How does a train stay on tracks? - It's not the flanges!

A train stay on track because the wheels are tapered. The flanges are there for safety only and have little to do with keeping the train on the track. I would never have thought of that!

Watch and learn:tb-cool:
[ame="http://www.youtube.com/watch?v=y7h4OtFDnYE"]YouTube - Feynman and the Train[/ame]

 

Who is Feynman, what's his profession, and what Fraternity was he referring to?

 

In theory it sounds good, but if the flanges don't do anything and they are there only for safety then explain why the flanges are always shiny on a moving train. If they where not rubbing on the rail then they would be covered with rust. Since the flanges are rubbing the rails then the theory that the tapered wheel keeps the train on the rails does not work. This theory may work on straight track, but on curves and in turnouts I don't think so.

If someone else has proof of the theory, the tapered wheel keeps the train on the rails please explain the shiny flanges.

Gary

 

Gravity is the biggest thing keeping a train on the rail. It's the rail's job to keep the train above ground. Flanges are usually shined because of curves. A train naturally goes toward the outside of a curve. Hunting is a big factor also.

 

this is who he is (i think)

DR. RICHARD P. FEYNMAN
(1918-1988)
Nobelist Physicist, teacher, storyteller, bongo player

the hero of physics geeks everywhere!

 

According to the info In Wikipedia, Yes, that is he...http://en.wikipedia.org/wiki/Richard_Feynman Bob C.

 

Very true. Likewise...if wheel taper is all that keeps a train on the track...why would we need flange greasers in curves? The ideal is probably that the flanges don't rub much but the reality is that they do.

 

Doesn't a wheel roll on the flanges on the gaps in a turnout frog? Admittedly it's only for a brief moment when the wheel passes over the crossing rail.

 

Nope... have a look -> http://video.google.com/videoplay?docid=2853660703765713140

Although this is about a model turnout frog (and how it should work) it does show how the 1:1 scale version works.

 

Hmmm...okay. I buy that. I probably had the real one and the model one confused. :confused7xq:

 

Very interesting, thank you.

 

The video I posted only shows the working of the frog.
Let’s not forget the importance of the guide rails that keep the wheel from sliding into the gap by means of the wheel flange.

I would also think that even if the rails on both sides of the frog where not even the wheels would ride up onto the rail and not bang into it because the wheels are tapered.

Suspension is of course also crucial.

 

Feynman was a Nobel Prize winning physicist. Unfortunately, he died of cancer a little over 20 years ago.

The flanges aren't always in use. If they were, trains would always make that horrible grinding noise that they make in tight curves (when the flanges are definitely needed).

Feynman is (was?) no unschooled hack. Anyone who followed the investigation after the Challenger explosion will remember him as the scientist who asked the tough questions about NASA's own safety assumptions and who took a chunk of the troubled O-ring, stuck it in a glass of ice water, and then cracked it on the table to show how affected by temperature the material was.

If you listen to what he says carefully, he doesn't claim that flanges are useless, just that they are the secondary means to keeping the train on the track through the curves. If you were to take a solid axles wheel set and remove the taper completely I think you'd see a lot more derailments in curves, even with the flanges.

 

There are "flange-bearing" crossings, where one side (route) lifts the wheel slightly as it hits the cross line. The cross line is usually restricted to 10 MPH, because there are essentially "bumps" when crossing the main route.

 

Hi! I'm a newbie in here!
I have always admired trains, but I never took the time to understand how they work. The other day I read about this in one of Feynman's books (Richard Feynman is great!), and since then I've been thinking about what keeps a train on its tracks. The fact is, I don't know more about trains then I know about space rockets (I'd even say rocket science is a bit easier).

I watched Feynman's video on youtube, but as I don't know exactly what parts compose a train, I can't quite understand. I made a search on the web but I couldn't find good material for learning this. I wonder if anyone could indicate me a book or website so I can take a look at all the mechanical parts of a train. Thank you!
cool:
(and maybe I can post the answer when I get it!)

 

I'm not quite sure what you mean by "what parts compose a train".
By G.C.O.R. Glossary definition a train is....

"One or more engines coupled,with or without cars,displaying a marker, and authorized to operate on a main track.A term that when used in connection with speed restrictions,flag protection,and the observance or all signals and signal rules also applies to engines."

What that last part essentially means is that a locomotive or locomotives can be called a "train" when observing all those referenced rules,protections,restrictions and signals.

You can probably find any number of books from most railroad book publishers and sellers which will show you the mechanical parts of steam and diesel locomotives and types of cars and their mechanical equipment,ie brakes,wheels,sideframes,suspension,draft gear etc.

I wish you a hearty welcome to Trainboard! Please feel free to ask me questions either on the board or by private message. I am a retired locomotive engineer and I will try to answer your questions in a timely manner. I also invite you to read the thread I contribute to entitled "Storytime with Charlie" on the "Railfanning Discussions" board.

Charlie

 

The taper on the wheels is important and generally keeps the wheels centered on the rails. However that taper is only good up to about a 5 Degree curve. Anything over that relies on the flanges to keep everything on the rails. I'm not sure where I read or heard this so I can't back it up. I have watched Feynman's interview all the way through and like his approach on most things. However he uses the railroads as an interesting story. Anybody not in the industry or hobby it sounds plausible. To us though we question it because we have seen differently. Feynman was not a Railroad Physicist.

 

"Look, Ma! No Flanges!"



Hey, if they're on the wheels, they're probably important.