Indian Railways/Rolling Stock

Zonal Railways Railway Infrastructure Introduction Indian Railways has a rolling stock. Rolling stock is the general name for the railway vehicles that move on railway tracks. It includes vehicles that carry their own source of power and vehicles that must be hauled by another vehicle. In Indian Railways, rolling stock includes locomotives, coaches, wagons, electric multiple units, diesel multiple units, mainline electric multiple units, trainsets, tower cars, power cars, inspection vehicles, shunting vehicles, track inspection vehicles, and other special-purpose vehicles. Indian Railways uses rolling stock for two main purposes. Passenger rolling stock transports people and their luggage, while freight rolling stock transports goods such as coal, iron ore, cement, food grains, petroleum products, containers, automobiles, and other materials. Locomotives and self-propelled train units provide the power needed to move these vehicles. The Indian Railway Rolling Stock Code defines rolling stock broadly to include coaches, wagons, locomotives, electric multiple units, diesel multiple units, trainsets, mainline electric multiple units, tower cars, power cars, special-purpose coaches and wagons, and other railway vehicles. Rolling stock is designed according to its purpose. A high-speed passenger coach requires different construction, suspension, braking, and interior arrangements from a coal wagon. A shunting locomotive needs good low-speed pulling power, while a passenger locomotive may need high speed and rapid acceleration. See also: Indian railway coaching stock Types of Rolling Stocks Self-Propelled and Non-Self-Propelled Stocks thumb|268x268px|Credit: Smeet Chowdhury. This is an EMU (Electric multiple unit) which is a self-propelled vehicle for intercity routes. (Train No. 38436) Rolling stock can be divided into self-propelled and non-self-propelled vehicles. A self-propelled vehicle has its own equipment for producing or receiving motive power. Examples include locomotives, electric multiple units, diesel multiple units, railcars, battery vehicles, and some maintenance vehicles. A non-self-propelled vehicle cannot normally move independently over the railway. It must be hauled or pushed by a locomotive or another powered unit. Passenger coaches, freight wagons, parcel vans, brake vans, and many inspection vehicles belong to this group. The word “stock” refers to a vehicle or group of vehicles available for railway service (here). A passenger train may contain a locomotive, several coaches, a pantry car, luggage or brake vans, and sometimes a power car. A freight train may contain a locomotive or multiple locomotives and a large group of wagons. Locomotives, Coaches and Special Stocks thumb|335x335px|Credit: ActStuffOGWiki. This is an EF12K. It is a locomotive which is just two older WAG-9 locomotives combined. The principal groups of Indian railway rolling stock are locomotives, coaching stock, freight stock, multiple-unit stock, maintenance vehicles, and emergency or special-purpose vehicles. Locomotives provide the main hauling power for conventional trains. They may use diesel engines, electric traction equipment, batteries, or, in heritage service, steam engines. Coaching stock is used mainly for passengers. It includes sleeping coaches, sitting coaches, air-conditioned coaches, general coaches, chair cars, first-class coaches, pantry cars, luggage vans, brake vans, generator cars, parcel vans, postal vans, and special coaches. Freight stock consists mainly of wagons. Different wagons are designed for bulk goods, liquids, containers, automobiles, livestock, military equipment, cement, coal, grain, steel, and other commodities. Multiple-unit stock consists of vehicles in which traction equipment is distributed among one or more coaches. Electric multiple units, mainline electric multiple units, diesel multiple units, and modern trainsets can operate without a separate locomotive in the usual way. Maintenance and special-purpose stock supports the railway itself. This group includes track machines, overhead-equipment inspection cars, tower cars, breakdown cranes, accident-relief vehicles, medical vans, inspection carriages, engineering vehicles, and departmental wagons. Locomotives A locomotive is a powered railway vehicle designed mainly to haul or move other railway vehicles. It normally does not carry passengers, although some locomotives may contain limited crew accommodation. Locomotives are attached to coaches or wagons using couplers. A locomotive may pull a train, push it, or move vehicles inside a yard. A locomotive used for moving vehicles short distances in a station or yard is called a shunter or switching locomotive. A locomotive used on the main line is designed for longer distances and higher speeds. Locomotives are classified according to their power source, gauge, intended duty, transmission system, axle arrangement, and power rating. Indian locomotive codes traditionally provide information about several of these features. The first letter generally identifies the gauge, the second identifies the motive power, and the third identifies the service or traffic role. Steam Locomotives thumb|302x302px|Credit: Nigel Tout. This is a YP (Y for narrow gauge, P for passenger traffic) steam locomotive from 1993 at its retirement. Steam locomotives use a boiler to produce steam. The steam drives pistons or turbines, which turn the driving wheels. Coal, oil, or another fuel is burned to heat water inside the boiler. They