This 90# jointed rail rolled in 1921 was replaced with 115# CWR in 2011. My photos aren't clear enough to determine where it was rolled.
The oldest rail I have ever seen was in Rochester, MN, in 1998, on the old GGW running through the middle of town. You have to look closely to see the date - 1898, the year my grandfather was born. 100 years old and it's not even that worn. Doug
There was Back about twenty years ago, there was some 1890's dated rail from the GN found in a local lumber mill spur. I know some of it was saved. But the person who would know where it went has since passed away.
Interference fits have been used in manufacturing ever since it was determined that things expand when heated and contract when cooled. Steam engines were a prime instrument of interference fit. The tires that contain the flange on locomotive drivers are heated to expand them so that they can create a tight interference fit when the assembly is cooled to normal temperatures. The interference fit is also why locomotive engineers on steam engines use the independent brake sparingly so the don't heat the tires to a temperature where they expand and have the potential to leave proper alignment on the wheel - it has happened. Like anything manufactured, mistakes happen, try as the manufacturer might to prevent the mistakes. Suspect the car builder, buys the assembled wheelsets from a supplier with wheels and bearings already installed and ready to be placed in the truck frames.
Yep, I have built a few traction motor assembly's. I am well aware of interference fit, we used electricity to heat the bearings and so forth to install them it was amazing how well it worked. You dont have to be off by much to have it all go wrong. Glad I transferred into engine service, it was more fun for me to wear them out than fix them.
I cannot speak to assemblies of today, but back when I was doing such work, trucks came in 'kit' form. Gondolas full of wheels, others full of axles. Boxcars with crates of springs. Etc, etc. Some parts were made on site, in the foundry. Side bearings, kingpins. Other parts were cut on gang torches.
Another of the Springfield derailment: Watching the cars derail, it looks like before they reach the crossing, there is a bit of a bounce occurring. And the cars seem to still be on rails before that. Possibly a soft spot in the roadbed?
One thing to remember, the NTSB speaker slightly understated the situation with the detectors, she said the train went by 3 detectors, but if you consider that the car has been going by defect detectors for years, 1000's of detectors. It had no problems reported for years and then in the span of 2 or 3 detectors went from normal to complete failure. That's the issue with a roller bearing failure, once it starts to fail it goes quick.
It was known to be "trending". Should have just told the crew to stop and set the car out. Yes, I know, we can all "Monday Morning Quarterback" now...
Was the 'trending' identified BEFORE or AFTER the train got the Critical Alarm from the 3rd Defect Detector? If before, how much BEFORE the train got to and passed over the 3rd Defect Detector. I smell a lot of after the fact CYA.
I would have to search, but I recall the HBD trended higher for 2 detectors earlier. That's still only about an hour or so, not a significant span of time to complete failure.
You have to have at least 2 points for a trend. They only mention 3 detectors. The first detector, 38 degrees, was "normal" or at least low enough there was nothing to cause any concern. The second point was 103 degrees, warming up, but well below the warning threshold of 170 degrees. You can touch 103 degrees with your hand, hot tap water is between 120 and 140 degrees. The third detector was 253 degrees, but that's not what the temperature was. According to an NS signal person on another forum, 253 degrees is the top temperature the detector will record. Since the train went in emergency immediately after the warning, the actual temperature was probably in the thousands of degrees, not hundreds of degrees, and the car could have been derailed at the time it went by the third detector. The question is how fast do bearings heat up and NOT fail? Maybe a 65 degree increase is not that unusual. if a train has been going slow and then speeds up, the bearing will naturally warm up as the car moves faster. If you start your car in the winter, the engine will be cold. After you drive it 20 miles the engine will warm up. You don't take it to the shop because you drove the car 20 miles and the engine temp went from 38 to 103 degrees.
On my former employer, if we got a trending alert from the dispatcher it was to set the car out, regardless of what a visual and physical inspection revealed. I have seen 2 different sources cited that the crew had been advised of the trending prior to the derailment. If true, that info will come out eventually.
