track

[Anonymous]

everytime i look at how railroad track is put together, i am amazed that a train stays on. where can i read about the physics and dynamics of how and why this works-

[Anonymous]

I will probably need more help with this. But for starters, the railroad cars wheels run along the inside of the track, keeping the cars from going left or right. Second, the railroad cars wheels have a groove (for lack of a better word) which matches the groove of the railroad track.

That's it! Hopefully somebody has a better word for groove.

[Anonymous]

If you take a good look at the railroad track, you will notice that a lot of track's top inside groove (for lack of a better word) is worn.....

[edblysard]

The physics are simple. The cars and locomotive weigh so much, and the wheels have a flange on the inside,about 1 inch tall, which holds the wheels on the track. The rail head, or ball of the rail is slightly rounded, and the contour of the wheels is slightly tapered, from the inside flange to the outside of the wheel, with the taper becoming more sever the closer it comes to the outside. this helps center the truck on the tracks. Because everything weighs so much, it isnt even necessary to "bolt" the trucks to the cars, they ride on a bolster pin, nothing more. Even small switch motors weigh more that you would think. We use MK1500 D's here at the port, and they weigh 254 thousand pounds each. Thats 125 tons. Short of hitting another locomotive, not much is going to make it jump off the rail. And all that weight is riding on a surface about the size of a quarter, thats the contact surface of a wheel on the rail. All the weight of the locomotive and cars is transfered from the ball of the rail, down the web, the thin part, to the foot, which is about twice as wide as the rail head. And the rail itself is very heavy, about 135 to 155 lbs per yard. Steel rail dosnt twist easily, and all of this sits on a steel tie plate, with a grove the width of the rails foot, which it rail sits in, all held down by spikes, or pandrol clips if you have steel or concrete ties. All the spikes or clips do is keep the rail from moving sidewawy. Because all the weight is concentrated into a small areas, and it is spread out over eight or twelve wheels, and further dispered by the ties to the roadbed, the only real impact you have to worry about is sideways, or centrifigual force, which is handled by raising the outside rail, or superelevating the rail, causing the dynamic forces to travel downward, instead of sideways, just like taking a banked turn in your car, the centrifigual force holds the train to the track.
Stay Frosty,
Ed

[sooblue]

Hey Ed,
Were can I get a view of a concrete tie and pandrol clips?
I need the Specs. too.
Sooblue

[edblysard]

Hi Blue,
try
http://www.railway-technology.com/contractors/rail/index.html
Whew...pretty much everything you need to lay track, click on the pandrol link, and the first thing you get is a nice photo of one on a concrete tie or sleeper.
Have fun,
Ed

[edblysard]

Forgot, try this one for rail specs.
http://www.com/atlantictrack.com/alt_search.cfm.
Ed

[Soo2610]

Nice explanation!

[wabash1]

Hey Ed, With exsplaining like that someone is going to think you are not a conductor. Us people in railroading all know the job of the conductor is to keep the paperwork from blowing out the window... have a safe friday Ed later.

[sooblue]

Hi Ed,
You know I forgot that all you have to do is type in what you want and bamb! you got it.
Thanks. I had a request from a small gauge RR to make some concrete ties for them so I need to become an expert fast.
Sooblue

[edblysard]

We just put it under the engineer, with that much "weight on the drivers", it aint going anywhere....
You be safe too, hope its as great outside there as it has been for us.
Stay Frosty,
Ed

[wabash1]

that is the second copy of paper work for when you guys lose the first you still have a copy. the weather has been great here to bad i been working on my rest to enjoy it. But with the wind in my hair hanging out the cab window. ( yes engineers still have some hair) i wouldnt have it any other way.

[edblysard]

And they pay us to do this. What a country!!!
Stay Frosty,
Ed

[wabash1]

you mean you accept a pay check, heck i thought it was a crime to have fun at work and get paid so i do it for nothing.

[edblysard]

Ok, now let me check my leg, and see how far it's been pulled....feel kinda sorry for the 9 to 5er's, you just cant beat watching the moon come up every night, or seeing owls fly by, hunting for their dinner. We even have a family of foxes living up on the hill, they come down in the yard every once in a while.
Stay Frosty,
Ed