Visual Indicators that Support Safety and Reduce Maintenance Costs
The safest railways in the world have two things in common: reliable power and rigorous maintenance. Of the two, maintenance is the fastest and easiest to improve, and may well have the quickest payback.
Better maintenance means fewer delays. When a rail car is taken out of service unexpectedly, delays ripple throughout the network. In Amtrak’s Northeast corridor alone, problems just with the rail cars caused 2,149 minutes (35.8 hours) of delays for its five rail lines during Q4 2022. In the UK, the ripple effect from one small incident in the south-central part of the country affected trains as far north as the Scottish border 20 hours later.
Far more serious, however, is the potential for train derailments. A derailment on the DC Metro in 2021 caused all 7000-series cars to be removed from service, resulting in limited service and months of delays. Last February’s derailment of a Norfolk Southern train in East Palestine, Ohio, however, released toxins into the air and water and shut down that portion of the line for about a week.
Accidents Linked to Overheated Bearings
The cause of the East Palestine derailment was entirely preventable, according to the preliminary report of the National Transportation Safety Board. “A wheel bearing failed,” NTSB Chair Jennifer Homendy said during a news conference.
Now, Norfolk Southern is adding 200 hot-box temperature sensors along its tracks to detect overheating bearings, and is accelerating development of next generation safety technology. It also just joined the Federal Railroad Administration’s (FRA’s) close call reporting system, which encourages rail workers to speak up if they see something unsafe.
The East Palestine accident brought home, painfully, the fact that bearings that overheat can cause train derailments. To detect these overheating components, approximately 6,000 hot-box detectors are installed every 25 miles along Class I freight railways, according to the FRA. Their presence has reduced accidents caused by axel and bearing issues by 59 percent since 1990.
Hot-box detectors work by scanning temperatures about four inches above the top of the rail and comparing them to either the temperature of the mating bearing on the same axel or to the ambient train temperature on that side of the track. Typically, alerts are issue by email, page, fax, WiFi or radio, which requires train operators to have the equipment to receive and act upon these alerts.
Relying on the railway’s hot-box detectors isn’t a complete solution to the problem, though. Hot-box sensors’ accuracy may be affected by misaligned scanners or proximity to track joints and switches, and the speed of the train. (Speeds between 10 and 100 mph are optimal.) They must be calibrated every three years.
Thermax® Temperature Indicators Add Extra Protection
Forward-thinking rail car owners (which often are private owners, including producers and banks) are adding an additional safeguard. They stick Thermax® temperature indicator labels to the axel box to accurately record temperatures that exceed predetermined thresholds.
Thermax® labels record the highest temperature reached by the label. Their temperature thresholds range from 29°C/84°F to 290°C/554°F, which is a significantly broader range than the FRA’s hotbox detectors.
Each indicator is composed of a series of sealed, phase-change temperature test labels. Therefore, when specific temperatures are reached, the relevant chemical material melts and is absorbed by the substrate, changing color from white to black, permanently.
These temperature indicators are designed to withstand the rigors of rail operation. They will not delaminate and they resist oil, water and steam, making them extremely durable. They are inexpensive, and, because the data are irreversible and accurate, they are reliable.
Installing Thermax® temperature indicators is fast and easy. Simple slap a self-adhesive label on the bearing box, and you’re done. That’s all there is to it.
It’s also extremely easy to read. Maintenance professionals can see any color changes at a glance, so they can determine whether wheel units need closer inspection or maintenance quickly and easily.
Thermax® temperature measurement strips are available in multiple shapes, sizes, and temperature ranges to accommodate various applications. They don’t tear, so they can be removed from the bearings easily and attached to inspection and maintenance reports as a permanent record.
Overheated bearings can cause major accidents and delays that affect communities, carriers and their clients for months. The costs can become substantial. Even if no accident occurs, taking rail cars out of service for unplanned maintenance can be disruptive.
Instead of relying upon scheduled maintenance or waiting for bearings to fail, predictive, preventive, and condition-based maintenance is the foundation for a robust maintenance program. In fact, condition-based maintenance can save between 5 and 12 percent of the life-cycle cost of a rail car. That’s only feasible, however, when you have deep insight into those conditions quickly and easily.
Thermas® delivers that insight, providing easily visible evidence when overheating occurs. Such early insights help rail car owners take proactive, preventive action, so incidents can be averted.
How SpotSee Can Help
Rail car safety is top of mind now, with the aftermath of the East Palestine, Ohio derailment destined to remain in the news cycle for the foreseeable future. Simple steps to improve maintenance and, therefore, safety, go a long way towards ensuring the safety and reliability of your rail network now and in the future.
Contact SpotSee to see how Thermax® temperature indicators can help you improve your rail car safety program.