Diffenébrücke, Steel bascule bridge in Luzenberg district, Mannheim, Germany

The Diffenébrücke is a steel bascule bridge at the northern harbour entrance from the Altrhein into the Mannheim Industriehafen, linking Luzenberg with the Friesenheimer Insel. Since 1988 two parallel bascule bridges stand side by side, one for road traffic (15.6 m wide) and one for rail (5.5 m wide), each with a 28 m movable span and 33 m fixed approaches. The road bridge clears 11.38 m and the rail bridge 10.60 m at Rhine gauge zero.

The first bridge on this site was built in 1901/02 as a swing bridge, turned by a mechanical device to open a passage for ships entering the harbour. Its load capacity of only 12 tonnes and the narrow passage led to rebuilding plans in the 1960s. Two parallel bascule bridges, one for road and one for rail, were inaugurated in 1988.

The bridge is named after Philipp Diffené, president of the Mannheim Chamber of Commerce from 1880 to 1903. A medal mounted on the structure records the BSVI prize awarded to the new bridge in 1990 by the Bundesvereinigung der Straßenbau- und Verkehrsingenieure.

The bridge carries road and rail traffic between Luzenberg and the Friesenheimer Insel. Since early 2025 the bascule span can no longer be opened because of defects in the hydraulic and control equipment, so shipping currently cannot pass through the lifting section. The structure is 15.6 m wide for the road bridge and 5.5 m for the railway bridge.

The bridge's opening takes 150 seconds and reaches a maximum angle of 82°. Its clearance above the Rhine at gauge zero is 11.38 m for the road deck and 10.60 m for the rail deck. Since early 2025 the bascule span can no longer be opened because the hydraulic and control systems are defective.