Modelling electrical power interfaces at level crossings

At level crossings, the overhead contact line (OCL) must be raised to allow high road vehicles to pass safely underneath. Our project ‘Contact Wire Heights at Level Crossings’ (COF-UOH-49) reviewed the height requirements for OCL wire at level crossings to provide recommendations for limits to be included in the relevant standards.

Raising the OCL comes with a potential reliability risk to the railway: higher wire heights with fully extended pantographs can be prone to contact problems, particularly in high winds. The construction costs of electrification can also be higher if bridges adjacent to the level crossing need to be modified or demolished.

The research objectives were:

• To establish a rationale for the minimum OCL height at level crossings and the technical challenges faced by installers and infrastructure managers.
• To assess the pantograph-catenary dynamic performance at level crossings, analysing the influence that the different pantograph modelling approaches, gradient steepness and aerodynamic effects have on the current collection performance.

The case studies of this research demonstrated that the pantograph models are almost non-sensitive to the contact wire height variations when aerodynamic loads are not considered. However, experience demonstrates that in-service, the pantograph-catenary contact forces are expected to increase as the contact wire goes up due to aerodynamic effects. Therefore, the multibody pantograph model was used to exhibit the behaviour experienced in service.

These research findings contribute to cost savings in new electrification projects and upgrade or renewal of existing catenary systems. The research findings also open up the possibility of being able to have higher train speeds at steeper gradients.