The control centre for the swing bridge at Preston Docks

Preston used to have a thriving set of docks but they have longed ceased to be commercially viable. The river Ribble, which connects the docks to the sea, is no longer dredged to any great extent so the types of sailing craft that can use the place are limited.

The areas around the dock have been redeveloped with housing, retail shopping, and a lively marina. The Ribble is tidal at Preston so that boats have to wait to leave and enter until the tide conditions are right. The rest of the time the water in the docks is held back by massive dock gates. A road runs around the site and crosses over a swing bridge near these gates. This building houses the controls that operate the bridge hydraulics rams when taller boats need to leave the inner dock.