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A rail is a horizontally extending steel bar between supports that serves as a track for trains, automobiles, and other vehicles.
Types of Rails
There are three types of rails:
- Double-headed rails
- Bull-headed rails
- Flat-footed rails
1. Double-Headed rails
These rails were used in the early stages of railroad development. They are divided into three sections:
- Upper table
- Lower table
The upper and lower tables were identical, and they were introduced in the hopes of doubling the rail's lifespan. When the upper table wears out, the rails can be placed on the chair upside down and reversed, allowing the lower table to be used.
However, this plan quickly proved to be incorrect since the continuous contact of the lower table with the chair caused the lower table's surface to become rough, making smooth train operation impossible. As a result, this type of rail is almost obsolete. These rails are now available in lengths ranging from 20 to 24 feet.
2. Bull-Headed rails
This type of rail is made up of three pieces:
- The head
- The web
- The foot
Steel was used to construct these rails. The head is larger than the foot, and the foot holds the wooden keys that fasten the rails in place.
As a result, the foot's sole purpose is to provide the required strength and rigidity to rails.
When these rails are used, two cast iron chairs are required for each sleeper. Their weight ranges from 85 to 95 pounds, and they can grow up to 60 feet long.
3. Flat-footed rails
These rails were first invented in 1836 by Charles Vignoles, and so are also known as Vignols rails. They are divided into three sections:
- The head
- The web
- The foot
This type of rail has grown in popularity to the point where it now makes up over 90% of all railway lines in the world.
The benefits of flat-footed rails are as follows:
- They don't require a chair and can be spiked or keyed to the sleepers directly.
- They are thus cost-effective. They're less expensive than bull-headed rails.
- Both vertically and laterally, they are substantially stiffer; for curves, lateral rigidity is crucial.
- They are less prone to kinking and have a more consistent top surface than bull-headed rails.
The weights from train wheels are distributed over a large number of sleepers and hence a broader area, resulting in increased track stability, longer rail and sleeper life, lower maintenance costs, less rail failure, and fewer traffic delays.
Wear is defined as the abrasion or cutting of rail owing to friction and abnormally high loads.
There are three different types of rail wear:
- Wear on the top of the rails
- Wear on the head of the rails at the end of the rails
- Wear on the side of the rails' head
Rail Wear Reduction Techniques
To reduce rail wear, the following procedures are used:
- Use of special alloy steel proper track maintenance expansion gap reduction
- On curves, the inner and outer rails are exchanged
- Using lubricant oil
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