Water-Trak cuts stopping distance by up to 40%
Introduction:
Autumn testing conducted in 2021 and 2022 has already demonstrated the benefits of Water-Trak in enhancing braking performance. While the improvement in normal braking may seem modest at approximately 1%g, this translates into an impressive reduction of nearly 20% in stopping distance and returns deceleration values to pre-autumn levels. This article goes further than previous analysis, presenting the results of our investigation into full-service braking manoeuvres and demonstrating the substantial advantages of adding Water-Trak to conventional braking systems
Enhanced Deceleration in Full-Service Braking:
On rare occasions during autumn, we noticed that drivers sometimes used full-service braking as they tried to stop the train safely. This prompted us to explore the impact of Water-Trak under these demanding conditions. The results we obtained were truly extraordinary. Figure 1 shows a boxplot analysis of full-service braking decelerations, comparing a control group of Northern Class 319s with two trains equipped with Water-Trak. The control group exhibited a wide range of deceleration rates, varying from a high of 13.8%g to a worryingly low 0.8%g. On average, the control group achieved a deceleration rate just below 6%g. In stark contrast, the Water-Trak trains delivered deceleration rates ranging from 6.4%g to 12.8%g, with an impressive average of 9.5%g.
Figure 1: Full service braking comparison showing major uplift in Water-Trak braking performance
Significant Reduction in Stopping Distance:
Figure 2 provides a comparison of stopping distances between Water-Trak and the control group, starting from a speed of 100kph. The substantial increase in average deceleration achieved with Water-Trak translates to an astounding 40% reduction in stopping distance or the equivalent of more than three train lengths of a Class 319. The implications of this improvement for operational performance and safety could be transformational for the rail industry.
Figure 2: Comparison of stopping distance with and without Water-Trak
Unlocking the Full Potential of Water-Trak:
The question arises as to why the deceleration improvement with Water-Trak in full-service braking surpasses that of normal step 2 braking. We believe that step 2 braking imposes limitations on the maximum achievable deceleration, obscuring the true adhesion improvement that Water-Trak can deliver. The findings from our analysis of full-service braking manoeuvres show for the first time that Water-Trak, when combined with sanding and WSP, possesses the capability to deliver far greater braking performance than previously reported.
Conclusion:
Autumn testing in 2021 and 2022 has proved that Water-Trak can deliver better braking performance. The improvement in normal braking we have previously reported already translates into a significant reduction in stopping distance. However, it is in full-service braking where Water-Trak truly shines, giving substantial increases in deceleration and remarkable reductions in stopping distance. These findings shed light on the untapped potential of Water-Trak, with important implications for operational performance and safety in the rail industry.
