Case studies
UK:
Zetica’s contract to scan 16,000km of track in the United Kingdom for Network Rail with ground penetrating radar (GPR) systems mounted on an ultrasonic inspection train has been extended. ZARR will now be fitted to an additional two inspection trains to increase annual coverage to over 24,000km. A combination of high resolution scanning of ballast/sub-ballast layers and identification of deeper secondary layers in the sub-ballast/sub-grade section has proven to be very successful in meeting the primary project aims.
The savings realised by Network Rail in implementing ZARR have been significant. ZARR has been directly responsible for impressive cost savings in site investigation and significant improvements in efficiencies by accurately defining the scope of renewals required. By using the GPR results for desktop analysis, Network Rail’s renewals team has adopted the method of targeted trial holes focused on the areas of obviously change to ensure all zones of disturbed ballast are appropriately investigated. This has led to a 50 per cent reduction in the number of trial holes excavated when compared to the original method of excavating trial holes at every 50m.
The use of the GPR data within the renewal assessment process has also led to sites being withdrawn from the renewal programme on the basis that the GPR data, supported by trial hole data, did not justify ballast renewal. Other sites have had the original limits and scope of work changed to ensure that the appropriate mileage and depth of renewal is undertaken. The longer-term benefits of reduced maintenance intervention and the elimination of the risk of a costly revisit will lead to significant savings.
The successful trial and planned roll-out to an additional two trains reflects the professional efforts by our rail team and the E&D department at Network Rail to ensure that the high volume output from ZARR is always available on time to track engineers for planning maintenance and renewals.
USA:
Zetica has been awarded the first commercial-scale GPR rail scanning project in the USA by one of North America’s largest rail companies, who are responsible for over 30,000 miles of track. The surevy will cover 3000 miles of track and will be used to assess the value of ZARR in helping to improve the return on investment in track works programmes.
For this project, our customer’s main focus is the quality of ballast on the shoulders and in the four-foot. A specially modified road-rail vehicle and software system for integration of the results with our client’s track management database is being provided.
Ireland:
Zetica is providing a service to deploy ZARR based on a track recording vehicle, interfacing four channels of GPR with video, location and distance measuring systems. A combination of high-resolution scanning of the ballast and deeper imaging of cross-cutting services is required.