hi every body<i want to know about a train wheel and how the flange of the wheel holds the train in the track and avoids derailment?
Interesting questioin. The flanged wheel has been called one of the greatest inventions of mankind. As stated above the flanges are on the inside of each wheel and rub against a wear surface of the rail. In other words, each wheel is responsible for one half of the forces required for keeping the train on track. The width (guage) of the rail is absolutely critical in keeping things operating. Amazing system when you consider it, the flange is not much higher than the width of your thumb, the actual contact patch of a wheel on rail is about the size of a dime. That gives you a bit of an idea why trains are so much more efficient than any other type of land based transportation.
Train Wheels. While seeming simple, you really opened up a real can of of scientific worms. Two wheels joined on an axle. The flange is on the inside of the wheel and sits below the track. As the train moves, the lowest part of the wheel on the flange actually moves in the opposite direction of train travel. Ideally, the flange should never touch the track. The flat part of the wheel that rides on the track is called the TYRE. The tyre as well as the track it self are tapered. That is to say they are conically shaped. The weight of the car sitting on a tapered rail, as well as wheel helps to center the car and steer it though curves. If the wheel would lose its taper, then the car would shake back and fourth (hunt) as it rolled down the track trying to center itself.
Both wheels have their flanges inside of the rail, so both flanges together maintain the car at its place, one preventing it to slide on left, the other preventing to slide on right. The secret that prevent flanges runing over the rails is weight, so you can assume that if a train was running on moon, it would need longer flanges. Switches are built so they allow one of the flanges to slide from a rail to another while clearing the for other wheel's flange.
