A balance bridge is a type of mobile bridge that is built over navigable canals in order to facilitate the passage of vessels underneath without the need to raise the road layout. They are made up of one or two sections that open in a direction perpendicular to the plane of the bridge with the help of counterweights located under the platform.

The drawbridge is a similar bridge but with a different use, defensive in nature, and with a single piece.

These bridges are more complicated to build than fixed ones and have a higher budget. They are usually built in the passages of boats so that boats can pass under them.

James Meadows Rendel&action=edit&redlink=1 "James Meadows Rendel (engineer) (not yet written)" erected the first bascule bridge with a hydraulic mechanism in the Kingsbridge estuary in England in 1831.[1]​.

It was designed by the Spanish civil engineers Leonardo Férnandez Troyano and Javier Manterola Armisen[2]​ within the framework of the preparation for the 1992 Universal Exhibition in Seville.

It was built between 1988 and 1990 by the Dragados company and the Construcciones S.A. company. Its purpose was to replace the Alfonso The new bridge was more functional and modern than the one from the 1920s.

The Barcelona Harbor Bridge, Spain, is a typical example of a bascule bridge and is currently the largest double bascule bridge in the world. The four tilting pivots are equipped with large GE670 DW ball joints (inner diameter 670 mm) with ELGOGLIDE® coating. The actuating hydraulic cylinders are attached to the adjacent construction with maintenance-free joints. In this case, ball joints with inner diameters of 260 mm and 280 mm were used. Each leaf of this impressive structure measures 70 meters long and weighs approximately 2000 tons.