How do trains take turn.... does it have any differntial kind of mechanism?

Question

How do trains take turn.... does it have any differntial kind of mechanism?

Answer 1

All axles on railroad equitment are solid the diamiter of the wheel increases fro the flanged side to the none flanged which changes the wheels raduis around turns reduceing the stress's. I've been a pit man for 8 yrs. for the Termanil Rail Road and have yet to see a dirrernial of any kind EMD, SD, FP, EP,Alco, or other wise

Answer 2

Tom is partially right, the tapered profile of the wheels allow a n amount of "non-slip" turning, but the wheels turn at the same rate.  The outside wheel is on a larger diameter than the inside wheel, thus on one rotation, the outside wheel moves farther.

Hoghead is partially right.  The trucks, or bogies, on late model locomotives allow the axles to move so that each may align with the curve, but the wheels are still on rigid axles and must rely on the tapered profile to allow non-slip action.

However, there are limits to the allowable displacement, and, railroads may run wheels past the point at which the tread is hollow, and no natural steering may occur. Or some curves are simply to sharp.

The squeeling sound is usually the flanges scraping against the outside rail.  On most sever curves lubrication is used to relive the stress.

But invariably, something will wear, and derailments will occur again.

Answer 3

I take it you are comparing a train to an automobile. They are two different things. The reason you need a differential on cars and trucks is because the radical nature of their turns needs some way to relieve the stress. A railroad trains wheels are independent from each other so that there is no place for the stress of turning to build. Though the axles are straight under them the wheels turn independently. Locomotive drives are built so that one side can always move ahead of the other (go faster, turn higher RPM) when they need to. This goes for both forward and reverse drive.

Answer 4

no they dont., they dont turn sharp enough

Answer 5

There is no differential on the axles - they are solid. As Tom-SJ's answer states, the wheel's are tapered, and that helps facilitate negotiation of the curves.

Answer 6

Obviously, trains run on tracks.  But since the wheels are fully attached to solid axles,  wheel slippage does occur when taking curves.   You can tell this happens when you hear high-pitched metal-on-metal squealing as a train rounds a sharp curve.

There are two other features about rails and wheels that permit wheel slippage.  First, the inside shoulder of the each rail is not  sharp, instead it has a rolled edge profile.  Second, the wheel itself is not flat, but it has a slight tapered profile - a wider diameter at the flange and a narrower diameter at the outside / non-flanged side.  These two features allow each wheel on an axle to turn at a different speed - when making a turn, the outside wheel turns faster while the inside wheel turns a bit slower.

Over time, as the rail and wheels wear,  the rail profiles must be re-ground to a new rounded profile with a special rail profile grinding machine.  And the wheels may need to be re-profiled on wheel turning lathes.

Answer 7

.................... they don't turn ...... pal ...... they only follow the track ........ the tracks are gradually turned in a gentle ark .........

Answer 8

very gradually. all rail corners are very gradual to allow the steel wheels to "slip" a small amount as the train rides around it, thus no differential is required.

Answer 9

There is a lever they use to control that, im not a conductor so i cant really answer the question with positive answer. sorry :(

Answer 10

Though still unequipped with a differential, newer EMD AC engines have a system by which the drivers can "track" when negotiating a turn, resulting in less slip, which allows for better traction.

I'm confused by the answer above relating to turning radius.  The curve at Cantara Loop is a 15 degree curve and the locomotives traverse it every day.  It has been problematic, however, since there have been three major derailments there, including the big one that killed all aquatic life in the upper Sacramento River, between Cantara Loop and Lake Shasta, some 30 miles of river.

It's going to happen again, too.  The trains are too heavy and too long for road bed constructed in 1880.

Answer 11

They follow the rails. There are switches where short segments of rail move to control which track a train takes. The train itself does not have controls for steering.

Answer 12

hi all there is no slipping of wheels on a curve. this is due to the shape of the wheels, on a curve the smaller side will be the inside and larger diameter on the outside.

steam train driver, south africa

bruce