What kind of steel is use to make railroad tracks?

Question

What kind of steel is use to make railroad tracks?

Answer 1

Very high-grade, prestressed steel which is designed to take both the weight and the friction of trains weighing hundreds or thousands of tons travelling over it.

It is rolled into shape at the steelworks, in lengths several hundred yards long which need special trains to take them to the construction site and lay the rail. The lengths of rail are welded together but every so often an 'expansion' joint is inserted to prevent the rail buckling under excessive heat. If the rail has been properly laid and properly maintained it will stand up to all the stresses and strains of heavy use, and last 20 years or more before it needs to be replaced.

Before the days of welded rail the lengths were about 60ft which is the average length of a passenger carriage and a gap of about 0.25" was left between each rail to allow for the expansion. This is what caused the 'clackety-clack' sound which is now virtually absent from railways today.

Special rail vehicles equipped with plasma rays are sent over each stretch of line from time to detect any hair line cracks which might appear in the rail which are invisible to the naked eye, but will show up on the scientific equipment. These cracks are rare but there is a slight chance they may happen and if found, the offending section of rail can be replaced before it becomes dangerous.

In earlier days, rails were made of the best quality steel that was available and when no longer fit for use, were often recycled and made into fence posts, supports for station awnings, and other light structures. In this form they can sometimes survive for many decades.

Answer 2

It's not any special steel by any means. It's just a common steel. Remember, steel wheels only roll on it. The quaility in the manufacturing has to be high though. Any small air pockets in the metal, or hair line cracks will over time cause a fracture. The only time heat is a factor is when the train brakes are applied. Heat is a critical component for the brakes to function. But only a very miniscule amount of this heat could ever be transferred to the rail. The rails just sit there and support a lot of weight, so common steel works just fine.

The size of a rail is measured in pounds per 3 feet (one yard). 70 pound rail (per yard) is fine for a branch line railroad that maybe has shorter trains at slower speeds. For the mile long trains of today, 130 pound rail is more suitable. I've seen small industrial railroads that were built of 30 pound rail.

This is the formula for the weight a rail can support, with ties properly spaced. A rail can support 300 times each pound weight per yard. So, a 60 pound rail can support 300 times 60, or 18,000 pounds per wheel, and 36,000 pounds per axle (18 tons). That means it can carry a car or engine no greater than 72 tons.

A quick analysis of 130 pound rail is it can support a car or engine no greater than 156 tons. Some engines weigh upwards of 220 tons, but their weight is spread out over six axles instead of four. And I don't know the forula for computing this part.

Answer 3

Derail and Rango are engineers.  And I can tell you with confidence that both of their answers are correct.

I am a member of a local train club.  I can only tell you this.

That Iron is really heavy!

Good Luck!

Answer 4

Above answer is somewhat correct, but odd as it seems it is not high carbon or hardened steel, far too brittle and subject to breaking. It is mild steel. Older U.S. steel was very good quality, the newer imported (Chinese) steel has had some very serious quality control issues.

As you may guess, in cold weather the rail is under a lot of stress, very taught, a flat spot the size of a 50 cent peice on a railcar wheel can cause breaks in the rail at 0 degrees or colder.

The first cold snap in the winter will find dozens of hidden defects in rail, the additional stress will cause it to break and pull apart. sometimes those gaps on a pull apart will be several feet long.

Rail can get rough much like a gravel road and occassionally needs resurfaced, they use highly specialized grinder trains that smooth and reshape the surfface of the rail.

Standard rails are 39 feet long, mostly because the original flat cars were 40' and that is the length early rail plants were set up for, newer welded rail is delivered in 1/4 mile increments, it is not installed with expansion joints, the rail is anchored solidly enough the that expansion is (theoretically) confined to vertical movement rather than horizontal and lateral.

Older bolted rails are still recycled, they are picked up, sent to a welding plant where the ends are cut off, they are magna-fluxed for defects and welded into CWR (continuous welded rail) and installed in sidings or lighter density lines.  

"Rail detector" cars are typically ran over a system several times a year looking for defects before the rail can break and cause derailments. It uses  magnaflux and ultra sound detection. I've never heard of a plasma detector, must be somethign new, interesting.

I was walking along a branch line near my house the other day, the rail was 100 lb. (meaning 100 pounds per yard),  dated early 1900's and is still in daily use.

Answer 5

rr track is hot rolled manganese steel

Answer 6

Most rails in the UK were made at Barrow in Furness steel works. If you look on the side of old rail systems you will see *Furness Steel* on them. When India was a British Empire country all the rail infrastructure was of Furness Steel and still is after all the years. A friend I know in India went to look when I told him and came back to me in amazement. He said that in all his years a a rail fanatic he had just learned something.