Construction materials

civil techniques

Metal Sleepers

abbu riyaz 1 May, 2023

Metal sleepers use widely in the modern construction of railway tracks. The Metal sleepers are of cast iron and steel. In these various types of Metal sleepers, the sleeper which is economic uses in the construction of railway tracks.

Cast iron is widely engaging than steel because of its less tendency to corrosion. Metal sleepers use widely because of the shortage of wooden sleepers and its long life properties.

Types of Metal Sleepers

There are many Types of Metal Sleepers using in the construction of railway rail tracks. The following types are as follows,

Cast iron Sleepers and

Steel Sleepers

Cast iron Sleepers

The Cast iron sleepers are using widely in the construction of railway rail tracks. Cast iron are of many types as follows,

Bowl or Pot sleepers
Plate sleepers
Box sleepers
C.S.T-9 sleepers
Rail Free Duplex sleepers.

The main reason to use metal sleepers replacing wooden sleepers are because of growing scarcity of wooden sleepers.

Steel Sleepers

The following types of Steel Sleepers are as follows,

Key Type
Clip-Bolt Type
Spring Type

Requirements of Metal sleepers

Metal Sleeper should bears the compression and tensile stress acting on it.
It should be of low manufacturing cost and low maintenance.
It should provide proper grip on the rail track
And provide ballast to prevent dislocation of track due to vibrations and shocks cause by heavy loads.
Sleepers must be economical.
t should be easier to handle during the maintenance operations like lifting, packing, removal, and replacement.
The weight of sleepers should not be too heavy or too light.
It should have a moderate weight for ease of access.
And capable to resist shocks of rails because of a fast-moving load with vibration.
It should have a proper spacing between two sleepers for ease of maintenance for removal and replacement.
Sleeper to design in a way that they should not push out easily due to moving loads.
A sleeper to provide with anti-theft qualities.

Construction materials

Types of wooden Sleepers

abbu riyaz 1 May, 2023

There are many Types of wooden Sleepers using in the construction of railway rail tracks. As it satisfies all the needs of a sleeper it is using mostly in the construction of railway rail tracks.

Types of wooden Sleepers

There are many Types of wooden Sleepers using in the construction of railway rail tracks. The following types of wooden Sleepers are as follows,

Hardwood and

Softwood

EKKA, SAL, TEAK are some of the most using types of sleepers in the construction of railway rail tracks. These wooden sleepers are hard than any other wooden sleepers. It is heaver too.

Treatment of wooden Sleepers

The lifetime of wooden Sleepers increases 30% – 50% by treatment. There are so many chemical treatments involves in the treatment of wooden Sleepers. There are three main methods for treating timber sleepers

Full cell process
Empty cell process
Haskenizings process

Timber has millions of minute cells. These cells have many ingredients in it. The removal and refilling of ingredients are the treatment of timber sleeper.

Methods of Construction wooden Sleepers

There are many important methods of construction of wooden Sleepers.

The good looking fair wooden Sleepers to use on each side of rail joints.

The sleepers to lay centrally along tracks.

Place good side of sleepers downwards and poor side upside.

The sleepers to place at exactly 90 degrees.

The correct size of drills to make in sleepers for fixing.

A proper and correct spacing to maintain in the laying of track.

Enough air and ventilation to provide at stacking of wooden sleepers.

Extra and spare holes to pack with a wooden plug to avoid entry of water inside the track.

civil techniques

Wooden sleepers in Railway Tracks

abbu riyaz 1 May, 2023

Wooden sleepers in Railway Tracks plays a major role. It is the best. And it satisfies all the needs of a sleeper. In the Railway bridges, the railway rail tracks are of timber sleepers. It is because of its less weight, high load carrying capacity and its ability to absorb shocks and vibrations. The lifetime of wooden sleepers depends upon the ability to resist all chemical, physical and mechanical deformations.

The chemical deformations are damages because of the chemical attacks in woods, like efflorescences.

The physical deformations are because of the insect attacks like termites, white ants, decay, etc.

The mechanical deformations are the damages by the abrasions and wear & tear because of heavy moving loads in high-speed tracks.

1. Specifications of the wooden sleepers

It should be free from cracks, and other defects.

It should sound through.

And should be straight without curves.

It should saw parallel on the top and bottom faces.

Edges are of a square shape.

2. Advantages of the Timber sleepers

Timber sleepers are easily available.

It is easy to lay and construct a railway rail track.

Lightweight material.

Having a high load carrying capacity.

High tendency to absorb shocks and vibrations.

Having simple and easy fittings.

Easy to maintain and repair tracks.

Low maintenance cost.

Highly economic.

Gives less noisy track.

Require fewer fittings and simple design.

Withstands wear and tear due to heavy moving loads.

3. Disadvantages of the Timber sleepers

Gets easily attack by termites, white ants, insects.

Difficult to maintain the gauge of rails.

Difficult to maintain track alignment.

