Transforming life and reliability of railway overhead electric power lines

As railways are increasingly electrified, service levels depend on an increase in life and reliability of overhead electric power supplies beyond the performance of current materials and technology. Overhead power lines are highly stressed structures without redundancy. Their failure in service is caused by a combination of wear, fatigue cracking, and corrosion, and can be strongly influenced by geometry (e.g. gradient at approach to tunnels). Current collection quality is determined by material behaviour under combined cable tension, the frequency of cable supports, dynamic load from current collection pantographs, and environmental loading (e.g. side winds).

Completion of the project will lend itself to the ongoing commitment by Network Rail to improve the reliability and lowering of the cost in maintaining the existing overhead line equipment. Integration of the research with Network Rail's aims provides a route through which results can be implemented.

Aims and objectives: To establish how novel line materials, components and geometries may offer improved dynamics at reduced cost relative to current systems. This will be achieved through developing an existing finite element model to incorporate the existence of limited clearance cases such as overbridges and level crossings. The research will identify areas of high force on the overhead line equipment through the use of the developed model, enabling investigation of how forces can be reduced or managed, and be used to predict areas that would be prone to failure in the future over an range of conditions.

Novelty of the research methodology: The research will consider materials, components and installation geometries which have not yet been applied in overhead line installations. Research will focus on developing current model of overhead lines to incorporate gradients to predict dynamic loads in areas of the rail network such as over/underbridges and level crossings. Fluid models will also be developed to work with the overhead line model to determine the loads and effects of side winds (e.g. the effect known as galloping wires).

Alignment to EPSRC's strategies and research areas: The research is aligned with the sustainability agenda in producing longer life infrastructure. Environmental change is considered through the effect of increased wind forces on structures. Materials engineering (metals and alloys) is a key factor in selecting novel materials for use in this industrial application. Moreover, the research is aligned well with EPSRC's areas of engineering design, in the sense that we will seek to optimise the design of future overhead lines. With side winds included in the model, this will also align with EPSRC's research areas of fluid dynamics and aerodynamics.

Any companies or collaborators involved:
Network Rail - access to data, field test/measurement sites, and key engineering expertise
Furrer+Frey - co-financing the research, access to data, and key engineering expertise