Monitoring the dynamic displacements of railway track

Abstract

This paper reports the development and testing of two independent, innovative techniques for measuring rail displacements. One system combines remote video monitoring with particle image velocimetry, using a webcam and a small telescope. The second uses sleeper mounted geophones that give a voltage output proportional to the velocity of motion, which can be filtered and integrated to calculate displacements. Laboratory validation tests show that the video monitoring system can measure peak-to-peak displacements to within 0.04 mm from a distance of 15 m for frequencies less than 4 Hz. The geophones measure peak-to-peak displacements to within 0.07 mm for frequencies as low as 1 Hz. Data from three different standards of railway track and/or train speeds are used to explore and quantify the limitations of each system in the field.

The behaviour of railway level crossings: Insights through field monitoring

“…Bowness et al, 2007;Priest et al, 2013;and Coelho et al, 2011). A short summary of the data they provide and their interpretation follows.…”

“…Geophones and digital image correlation (DIC) of video images following the principles described in Bowness et al (2007) were used to determine track movements during train passage along a run of 14 sleepers up to the crossing as shown in Figure 5. The geophones were placed on 7 alternate sleepers from the termination of the third rail on the approach to the crossing.…”

“…Figure 7 shows that the track displaces approximately 0.8 mm; data obtained by the University of Southampton from a variety of sites indicate that displacements between 0.5 mm and 2 mm are typical in the UK for ballasted plain line track in serviceable condition. Further details of the first use and development of geophone methods for measuring track movements can be found in Bowness et al, (2007). …”

“…In addition to geophone measurements of track movements, the University of Southampton has developed a system based on digital image correlation (DIC) to measure the movements of sleepers as trains pass directly (Bowness et al, 2005, andBowness et al, 2007). Since the details of this system were first published in 2005, the capabilities of digital cameras for the same or less cost have improved dramatically.…”

Determination of the primary technical parameters of the test bench for controlling the temperature of rails and rail bars of continuous welded rail

“…However, during the operation, temperature variations cause considerable longitudinal forces and tensions in the rails. At present, there are numerous temperature monitoring and determination systems using a variety of non-destructive testing methods, each having both advantages and significant disadvantages [3][4][5][6][7][8].…”