1. Railway Overhead Fitting
Introduction
Railways are the cheapest mode of transport for traveling from one
state to another. They are highly serviceable for both the passengers as
well as for carrying goods. With such a major contribution of railways
to the Indian economy, all the components and fittings required for the
construction of the complete body, have their own significance. Many
a manufacturing units of these components and fittings are
continuously engaged in coming up with innovative products as per
latest technology. One of the most important parts of a train is the overhead fittings which
constitute the most important aspect of railways.
What is an Overhead Fitting?
Overhead Fittings are also known as overhead lines or overhead wires.
Before going into further details, it is important to know what is an
overhead fitting or an overhead line. According to Wikipedia, Overhead
lines are wires used to transmit electrical energy to trolley buses, trains
and trams at a distance from the energy supply point. Overhead lines are
used on the basis of one or two overhead wires situated above the
railway tracks and raised to a high electrical potential by connection to feeder stations at
regular intervals. These feeder stations derive electricity from high-voltage electrical grid.
Electric trains receive electric current from overhead line system using several specialized
devices such as Pantograph, Bow Collector or a Trolley Pole. These current collection devices
are pressed against the underside of the lowest wire of an overhead line system known as
acontact wire. The current collectors are electrically conductive, and allow current to flow
through to the transformer of the train or tram, and back to the feeder station via the steel
wheels and one or both running rails of the track.
Usage of Railway Overhead Fittings
There are mainly three kinds of trains which avail the use of railway overhead fittings. Various
kinds of overhead equipments are used depending upon the size of the rail. These different
types of rails where these overhead fittings are absorbed are the following:
Light rail
Heavy rail
Trolley bus.
What is Light Rail?
It is a form of train that uses electric rail cars sometimes used in streets.
The term Light Rail was coined in 1972 by the U.S. Urban Mass
Transit Association (UMTA) to welcome the appearance of new
streetcar transformations which were taking place in Europe and the
United States. The history of light rail can be delineated from the horse
drawn street railways or a horse car which was drawn using animals
like horse. Here the term 'light' is used to describe the light load and
fast movement rather than its physical weight. The American Public Authority defines light

2. rail as: "An electric railway with a 'light volume' traffic capacity compared to heavy rail". Also
light rails are much more affordable than heavy rails.
Overhead Line Equipment for Light Rail
Various kinds of overhead line equipments are available which are used
specifically in light rails. These equipments make use of smaller and light
weight components that contribute in reducing the overall visual impact of the
system. The various kinds of equipments used in light rails are:
Catenary equipment
Single wire
Trolley wire
Hybrid.
Definition of Heavy Rail
Heavy rail is entirely different from light rail and is used for regular
railways. Heavy trains are those, the services of which we commonly use
for the purpose of traveling from one state to another i.e. a normal
passenger train. It is also used for loading and unloading goods. Since
these trains are used for carrying passengers as well as freight, the curves
and slopes are gentle. In countries like U.S., the term light rail is used to
describe the metro systems but is different from commuter rail and inter city rail services.
Before the 2nd World War, heavy rails existed in Boston, Philadelphia and Chicago. With the
advent of the war, new systems were opened in other states of U.S such as Cleveland,
Baltimore, Washington, the San Francisco-Oakland region, Los Angeles, Atlanta, and Miami.
Today heavy rails is used in almost all the countries of the world including India.
Overhead Line Electrification for Heavy Rail
Heavy Rails use electrification systems i.e they use electricity to propel
their engines to enable them to move ahead. There are many advantages
associated with it like faster acceleration, less noise and lesser air
pollution. However the biggest disadvantage is the cost involved in
installing the electrification equipments. Different specialized
components are used for for overhead line electrification systems. A partial list of these
products under the category of Main-line and Sidings includes:
Poles/Masts
Droppers
Clamps
Insulators
Steady Arms
Terminations
Knuckles
Spring Droppers
Cantilevers
Brackets
Section Insulators.

3. The above products are also used as overhead line equipments for Trolley Buses.
Trolley Buses
Trolley Buses are simply electric buses which are run with the help of
overhead wires from which it draws electricity with the help of two
trolley poles. Trolley Buses use rubber ties instead of steel wheels on
rails. These buses are easy to run on hilly areas as electric power is
much more effective here than diesel power. Also they are very much
environment friendly than other trains and do not make much of
unnecessary noise. One of the disadvantages of a trolley bus is that if it is dewired, it is left
stranded for hours without any power supply. Less number of power lines are also responsible
for trolley buses not being used frequently.
Overhead Line Equipment for Trolley Bus Systems
Equipments used in Trolley Buses are the same as those used in
Heavy Rails but mainly cover Straight lines and curves and crossings
and switches .
Products Related to Railway Overhead Fittings
Different products related to Railway Overhead Fittings are Railway Track Components like
Fish Plates
Glued Joints
Rail Clips
Screw Spikes
Track Spikes
Grooved Rubber Sole Plates
Side Bearer Pads
Insulators
Dowels
Inserts
Industrial Fasteners
Railway Tracks
Signal Wagons
Fittings
Forging components.