History of Train
Types of Railroad
How Railroad Works
Riding the Rails
Super Speed Train
How Railroad Works
Rails are made of high-grade steel and often weigh between 112 to 145 pounds per yard. They can stand the weight of 75,000 pounds per square inch! Rails were and sometimes still are manufactured at 39' long. These sections are bolted together. On long distances, rails are welded together for a smoother ride. This type of rail is sometimes called ribbon rail or the slang term "velvet."
The rails are 4' 8½" apart. The distance is called "gauge" or "standard gauge." Because almost all railroads in North America are "standard gauge," a railroad car can travel anywhere there is a railroad. This gauge was first used on track to experiment with the first steam locomotives in England. It became the predominant gauge in the United States when President Lincoln ordered the first transcontinental built at 4' 8 ½". The railroads themselves proclaimed it the nation's standard in 1886.
Rails are held together by ties. Most ties are made of treated wood, cement, and sometimes steel. The rails are held on ties with spikes and an undercarriage called the tie plate. Railroads also now use a spring clamp device to hold the rail rather than plates and spikes in heavy traffic areas. The clamps and spikes keep the rails from moving outward as the weight of the train keeps them on the ties.
Ballast is needed under and between the ties. A bed of crushed rock keeps the track higher than the surrounding landscape. It also provides a smoother ride and helps drain rain from the track.
Tracks are often "superelevated" on curves. Superelevation is the making of the outside rail on a curve higher than the inside one. The superelevation permits trains to negotiate the curve more safely at a higher speed.
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