Have you ever been on a train? When you get settle into the seat in the train carriage, you have a fast and smooth ride. Have you ever wondered how it is you get such a smooth ride? It is not bumpy at all like when you are in a car or bus.
Tramway tracks have been in existence since the mid-16th century. The rails for the trains were first made from wood then they were made from iron and then steel and a mix of both iron and steel.
There were obvious flaws in wooden rails. They splintered and rotted and had to be replaced often. Iron was then used to make the rails, and much trouble was taken to remove the wooden tracks to lay the iron rails; but within 20 years of their introduction, their flaws began to show.
Iron is quite brittle. The iron rails started to break as the trams and streetcars got heavier. As the vehicles got larger and faster, the rails needed to be replaced as often as every three months! This was very expensive and took a lot of time that disrupted the routes that people took – it just was not very satisfactory all round. Public demand for faster transport made the inventers think about what they could do about it. Sure, they made faster engines, but without proper and safer tracks, faster engines just would not work.
In Europe, the officials considered making the rails out of steel or a mix of steel and iron. Making them out of just steel was very expensive so if they mixed the two metals, it would be a bit cheaper to produce.
“The first steel rail in the world was made in England in the mid-1850s, and a trial installation on a railroad was made in 1862. After two years, officials found that it had outlasted the eighteenth replacement of adjoining iron rails.”
How do they make steel?
“There are two types of metals, ferrous & non-ferrous. Ferrous comes from (or contains) iron, (mild steel, cast iron, high strength steel, and tool steels) while Non-Ferrous does not contain iron (copper, aluminium, magnesium, titanium).”
To make steel, iron ore is first mined from the ground before it is smelted in blast furnaces where the impurities are removed and carbon is added. Blast furnaces are huge steel shells almost cylindrical in shape and lined with heat-resistant brick. Iron ore and other iron bearing materials, are put into the furnace from the top and slow melts down lower and lower becoming hotter as they sink down into the body of the furnace. “In the top half of the furnace, gas from burning coke removes a great deal of oxygen from the iron ore. About halfway down, limestone begins to react with impurities in the ore and the coke to form a slag.”
At the bottom of the furnace, the temperature gets very, very high and a huge puddle of melted stuff called “molten slag” floats on a pool of molten iron; the workers then drain off the melted iron on the bottom through a tap hole. This melted iron then gets poured into moulds. The moulds are long and thin in the shape of rails. The rails are then transported to where the workers will make the railways. The long iron rails are placed on top of thick wooden “sleepers”; the wooden sleepers are laid on gravel beds.
When making steel (called steel billet) into rails, a system called “rolling” is used to cool and straighten the steel that will be turned into strong rails for the train tracks. “Rolling” is the most important part of the process. The heavier the steel rail is per metre; the greater weight the rail can bear.
There are two methods used when rolling: groove rolling and universal rolling. Groove rolling is simpler than universal rolling, which is the most popular way used around the world.
Today technology is so good that the workers can inspect how good the steel rails are on the inside by using an ultrasound wave, eddy, and laser beam. China has studied the process of turning iron ore into steel and from the 1980s has been leading the field in this technology.
School children are often taken on school field trips to steel mills (places that make steel from scratch using the iron ore that is mined from the ground). Next time you travel on a train, remember to look at how the modern rail track is placed on the ground.