Less lifetime compares to other sleepers types.

wooden Sleepers are the old traditional material used in the construction of railway track sleepers. It satisfies all needs of a good sleeper. The life of wooden sleepers depends on many facts like wear and tear, decay, and attack by termites, etc. And because of a high scarcity of wooden sleepers, it is replacing with the metal and concrete sleepers.

civil techniques

Classification of Sleepers

abbu riyaz 1 May, 2023

There are many Classification of Sleepers. Sleepers classify according to the materials uses in the construction of railway rail tracks. The sleepers are of concrete, timbers, steel, cast iron, RCC, and the Prestress concrete. In these various types of sleepers, the sleeper which is economic uses in the construction of railway tracks.

And the climatic and geological considerations considers in making a decision of using the type of sleeper according to needs. The classifications of sleepers are as follows,

Classification of Sleepers

There are Many types of sleepers makes in the construction of the railway tracks.

Wooden Sleepers
Metal Sleepers
Concrete Sleepers

1. wooden Sleepers

wooden Sleepers are the old traditional material used in the construction of railway track sleepers. It Satisfies all requirements of a good sleeper. It absorbs shocks and vibration due to heavy moving loads. The life of wooden sleepers depends on many facts like wear and tear, decay, and attack by termites, etc.

In the Railway bridges, the railway rail tracks are of wooden sleepers. It is because of its less weight, high load carrying capacity and its tendency to absorb shocks and vibrations.

2. Metal Sleepers

The Metal sleepers are of cast iron and steel. Metal sleepers use widely in the modern construction of railway tracks. Cast iron is widely engaging than steel because of its less tendency to corrosion. Metal sleepers use widely because of the shortage of wooden sleepers and its long life properties.

3. Concrete Sleepers

The Concrete sleepers are using more than any other sleepers because of its unique properties. They are more resistant to wear and tear. It withstands blows and vibrations cause due to heavy moving loads. And it is fewer subjects to chemical attacks, termite attacks, and more corrosion resistance.

There are two types of sleepers they are,

Reinforced Concrete sleepers
Pre-stressed Concrete sleepers

civil techniques

Railway Track Sleepers

abbu riyaz 1 May, 2023

Railway Track Sleepers are members which lay transverse to the rails on which the rail supports and fixes. Sleepers are concrete beds in the railway tracks. The sleepers are of concrete, timbers, steel, cast iron, RCC, and the Prestress concrete. The main role of sleepers is to transfer load from rails to the ballast. And the sub-grade below. It as a transverse member throughout the permanent way.

These sleepers fix vertical to each other. It fixes throughout the track. The main work of sleepers is to hold rails in a strong position. It receives the loads from rails and spread to ballast and sub-grades.

Functions of Railway Track Sleepers

Sleepers perform the following functions

It holds the rails at the proper gauge and at the proper level, flat curves, turnouts, and in diamond crossings.

Transfers load evenly from rails to ballasts to absorb vibrations of moving loads.
Provides a good stability of track.
The track circuiting is making easy with it.
Supports the rail tracks at proper super-elevation.
It acts as an elastic medium in between the ballast and the rails to absorb blows.
It maintains the horizontal and vertical alignments throughout the entire track for a long lifetime.
They provide a way to rectify track geometry during its use.

Requirements of Railway Track sleepers

For a long time period and for a good performance the sleepers need to some important requirements.

Sleepers must be economical.
Should have a low maintenance cost.
It should be easier to handle during the maintenance operations like lifting, packing, removal, and replacement.
The weight of sleepers should not be too heavy or too light. It should have a moderate weight for ease of access.
And capable to resist shocks of rails because of a fast-moving load with vibration.
It should have a proper spacing between two sleepers for ease of maintenance for removal and replacement.
Sleeper to design in a way that they should not push out easily due to moving loads.
A sleeper to provide with anti-theft qualities.

civil techniques

Railway Rail Tracks

abbu riyaz 1 May, 2023

Railway Rail Tracks are the main important components in tracks. Rails are unsymmetrical I-sections. It composes of steel. Rails lay parallelly over sleepers. Railway Rail Track lies parallel to the entire track. Rails carry the wheel load of trains providing them a smooth way. And transfer the load safely to sleepers.

These rails are of high carbon steel to resist and withstand wear and tear. Rails joints together longitudinally with welding and with fishplates.

Functions of Railway Rail Tracks

Rails in the Railway Track serves the following purposes:

Rails transfer loads from wheels safely to sleepers and ballasts.
Provides a smooth level surface for movement of trains.
Provides an unchanging surface for passage of heavy moving loads with minimum friction between steel rail and wheels.

It guides the wheel of trains throughout the trackway.
High carbon steel has high strength, stiffness, and durability.
The web of rail is strong enough and support head of rails.
Rails acts as girders and bear stress develop by heavy vertical/lateral loads, breaking force and thermal stress.

Length of Railway Rail Tracks

Longer rails are highly economic. And it gives a high strength. Joints are weak points in Railway Rail Tracks. So long rails consider mainly than short rails. Short rails consume more rail joints. This decrease the efficiency of rails. These rails joints with welding and by fish plates.

In the modern railways with the technological advancement, keeping gaps between rails avoids. The welding of rails introduces. These rails welds into three rails, five rails and ten rails. Welding of jointing rails is by melting them together. These welding rails has many advantages. It is economical, low maintenance, increase stability, reduce creeps. Creeps are longitudinal movement of rail tracks. It is common to all railway rail tracks. It measures regularly in rail tracks. A creep of up to 150 mm permits in rail tracks.