In Wilhelmshaven, a by-pass is only slightly above the level of the harbour channel so that a bridge with movable bascules is necessary to allow the passage of ships.

The by-pass relieves the centre of the town, while the harbour channel connects the navy arsenal with water access to the North Sea.

The bascule bridge is opened by hydraulic means six or seven times a day for the navy ships.

The bearings in the bascules have the following characteristics:

• they swivel at a very low sliding speed

• they must compensate angular misalignment when opening and closing

• they are exposed to sea air, which has a strongly corrosion-inducing effect

• they must run without lubrication, since they are subjected to unilateral loads such that the lubricant would be forced out of the load zone.