were historically important in India. They hauled passenger and freight trains for many decades before diesel and electric traction became dominant. Steam locomotives required regular attention to their boilers, water supply, fuel, lubrication, and mechanical parts. Steam locomotives are no longer the normal source of power for Indian Railways. A small number are preserved for heritage operation, special excursions, museums, or ceremonial use. They are valuable because they demonstrate an earlier stage of railway technology. The main advantages of steam locomotives were their ability to operate without external electrical infrastructure and their relatively simple fuel supply arrangements in the early railway era. Their disadvantages included heavy maintenance, low thermal efficiency, smoke, the need for frequent water and fuel stops, and the labor required to operate them. Diesel Locomotives Diesel locomotives use a diesel engine as their prime mover. In most large Indian diesel locomotives, the diesel engine drives an electric generator or alternator. The electricity then powers traction motors mounted on the locomotive’s axles. This arrangement is known as diesel-electric transmission. thumb|266x266px|Credit: Kishlay RF. This is a WDP-4D (W for broad gauge, D for diesel power and P for passenger traffic) locomotive in Kochi. A diesel-electric locomotive is not usually driven mechanically like a road vehicle. The diesel engine produces electrical power, while traction motors provide the turning force at the wheels. This allows the locomotive to produce high tractive effort and to control wheel rotation effectively. Diesel locomotives were introduced widely because they required less routine servicing than steam locomotives and could operate on routes without electric overhead equipment. They were especially useful during the transition from steam to electric traction. Diesel locomotives have been progressively replaced on many main lines by electric locomotives. They remain useful on non-electrified routes, in yards, for shunting, during maintenance work, and in situations where independent power is required. Indian diesel locomotive families have included passenger, freight, mixed-traffic, shunting, and dual-mode types. Examples of familiar Indian classifications include WDM locomotives for broad-gauge diesel mixed traffic, WDP locomotives for passenger service, WDG locomotives for freight service, and WDS locomotives for shunting. Electric Locomotives Electric locomotives receive electrical energy from an external supply system. On most electrified broad-gauge routes in India, electricity is supplied through overhead equipment. A pantograph on the locomotive touches the overhead wire and transfers electricity to the locomotive’s traction system. thumb|292x292px|Credit: Indian Railways. This is a very popular image of a WAP-4 (W for broad gauge, A for AC current and P for passenger traffic) locomotive with ICF Blue. The locomotive converts the incoming electrical energy into mechanical power through traction motors. Modern electric locomotives use power electronics, transformers, converters, control systems, and regenerative or dynamic braking equipment. Electric locomotives have several important advantages. They can provide high power, strong acceleration, and high tractive effort. They do not carry fuel tanks or large diesel engines, and they produce no exhaust emissions at the point of use. Electric traction is particularly suitable for heavily used routes and long freight trains. Electric traction also requires substantial fixed infrastructure. The railway must provide overhead equipment, substations, switching systems, protection systems, maintenance facilities, and reliable electricity. Electric locomotives cannot normally operate independently on a route without compatible electrical equipment. Indian electric locomotives include passenger, freight, mixed-traffic, and shunting types. Common classifications include WAP for broad-gauge electric passenger locomotives, WAG for broad-gauge electric goods locomotives, and WAM for electric mixed-traffic locomotives. Alternative-Powered Locomotives Battery-powered railway vehicles store electrical energy in onboard batteries. They may be used for inspection, shunting, maintenance, station service, or other limited duties. Their use depends on battery capacity, charging facilities, vehicle weight, operating range, and local requirements. thumb|267x267px|Credit: Suvadeep Saha56. This is a WDAP-5 locomotive (W for broad gauge, D for diesel locomotive, A for AC Current and P for passenger traffic). It is the only dual-mode locomotive in India. Hybrid and dual-mode vehicles can use more than one source of power. A dual-mode locomotive may use electric power under overhead wires and diesel power where electrification is unavailable. Such vehicles can reduce the need to change locomotives at the boundary between electrified and non-electrified routes. Alternative-power railway technology may also include fuel-cell, hydrogen, or other low-emission systems in experimental or limited applications. The suitability of each technology depends on energy supply, infrastructure, cost, maintenance, and safety. Passenger Coaches A passenger coach is a railway vehicle designed to carry people. It may provide seats, sleeping berths, toilets, luggage space, heating, cooling, lighting, electrical outlets, food-service facilities, or accessibility features. Passenger coaches are built in different forms. Some are intended