ROLLING STOCK

What Is Rolling Stock?

• The term Rolling Stock in rail Transport industry refers to any vehicle that move on a railway.
• It usually includes both powered and unpowered vehicles, for example:

1. Locomotives
2. Railroad Cars
3. Coaches
4. Wagons

Rail Transport

• Rail Transport is a means of transferring of passengers and goods on wheeled vehicles, running on rails, also known as Tracks. It is also commonly referred to as train Transport.

How Different is Rail transport from Road transport?

• In contrast to Road transport, where vehicles run on a prepared flat surface, rail vehicles(Rolling Stock) are directionally guided by the tracks on which they run. 
• Tracks usually consist of Steel Rails, installed on Ties(sleepers) and ballast, on which the Rolling Stock, usually fitted with metal wheel, moves.
• Rolling Stock in a Rail Transport system generally encounters lower frictional resistance than Road vehicles, so passengers and freight cars(carriages and wagons) can be coupled into longer trains.

Source of power

• Power is provided by locomotives which either draw electric power from a railway electrification system or produce their own power, usually by diesel engines.

History of Rail Transport

• Rail Transport commenced in the mid 16th century in Germany in the form of Horse-powered funiculars and Wagon ways.

Modern Rail Transport

• Modern Rail Transport commenced with the British development of the steam locomotives in the early 19th century.

Rails/Tracks

• The introduction of Bessemer process, enabling Steel to be made inexpensively, led to the era of great expansion of Railways that began in the late 1860s.
• Steel rails lasted several times longer than Iron.
• Steel rails made heavier locomotives possible, allowing for longer trains and improving the productivity of railroads.
• The Bessemer process introduced Nitrogen into the Steel which caused the Steel to become brittle with age.
• The open hearth furnace began to replace the Bessemer process near the end of the 19th century, improving the quality of Steel and further reducing costs.
• Thus Steel completely replaced the use of Iron in Rails, becoming standard for all Railways.

Rolling Stock Wheels

Gauge

Types of Gauge

• Broad Gauge(1676mm)
• Standard Gauge(1435mm)
• Meter Gauge(1000mm)

Locomotive

• A Locomotive or engine is a Rail Transport vehicle that provides motive power to a train.Types of Locomotives:

• Passenger Locomotives
• Freight Locomotives(wagons and carriages)

Difference between Passenger Locomotive and Freight Locomotive

• Passenger Locomotives develop less starting Tractive effort but are able to operate at high speeds.
• Freight Locomotives are normally designed to deliver high power, at the sacrifice of maximum speed.

Electric Locomotive

• An Electric Locomotive is a Locomotive powered only by Electricity

How is Electricity  supplied to moving Trains?

• Electricity is supplied to moving trains with a(nearly) continuous conductor running along the track that  usually takes one of the three forms: an Overhead line, a Third Rail mounted at track level, or an onboard battery.
• Both Overhead wire and third-rail system usually use the running rail as the return conductor but  some systems use a separate fourth rail for this purpose.
• The type of Electrical power used is either Direct Current(DC) or Alternating Current(AC).

The Earlier and Modern System at a Glance

• Earliest systems were DC systems.
• In 1891, Charles Brown(Germany) demonstrated the first practical AC Electric Locomotive.

Motive Force

• In Thermodynamics, Motive Force is a natural agent, such as water or steam, wind or electricity, used to impart motion to machinery such as engine.

Traction Motor

• A Traction Motor is an Electric Motor used for propulsion of a vehicle, such as an Electric Locomotive.
• Traction Motors are used in Electrically Powered Rail vehicles.
• DC Motors with series field winding are the oldest type of Traction Motors.
• Nowadays, AC Induction Motors and Synchronous Motors, being simple and require low maintenance, are commonly used.

Multiple Unit(MU)

• A Multiple Unit is a self propelled train composed of one or more carriages joined together, which when coupled to another Multiple Unit can be controlled by a single driver.
• MUs are classified on the basis of their power source and are of two main types:

1. EMUs(Electric Multiple Units)
2. DMUs(Diesel Multiple Units)

• A MU has the same power and traction components as a locomotive, but instead of components being concentrated in one car, they are spread throughout the cars that make up the unit.
• The INDIAN RAILWAY uses DMUs & EMUs on its National Network. All Suburban and Rapid Transit lines are served by EMUs.

Rapid Transit

• Rapid Transit is a passenger railway in an Urban area with high capacity and high frequency.
• Rapid Transit is also referred to as Mass Rapid Transit(MRT), Metro or Heavy Rail.

More About Rapid Transit System

• Rapid Transit systems are Electric railways that operate on an exclusive right-of-way, which can not be accessed by pedestrain or other vehicles of any sort and which is often grade separated in tunnels(underground) or an elevated railways(overhead).
• Modern services on rapid Transit systems are typically provided using Electric Multiple Units(EMUs) on rail tracks.
• The Stations typically have high platforms, without steps inside the trains, requiring custom made trains in order to minimize the gaps between train and platform.

Then What Is A METRO?

• Metro is the most common term for underground Rapid Transit Systems used by Non-Native English Speakers.

History of Rapid transit System

• The Worlds first Rapid transit system was the partially underground Metropolitan Railway which opened as a conventional railway in 1863.

Did you Know?

• China has the Largest number of Rapid transit systems in the world.
• Shanghai Metro is the worlds largest single operator of Rapid Transit system by Route length.

Area of Application of Rapid Transit

• Rapid Transit is used in cities and Metropolitan areas to transport large number of people often over short distances at high frequency.

Transit Map

• A Transit Map is a Schematic diagram used to show the routes and stations. The main components are color-coded lines to indicate each line or service.

Risk and Security measures associated with Rapid Transit

• Compared to other modes of transport, Rapid Transit has a good safety record.
• Head-on collisions are rare due to use of double track, and low operating speeds reduce the occurance and severity of rear-end collisions and derailment.
• The risk of people falling onto the tracks of high platform(over 1m/3ft.) can be eliminated by the use of platform screen doors.

Advantages of Rapid Transit

• Rapid Transit is seen as an alternative to an extensive road transport system with many motorways. 
• The Rapid Transit system allows higher capacity with less land use, less environmental impact.