What is a Railway Sleeper? Uses and Classification

What is a Railway Sleeper?

Components on which rails are arranged in a proper gauge is known as railway sleeper. Railway sleepers are also called crossties, railway ties, and railroad ties. These sleepers rest on the track ballast. Ballast is the foundation of railway track to hold the sleepers in position during the train’s passage and transmit and distribute the load from the sleepers. Ballast is also used to provide lateral stability to the track.

Railway Sleepers

Uses of Railway Sleepers

  • Transfer the load from rails to the ballast and ground.
  • To hold the rails in a proper gauge.
  • Provides an elastic medium between the ballast and rails.
  • Reduce vibrations during the passage of the train.

Classification of Railway Sleepers

  • Wooden Sleepers
  • Steel Sleepers
  • Cast Iron Sleepers
  • Concrete Sleepers
  • Composite Sleepers

 

Wooden Sleepers

It is a kind of railway sleeper that is made of wood is known as timber sleeper or wooden railway sleeper or wood railroad tie. These are now backdated and not used widely.

Wooden Sleepers

     Advantages of Wooden Sleepers

  • The initial cost of a wooden sleeper is low.
  • Suitable for tracks in coastal areas and salty regions.
  • Timber is a good insulator, therefore suitable for track circuiting.
  • Timber is easily available.
  • Wooden sleeper is the cheapest of all sleepers.
  • Easy installation of fasteners in the wooden sleeper.
  • In case of a derailment, wooden sleepers are not badly damaged.
  • More useful for high speeds and heavy loads.
  • Manufacturing is easy.
  • Renewable of track and sleeper is easy.

     Disadvantages of Wooden Sleepers

  • Life is very less as compare to others.
  • Difficult in maintaining gauge of the track.
  • The scrap value of the wooden sleeper is very low.
  • Creep resistance is poor.
  • Catch fire easily.
  • Affected by dry and wet decay.
  • Possibility of humidity and vermin attack.

 

Steel Sleepers

Sleepers made of steel are called steel sleepers. Steel sleepers are subjected to medium and heavy axle loads and used for standard railway tracks.

Steel Sleepers    Y steel sleepers

     Advantages of Steel Sleepers

  • Light in weight, hence it is easy to handle.
  • Dimensionally more reliable than concrete or wooden sleepers.
  • Good resistance against fire and creep.
  • No chance for vermin attack.
  • The scrap value is high.
  • The connection between sleeper and rail is simple and stronger.
  • Lateral rigidity is better.
  • Life span is good.

     Disadvantages of Steel Sleepers

  • Not suitable for all types of ballast, gauges, and rail sections.
  • Not suitable for bridges and level crossing.
  • In case of a derailment, steel sleepers are badly damaged.
  • Require more quantity of ballast.
  • Require high maintenance and more fittings.
  • Liable to corrosion due to moisture.
  • Should not use in the salty region.

 

Cast Iron Sleepers

Cast iron sleeper is made up of cast iron. This type of sleeper is extensively used in India as compared to other countries. Curves sharper than 4 degrees are not suitable for pot-type sleepers.

Cast iron sleepers

     Advantages of Cast Iron Sleepers

  • The maintenance is low.
  • More durable, hence life span is more than 60 years.
  • Rail creep can be prevented.
  • No chance for vermin attack.
  • Manufacturing is easy and can be done locally, therefore no need for longer transportation.
  • High scrap value and can be remoulded.
  • Provide sufficient bearing area.
  • The probability of cracking at the rail seat is low.
  • Less corrosion as compare to steel sleepers.

     Disadvantages of Cast Iron Sleepers

  • In case of a derailment, steel sleepers are badly damaged.
  • The shock absorber is low.
  • A large number of fastening materials are required.
  • Cast iron is expensive as compared to other sleeper materials.
  • Not suitable for coastal regions because it is easily damaged and corroded by saltwater.
  • Not suitable for all types of ballast.

 

Concrete Sleepers

Concrete sleepers are made up of steel-reinforced and prestressed cement concrete. This type of sleeper is now replacing all other types of sleepers except crossing bridges.

Concrete sleepers

     Advantages of Concrete Sleepers

  • High stability and less maintenance.
  • Suitable for welded tracks.
  • Give better lateral stability to the track because it is heavier than all types of sleepers.
  • Good insulator therefore suitable for track circuited tracks.
  • No chance for corrosion.
  • Low maintenance cost.
  • Good fire resistance.
  • Long life span.
  • No chance for vermin attack.
  • Suitable for all types of soil and moisture conditions.

     Disadvantages of Concrete Sleepers

  • Handling is difficult due to heavyweight.
  • Concrete sleepers are not suitable for crossings and bridges.
  • The scrap value is nil.
  • The initial cost is high.
  • Liable to crack due to shrinkage and creep.

 

Composite Sleepers

Composite sleepers are sleepers made up of continuous glass fibre reinforced polyurethane foam. The shape of the composite sleepers is similar to ordinary wooden sleepers.

Composite sleepers

     Advantages of Composite Sleepers

  • Light in weight.
  • Great in strength.
  • Eco-friendly sleepers.
  • Reduce vibrations during the passage of the train.
  • Composite sleepers are recyclable therefore its scrap value is good.
  • Life span is good, more than about 50 years.
  • Reused for any type of rail section because it can be resized easily.

     Disadvantages of Composite Sleepers

  • Not that much good against fire.
  • Limited design flexibility.
  • Composite sleepers are temperature sensitive.
  • Strength and stiffness are low.

 

 

 

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  1. July 12, 2021

    […] What is a Railway Sleeper? Uses and Classification […]

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