Detailed design of the catenary in the extension of a tramway system in Wolverhamton, UK

Abstract

The design of a catenary is a complex process, where all the electrical, geometrical and mechanical characteristics of the line, the trains and the surroundings should be taken into account. For this project, the following had to be considered: a proposed layout, the applicable regulations for the design of this type of lines in the UK and the characteristics of the existing line, because the new one had to be compatible with it. Once the parameters of the existing line and the applicable regulation were studied, electrical and mechanical calculations have been accomplished. The long-term operational load and the short-circuit current have been calculated in order to select the appropriate wires (materials, cross sections, etc.). The positions of the supports have been chosen according to the maximum span length that could be achievable, which depended on multiple parameters, such as the tensile forces, the wind load and the radius of the curves. Once the positions were chosen, it should be demonstrated that the loads do not exceed the maximum permitted on wires and, where applicable, on poles. Then, the geometry of the cross-span arrangements, the reaction forces at the supports and the moments on the base of the poles have been calculated, in order to define the position and size of every support, attachment or foundation. There are some key risks to this OLE design: track alignment changes, unsuitability of buildings for fixing to and inability to obtain the permission or statutory powers to make fixings to the buildings identified in the layout. This project has provided a bus, rail and tram interchange to the city of Wolverhampton, facilitating the intermodal transport.