In the early days of the railroad, Train rails were made of either cast iron or wrought iron. Cast iron was too brittle and would break easily. Wrought iron was too soft and would wear out too quickly. So steel eventually became and remained The train-rail metal of choice. The train wheel's rim runs on the inside of the rail To keep the train on the track. This plant makes train rails entirely out of recycled steel From scrapyards, food cans, And recycled pieces from the rail-making process itself. Electromagnets pick up the scrap And dump it in a charging bucket.
A truck hauls the bucket inside, Where a crane drops the contents into a furnace. An intense electric current Melts the scrap steel at 3,000 degrees fahrenheit. It then flows into a large brick-lined ladle, Where they add carbon, manganese, and other elements To make the steel more durable. The alloy then runs down a ceramic tube That shields it from exposure to oxygen, Which would ruin the metal. From there, the molten metal flows into molds,
Which extrude it into continuous rectangular blocks Called blooms. Acetylene torches cut each bloom into 12-foot lengths. A crane then transfers the blooms to a furnace, Which, over the next five to seven hours, Reheats them to 2,300 degrees fahrenheit.
This softens the steel for further shaping. Then the reheated blooms enter a machine called a rolling mill, Which elongates each bloom, more than quadrupling its length. A shear then slices the longer, thinner blooms into four pieces. The pieces now go into another furnace for reheating. This preps them for the next set of rolling mills, Which will gradually form them to the final rail shape. Different railroads used to use different-shaped rails, Which required changing the train's wheels When passing from one railway to another. By the turn of the 20th century, The t-shaped rail became the industry standard And remains so today.
For the final shaping, each steel rail Passes several times through three consecutive mills. This is what a mill's rollers look like. And here's the standard "t" shape To which they form the steel. Next, a saw slices off about 12 inches to square off the ends. The cut-off pieces go back to the scrapyard. The rails, meanwhile, are laid out Until they cool to about 930 degrees fahrenheit. Then an electromagnet piles them in a holding box, Where they sit for 10 hours Until they cool off to about 190 degrees fahrenheit. When they come out of the box, They run through two sets of rollers.
The first set flexes the rail vertically. The second, horizontally. This flexing process Straightens out the rails, which curve slightly Due to all that heating, shaping, and cooling. Next, each rail passes over a mirror, Enabling inspectors to examine the bottom, as well as the top. Finally, a saw cuts the rails To whatever size the railway ordered -- Most often the standard length of 82 feet. The quality-control department measures random samples
To make sure all the dimensions are precise. Every rail bears a number Identifying the batch of steel from which it came. In the event of a problem, that number Lets them trace all the rails made from the same batch. It's a system that ensures a safe, smooth ride.
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