vertical-lift bridge

A vertical lift bridge is a fairly common type of openable bridge, whose deck remains level as it is lifted by mechanisms on two parallel towers at either end. The span is usually lifted by cables with counterweights, but can also rise on hydraulic jacks.

This type is common for railroad bridges because it is generally efficient at supporting heavy loads.

The span remains level while changing elevation. This distinguishes the movement from a hinged leaf that tilts upward; railroad use is common but is not required.