Balanced Force Pantograph and OCS

At the core of electrified railroad design is the Pantograph and Overhead Contact System (OCS). The design of the OCS has been essentially unchanged for nearly 100 years. The pantograph has undergone structural changes in the last 50 years but it still functions the same way it did over 100 years ago. The technology has proven to be incredibly successful and reliable. However the relationship between the pantograph and the OCS has practical limitations that have become evident in recent times, as trains achieve ever faster operating speeds. Currently the world’s high sped trains all tend to have cruising speeds of about 220 MPH. This circumstance has been referred to in one paper as the Pantograph Barrier. (See Ref #1). The evident limitations on the cruising speeds of electric locomotives comes from several causes. Among these are the maintenance condition of the rails; the radius of curves; the use of roadbed super-elevation; and the presence of freight or commuter trains. But arguably the most pervasive limitation is the behavior of the OCS at higher speeds. History demonstrates the inevitable progress to ever faster rail speeds and the need for ever increasing traction power capacity. This paper will explore the evolution of the pantograph and OCS configuration as a means to identify the limitations that are endemic in the design. It proposes a list of design criteria that must guide the further evolution of the relationship between the OCS and the Pantograph. Further, it proposes a new configuration for the OCS and the Pantograph that may form the basis for the further evolution of the electric locomotives.