vertical-lift bridge

A vertical-lift bridge is a type of movable bridge where the central span rises vertically to allow boats to pass underneath. This design relies on counterweights and machinery housed in two towers to elevate the entire roadway. Unlike other movable bridges like bascule (drawbridges) or swing bridges, the vertical lift allows the roadway to be raised straight up. This engineering solution is particularly useful for accommodating large ships while maintaining a strong structure for heavy loads, such as those on railroad tracks. The Arthur Kill Bridge, for example, has a movable section spanning 170 meters (558 feet) that can be raised 41 meters (135 feet).123