26. Wilson Dam Bascule Bridge

Donated by: Tennessee Valley Authority
Original Location: Lauderdale County, Alabama
Year Built: 1925
Demolished in 2012
Donated to SBRITE: June 2012

Structure Type: Bascule Bridge
Total Bridge Length: 149 ft
Longest Span: 108 ft
Number of Spans: 2
Deck Width: 26 ft


The Wilson Dam Bascule Bridge was a part of the Wilson Dam that spans the Tennesee River.  In 2008, the TVA proposed to retire or remove the bascule bridge in order to improve the operations of the dam and navigation locks. The bridge was unable to carry heavy loads safely due to its age and deterioration, and therefore could no longer be used for maintenance access. The bridge was originally designed to open approximately 76 degrees, but due to problems with its gear mechanism could only open 58 degrees and hindered auxiliary lock traffic. The bridge was removed in 2012.

A bascule bridge is a moveable bridge that utilizes counterweights to balance the movable spans. The use of the counterweight decreases the amount of power and energy needed to raise or lower the bridge, allowing the bridge to be moved by small motors.  The bridge rotates vertically around the trunnion and rests against a toe and heel joint.