Science April 13, 2013 Why Trains Stay On Tracks -Submitted by David Drumm (Nal), Guest Blogger Share this:TwitterRedditFacebookEmailLike this:Like Loading...
13 thoughts on “Why Trains Stay On Tracks”
Thanks, Nal, that was fun.
OS, he was all that but he also knew how to listen. Years and years ago I say an interview with Dr. Feynman and he said either an astronaut or a NASA engineer clued him into the O-ring problem during the hearings. He was friendly with many NASA and industry people and one evening during the hearings one of his buddies dropped by his home (as his buddies were wont to do) and mentioned that the elasticity of the O-rings was a matter of great concern to people working with the shuttle, that someone might want to explore that. So Feynman got some O-rings. From that interview I got the impression that there was a lot of info that the commission wasn’t being given.
Feynman said, either in that interview or in a different forum that he suspected that he was being put on the commission because “they” wanted an actual big-name scientist that the public knew and trusted on it to make a typical do-nothing, feel-good exercise look authoritative. He even brought that up with the person(s) attempting to recruit him. He was the only participant to write a minority opinion contradicting the majority and he had to fight to get it in the record.
The tapered wheels are self correcting…
… Kind of how the USA needs to become.
Originally, there were all kinds of track gauges, ranging from 4 feet to 6 feet. Different gauges created a problem when a car or coach had to go from one rail line to another. They eventually settled on a standard gauge of 4’8½” (1,435 mm). The The Pacific Railroad Act of 1862 was the first attempt at standardizing rail gauges nationally. Since then, there have been modifications to the original law. There are still exceptions, such as streetcars and special use tracks for transporting large wide loads, but those are for short haul only. Think spacecraft, large telescopes and dockside cranes.
Some narrow gauge trains still run, but are now mostly for excursion or sightseeing, such as the Durango and Silverton Railroad in Colorado, and the White Pass & Yukon Route Railroad, which crosses the US-Canadian border between Alaska and the Yukon Territory.
I wonder if that was the reason for going away from wide gauge track, the problem with the turning radius.
Think of the flanges as limiting devices. When the wheel runs out of room, or if the track is uneven, the flanges keep them from going over the edge of the track. In extremely high speed trains, flanges may be needed on both sides of the wheel, instead of just the inside. As Dr. Feynman points out, if the flanges rub the rails you will hear them squeal. In this video, the small curve radius exceeds the capability of the tapered wheels to stay on the track. If a train goes too fast around a tight curve, it may exceed the limits of the flanges as well and jump the tracks. It that happens, the result is always ugly. You first begin to hear flanges squealing at about 2:00 in the video.
I always thought it was the flanges.
Just learned something I didn’t know I didn’t know b/c I never asked the question. Interesting.
I have a couple of physicist friends who knew Feynman. They tell me he was not only the smartest person in the room, but also the funniest. He had the gift of being able to explain the most complex things in ways almost anyone could understand.
When he dropped that piece of space shuttle O-ring into a ice water, let it cold-soak for a few moments then demonstrated its lack of resilience, was a demonstration of his genius and ability to connect with non-scientists. In that moment, everyone in the room knew what happened to cause Challenger to blow up.
Great video clip! I learned something today!!
Feynman, is one of my all time idols.
He has an accent just like maiy faddah.
“Spinnin’ wheel got to go ’round …” – Blood, Sweat, and Tears
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