for short suburban journeys, while others are designed for overnight travel. Some provide air-conditioned accommodation, while others have open windows and simpler interiors. A coach may be self-generating or end-on-generating. In a self-generating coach, an alternator and axle-driven equipment produce electrical power as the coach moves. In an end-on-generation system, one or more power cars supply electricity to the entire rake through an electrical train line. Passenger coaches may be connected by vestibules. A vestibule is an enclosed passage between coaches that allows passengers and staff to move safely from one coach to another while the train is in motion. ICF Coaches ICF coaches were developed around the integral-coach design associated with the Integral Coach Factory. They became one of the most widely used passenger-coach designs in India. An ICF coach generally has a conventional body and bogie arrangement. It may use coil springs, air brakes, and other systems depending on its construction and later modifications. thumb|310x310px|Credit: ActStuffOGWiki. These are ICF Uthkrisht coaches powered by a WDP-4 locomotive. ICF coaches have been produced in many forms, including general coaches, sleeper coaches, air-conditioned coaches, chair cars, pantry cars, luggage vans, generator cars, and special-purpose vehicles. The ICF design served Indian Railways for a long period because it could be manufactured and maintained in large numbers. Many coaches received upgrades during their service lives, including improved braking, suspension, lighting, toilets, electrical systems, and interiors. LHB Coaches LHB means Linke Hofmann Busch, the name associated with the coach design developed in Germany and later produced for Indian Railways. LHB coaches use a different design from older ICF coaches. LHB coaches generally have stainless-steel bodies, FIAT-type bogies, disc brakes, improved suspension, and centre-buffer couplers. Their design provides improved crashworthiness and ride characteristics compared with older coach designs. thumb|253x253px|Credit: Ravi Dwivedi. LHB coaches of Sangam Express at some railway station. LHB coaches are available in several passenger configurations. These include air-conditioned first class, air-conditioned two-tier sleeper, air-conditioned three-tier sleeper, air-conditioned chair car, executive chair car, non-air-conditioned chair car, sleeper, general seating, pantry, power, luggage, and brake-van variants. The exact capacity of a coach depends on its layout, seat or berth design, toilet arrangement, accessibility provisions, and production version. For example, commonly cited LHB configurations include approximately 52 berths for some air-conditioned two-tier coaches, 72 berths for some air-conditioned three-tier coaches, 78 seats for some chair cars, and 56 seats for some executive chair cars. These figures can vary by design and refurbishment. LHB coaches are often associated with higher-speed passenger services, but the actual permitted speed of a train depends on the coach type, locomotive, track, signalling, route conditions, maintenance status, and operating rules. Freight Wagons A freight wagon is a railway vehicle used to carry goods. Wagons are designed according to the physical properties, weight, volume, loading method, unloading method, and safety requirements of their cargo. A wagon must support its load, withstand pulling and braking forces, remain stable on curves, and operate safely at the permitted speed. It must also be compatible with loading terminals and unloading equipment. Freight wagons may be open, covered, tank-type, flat, hopper-type, container-carrying, automobile-carrying, or specially designed for a particular commodity. Indian Railways uses many wagon types because the country transports a wide range of bulk and manufactured goods. The wagon fleet has changed over time as freight patterns, axle loads, loading technology, and logistics systems have developed. Open and Covered Wagons See also: Open wagon Open wagons have no permanent roof. They are suitable for goods that are not easily damaged by weather or can be protected by tarpaulins. thumb|Credit: Adityamadhav83. Two open wagon goods trains (both coal trains) and one is pulled by a WAG-7. They are widely used for bulk materials such as coal, minerals, stone, scrap, and other commodities. Some open wagons have doors, bottom discharge equipment, or special side arrangements. Open wagons can be loaded by conveyor, shovel, loader, hopper, or other mechanical systems. Their unloading method depends on the design and the receiving facility. Open wagons are also one of the most common freight wagons used in Indian Railways. They are mostly coal trains but other freight trains such as wood, paper, scrap and metal trains. Covered wagons have a roof and enclosed sides. They protect goods from rain, dust, sunlight, and some forms of contamination. They are suitable for food grains, bagged cement, fertilizers, manufactured goods, paper, packaged products, and other materials requiring protection. Covered wagons may have sliding doors, roller doors, end doors, or special loading openings. Their internal fittings may be adapted to prevent movement or damage to the cargo. Covered wagons are also one of the most common types of freight wagons found in India along with open wagons. Hopper and Tank Wagons Hopper wagons have sloping internal surfaces and discharge openings. They are designed to release bulk materials through gravity. Coal, ballast, ore, grain, and