There are two Scherzer rolling lift bridges in the Docklands area of Dublin North Wall Quay and Custom House Quay, Dublin 1 There are three types of bascule bridge, and the counterweights to the span may be located above or below the bridge deck. The fixed-trunnion (sometimes a "Chicago" bascule) rotates around a large axle that raises the span(s). The Chicago bascule name derives from the location where it is widely used, and is a refinement by Joseph Strauss of the fixed-trunnion. The rolling lift trunnion (sometimes a "Scherzer" rolling lift), raises the span by rolling on a track resembling a rocking-chair base. The "Scherzer" rolling lift is a refinement patented in 1893 by American engineer William Donald Scherzer. William Donald Scherzer (January 27, 1858 – July 20, 1893) was an American engineer and inventor who invented the rolling lift bridge.