Railbreaks

Client Type:  Main line operator

Objective

To inspect and classify broken and defective rails across a large proportion of the network and to identify trends occurring over a set period of time.

Approach

The first stage of the project required identification of relevant personnel at a large number of regional maintenance depots spread across the network.   The Corus team developed productive working relationships with these people to ensure that broken rail samples and related documentation were retained for use in the investigation.

The multi-disciplined Corus team undertook visual inspections and detailed metallurgical investigations to identify the root causes of broken rails.

Method

Key steps in the methodology adopted for this project were:

• Primary visual examination of samples at maintenance depots.
• Initial classification of samples and transport of selected samples to laboratory for further investigation.
• Secondary visual examination followed by non-destructive testing – techniques used included magnetic particle and dye penetrant inspection, ultrasonic testing and eddy current testing.
• Metallographic and microscopic examination of samples including sectioning, grinding, polishing and etching to determine cause of failure.
• Final classification of samples in accordance with the client’s own standard for broken rail root cause analysis.

At the request of the client, rails that were removed from track because they contained track defects were examined in order to determine the extent of defect development and to better understand defect propagation.

Deliverables

Corus delivered a series of reports containing recommendations for action  and detailing the findings of its investigative and analytical work.  The reports included:

• Classifications for all broken rail samples examined and details of the proportions of each identified failure mode.
• Analysed correlations between other rail-related information and the broken rail classification.
• Details of the identified metallurgical root cause of failure and recommendations regarding relevant control strategies.
• Details of the trends seen on a regional and national basis - identifying areas of best practice across the network.