A good measure of the wheel condition is to compute the ratio of mean to peak load and express this as a simple number. Anything above a ratio of two is noteworthy and is passed to train maintainers, and anything above five is an emergency, which sees the train stopped as soon as it is safe to do so. This information, combined with analysis of the wheel data, has allowed Metro-North to instigate a wheel management system that allows wheel flats to be measured early and then to track the condition of any wheel damage over time.
The WheelChex system, powered by Vortok sensors, has been so reliable for Metro-North that the company, in partnership with Long-Island Railroad, put out a Request for Proposal for the construction and delivery of three ‘Train Fault Detector’ (TFD) houses to build on the original implementation, adding hot wheel and bearing detection, along with enhanced data analysis. Vortok International won this contract and combined the existing WheelChex technology with Progress Rail’s hot bearing and wheel detection systems to create a ‘first’ in the US rail transit industry in combining these measurements into one location.
This innovative TFD system provides a comprehensive overview of wheel and axle condition and will allow the railroads to benefit from operational information in the form of messages and alerts to tell them if a particular vehicle is presenting a risk to the infrastructure. With new trending algorithms it will be possible to plan ahead and avoid some of the panic that happens when the leaves fall in autumn, when most wheel damage occurs.
Innovation in this sector has led to solutions that not only overcome the original, obvious problems, like wheel flats in autumn, but also tackle complex issues such as hot wheel and bearing detection. With statistical data from the TFD, the railroads will also be in a stronger position to plan material purchases and benefit from better pricing and lead times. It will be exciting to see where this technology goes from here.