DEPTH OF BALLAST, FORMATION FAILURE, ASSET MAPPING
Example (right) 0.25mi of GPR data (a) collected on Network Rail’s UTU3 inspection train. Changes in the thickness of the primary ballast layer (b) are clearly indicated in a ‘Manhattan Skyline’ plot (c) as deviations from the design depth.
Figure (below left) shows a section of track before relaying works took place.
Figure (below right) shows the trackbed following extensive upgrade works. The works allowed line speeds to be increased from 70mph to 125mph on a main line in the UK.