early in the twentieth cehtury, ad each has great historical significance to the state of Connecticut. Bridge 116.74 is the only chain-driven bascule span on the Northeast Corridor. Bridge 124.09 is one of only two strauss heel trunnion movable bridges remaining in the state. Both bridges have been added to the National Register of Historic Places.