Corrugation Survey
Survey of track to provide benchmark data for targeted grinding programme.
Synopsis
Tramway networks suffer from degradation of the rail through corrugation. Addressing this problem requires the use of rail grinding machines. Typically, they are provided by an external contractor, contracted to deliver a planned number of shifts. Client costs can amount to approximately £5,000 per shift. The client needed to be able to target this activity to derive the greatest commercial benefits. Benchmarking the entire network was required to enable the client to do this. A survey of the track was required to provide benchmark data for a targeted grinding programme.
Key Client Issues
The network suffered from rail corrugation. This has the appearance of periodic undulations in the longitudinal profile of the running surface. Before the benchmarking survey, the client scheduled remedial grinding on the basis of subjective assessments of corrugation throughout the network without any quantitative data to direct decision making. This tended to result in an ad hoc approach to a high cost maintenance activity with the very real risk of some severely degraded locations being missed.
Corrugation causes:
- Passenger discomfort
- Increased noise
- Increased track damage
- Increased vehicle damage
Solutions
Corus conducted a survey of the entire network at night to identify the extent of corrugation throughout. A survey of this nature requires specialist equipment to capture corrugation data as it passes along the track. Subsequent data analysis provided the information needed to prepare a report for the client with user friendly outputs, giving a visual representation for grinding priorities. This enabled the client to plan for the medium to long term - providing the best value for money to be obtained from an expensive but essential maintenance process. Key outputs included:
- Data showing severity and location of corrugation throughout the network
- The production of a complete network “map” to visually identify the locations and priorities for grinding as immediate, 1 year hence and so forth
- The optimum depth to which grinding should extend in each instance
Client Benefits
Our report enabled the client to:
- Have a snapshot of the current extent of corrugation on the network and benchmark the system for the future
- Implement a planned corrugation maintenance programme
- Manage maintenance more cost effectively by targeting grinding in the short, medium and long term
- Improve ride comfort for passengers
- Reduce the risk of disruption for passengers
Finally, following maintenance, we undertook post-grinding inspection to confirm whether the work completed satisfied the specification.