other materials can be handled efficiently using hopper wagons. Discharge may occur through bottom doors, side doors, or controlled outlet systems. The receiving terminal must have suitable tracks, pits, conveyors, hoppers, or unloading equipment. Hopper wagon design and terminal design therefore work together. Tank wagons carry liquids, gases, powders, or other materials in a tank mounted on a railway underframe. Different tank wagons are designed for petroleum products, chemicals, water, liquefied gases, edible oils, and other substances. The tank material, pressure rating, valves, insulation, safety fittings, and labelling depend on the cargo. Tank wagon operations require strict attention to loading limits, pressure, leakage prevention, earthing, fire protection, brake equipment, and emergency procedures. Tank wagons are the third most common freight wagons in Indian Railways as they can carry milk, oil and water. Multiple Unit Trains A multiple-unit train is formed from several connected vehicles that operate together. Traction equipment is placed in one or more vehicles, and the train is controlled from a driving cab. Multiple-unit operation allows the driver to control all powered vehicles from one cab. This is useful for frequent-stop services because the train can accelerate quickly and does not need a separate locomotive at each end. Indian Railways operates electric multiple units, mainline electric multiple units, diesel multiple units, and trainsets. Their designs differ in power source, interior arrangement, speed, range, and operating environment. Electric Multiple Units (EMU) and Mainline Electric Multiple Units (MEMU) An electric multiple unit receives power from an external electrical system and distributes traction equipment among several cars. EMU trains are widely used in suburban and regional services. They typically have many doors, high standing capacity, rapid boarding and alighting, and strong acceleration. An EMU formation may contain motor coaches, trailer coaches, driving coaches, or combinations of these. The exact formation depends on the electrical system and train design. EMU braking may combine air brakes with electrical braking. Regenerative braking can return energy to the electrical system when conditions permit. thumb|267x267px|Credit: WillaMissionary. To the left, (the green and yellow one), we have a MEMU from Delhi's suburban rail. To the right, (the red, blue and yellow one), we have an intercity EMU from Delhi. A mainline electric multiple units is designed for longer-distance regional or intercity operation than a conventional suburban EMU. It may provide more seating, fewer doors, greater luggage capacity, toilets, air conditioning, or improved ride quality. Some mainline units are built as self-propelled passenger trains with driving cabs at both ends. The term MEMU is commonly used for mainline electric multiple units. MEMU services are useful on electrified routes where passengers require frequent regional connections without a locomotive-hauled formation. Many people however cannot differentiate between a MEMU (Mainline Electric Multiple Unit) and an EMU (Electric Multiple Unit). One difference is that EMUs are used in the rest of the world too, while MEMUs are an Indian Railways exclusive. Diesel Multiple Units (DMU) and Diesel Electric Multiple Units (DEMU) A diesel multiple unit uses diesel engines distributed among one or more coaches. It does not require overhead electrical equipment. DMUs are suitable for non-electrified routes and regional passenger services. thumb|267x267px|Credit: Belur Ashok. A 9-year-old DEMU (Diesel Electric Multiple Unit) from Secunderabad to Manoharabad. Diesel Multiple Units may have driving cabs, passenger coaches, power cars, and trailer cars in different combinations. DMUs can provide rapid acceleration and efficient service on lightly or moderately used routes. Their disadvantages include fuel consumption, exhaust emissions, engine noise, and the need for diesel maintenance facilities. A diesel electric multiple unit is a type of diesel multiple-unit train in which diesel engines generate electricity, and electric traction motors use that electricity to turn the wheels. It is therefore a specific type of DMU, not a completely separate category. Indian Railways describes DEMUs as self-propelled formations containing driving power cars and trailer cars. The diesel engine in a DEMU does not usually drive the wheels directly like DMUs. Instead, it drives an alternator or generator. The generator produces electrical energy, which passes through control equipment and traction converters to electric motors connected to the wheelsets. Future The future of Indian railway rolling stock is likely to involve greater electrification, more trainsets, improved passenger information systems, more energy-efficient equipment, better accessibility, stronger crashworthiness, and increased use of digital diagnostics. Freight wagons may become more specialised and may support higher axle loads, faster freight services, containerisation, automobile transport, and automated handling systems. Locomotives may receive improved traction converters, regenerative braking, remote diagnostics, energy monitoring. Maybe hybrid or dual-mode locomotives will become more popular. Maintenance is also becoming more data driven. Sensors and software can identify wheel defects, bearing temperature, vibration, brake conditions, electrical faults, and other problems before they lead to service failures.