R Paul Carey wrote: ↑Fri Feb 24, 2023 9:36 am Woodeen is correct; there were three measured readings, with only the third at East Palestine indicating a "critical" above-ambient temperature on the defective car.Thats what I've been trying to say. The bearings just don't catastrophically fail, they are really no different from the wheel bearings in your car, and the signs of failures are similar. The wheel can break off your car as well if you let the bearings go too long.
Yesterday's NTSB release describes the temperature thresholds that, according to NS policy, describe the critical threshold at which the train must be stopped and the defective car must be set out.
The criteria for the maintenance and use of "hotbox detectors" have not been addressed as a matter for regulation, but rather it has been left to the individual railroads to establish the policies and practices for their operation. Yesterday's NTSB report appears to confirm that NS handled the three readings in accordance with its policy.
My belief is that speculation regarding electro-pneumatic braking and its benefit is based upon imperfect or mistaken assumptions as it applies to the facts of the EP incident.
Is it an unanswerable question, however, that the blazing bearing, on the 23rd car from the head end, could have been seen in the evening darkness on the inside of a curve, between Salem and East Palestine?
Since the criteria for operation of these detectors likely vary among the railroads, it would appear that the industry should promptly step up and prescribe "best practices" for HBDs, to include their maintenance and testing, thresholds and actions for readings that show a progressive increase of temperature between HBD locations and/or variation between the two bearings on a single axle.
It's not acceptable to maintain a policy that requires no action short of a "critical" reading, nor is it acceptable to assume that a "fast burn-off" is an acceptable risk of doing business as usual.
If the industry should fail to take action promptly, then the FRA should do it for them.
One main difference is your car is frequently inspected and they can feel the wheel getting loose. Most times you can hear the bad bearing in the car while driving as well and it can affect steering.
On a railroad car, you look for leaking grease and bad seals. The detectors used to be used in combination with car department forces, not to replace car department as is now done under PSR.
The conductor out there checking the bearing with a templestik was the last line of defense.