An education worth dying for.

Known unknowns and unknown unknowns!

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Harbal
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Re: An education worth dying for.

Post by Harbal » Sat Jun 03, 2017 6:33 am

thedoc wrote:
Sat Jun 03, 2017 2:27 am

Did you know that railroad wheels have a flange and a tapered tread, and the flange rarely touches the rail head. With a tapered thread the wheel centers itself on straight sections, and only on the sharpest curves does the flange touch the rail.
It's amazing what you can learn round here but I wouldn't call it an education to die for.

Walker
Posts: 5246
Joined: Thu Nov 05, 2015 12:00 am

Re: An education worth dying for.

Post by Walker » Sat Jun 03, 2017 11:58 am

Harbal wrote:
Sat Jun 03, 2017 6:33 am
thedoc wrote:
Sat Jun 03, 2017 2:27 am

Did you know that railroad wheels have a flange and a tapered tread, and the flange rarely touches the rail head. With a tapered thread the wheel centers itself on straight sections, and only on the sharpest curves does the flange touch the rail.
It's amazing what you can learn round here but I wouldn't call it an education to die for.
Feynman explains the tapered wheels on a video I once saw.

And when you think about it, a differential for each train axle coordinated by a computer system would be rather expensive for a freight train, although some engineer might come up with the idea for unknown reasons.

thedoc
Posts: 6441
Joined: Thu Aug 30, 2012 4:18 pm

Re: An education worth dying for.

Post by thedoc » Sat Jun 03, 2017 12:53 pm

Philosophy Explorer wrote:
Fri Jun 02, 2017 11:03 pm
Harbal wrote:
Fri Jun 02, 2017 10:59 pm
Philosophy Explorer wrote:
Fri Jun 02, 2017 10:52 pm

Did you know part of a flanged wheel is always moving backwards while the train moves forward?
Yes but did you know part of a flanged wheel is always moving forwards while the train moves backwards?
And did you know the top part of the wheel is moving faster than the bottom part of the wheel?

PhilX
Did you know that the one part of the wheel that is in contact with the rail (and the same applies to any wheel and surface) is stationary even if the rest of the train is moving?

thedoc
Posts: 6441
Joined: Thu Aug 30, 2012 4:18 pm

Re: An education worth dying for.

Post by thedoc » Sat Jun 03, 2017 1:04 pm

Walker wrote:
Sat Jun 03, 2017 11:58 am
Feynman explains the tapered wheels on a video I once saw.

And when you think about it, a differential for each train axle coordinated by a computer system would be rather expensive for a freight train, although some engineer might come up with the idea for unknown reasons.
And that is totally unnecessary because a tapered wheel does it automatically.

If you are watching a train and you hear the squeal, that is usually when a flange is in contact with the rail, and the thumping is usually a flat spot on the wheel from the brakes being applied and the wheel sliding on the rail.

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