Thames River Bridge (Amtrak)

Amtrak's Thames River Bridge spans from New London to Groton, Connecticut, United States, crossing Connecticut's Thames River.
Design and history.
The bridge was originally a Strauss heel-trunnion Warren through-truss bascule design, built in 1919. It was built by the American Bridge Company for the New York, New Haven and Hartford Railroad, replacing a span dating from 1889. In June 2008, the bridge underwent replacement which included the span's conversion from a bascule to a vertical-lift mechanism.
As built in 1919, the bridge's abutments and piers were designed to carry a second set of double-track spans, in the event that an expansion to four tracks was ever undertaken at this location by the New Haven Railroad (it never was).
Operation.
The bridge opens for marine traffic more than four times per day and serves up to 36 passenger trains and two freight trains per day. The bridge sits above mean high water (MHW), and the vertical lift span opens to above MHW and provides of horizontal clearance.
It is one of eight moveable bridges on the Northeast Corridor through Connecticut surveyed in one multiple-property study in 1986.