How Locomotives are classified by Indian Railways

Locomotives can run under their own power or can run drawing power from elsewhere, converting fuel into pure kinetic energy that you can feel just by looking at it. And these are just two types of locomotives. There are many more types and identifying these locomotives is even a major sport across the World. In India, it is possible to know everything about a locomotive just by looking at it or by looking at a notation and it is no rocket science.

Classification of Locomotives in India by Type

Locomotives can be broadly classified into what fuel they use. But they can also be classified according to the gauge they run on. Then again, they can still be classified according to what work they are used for and according to their power. So which parameter do we use to classify locomotive types? Easy. We use all of them! To avoid confusion and to uniquely identify locomotives according to what they do and how they work, Indian Railways have developed a stunningly simple system which classifies locomotives into different classes taking into account all their parameters like Gauge, Traction, Usage, Version, Power etc. Locomotives are divided into the broadest classes at first and then sub-classified into narrower parameters and are given a notation or name which is basically a string of alphabets and numbers, which each letter or number representing a unique parameter of the loco or engine. These derived classes are called “Class Names” or “Class Types”. There may by hundreds or thousands of units of one class type or there might be none or below 10 units of another type.

Each locomotive Class Name will consist of three or four alphabets followed by a number and then an optional alphabet or two. Each of these letters can be said to be a “slot”, which can be filled by a predefined set of alphabets or numbers to denote some characteristic of the loco such as the gauge on which it runs, the traction it uses, the work it is supposed to do, the power rating/model/variant of the locomotive etc. The Class Name can be found painted on the front, back and sides of the loco. The most common classes of locomotives in India are the YDM4, WDM2, WDM3A, WDG3A, WDS4B WDP4, WDG4, WAM4, WAG5, WCAM2, WAP1, WAP4, WAP5, WAP7, WAG9 etc. It is important to note that the class name is assigned by the Railways for ease of classification and NOT by the manufacturer.

To illustrate what these strings of letters and numbers mean, here is an example: WDM3A:

 

The First Letter – The Gauge it Runs on.

The first letter in all Class Names stands for what track gauge the locomotive will run on, officially called “Gauge“. The letters that will appear in this slot are W, Y, Z and N, each representing a particular type of gauge. If a W appears in the beginning of the class name, it will denote a locomotive running on Broad Gauge track (1676 mm). If it is a Y it tells us that the loco will run only on Meter Gauge, Z is 2’6″ Narrow Gauge and N is 2′ Narrow Gauge. Now that all lines in India are being converted to Broad Gauge, non-W locos are becoming increasingly rare. Why W, Y and Z instead of, say, B, M and N? During British times, the three gauges for some reason were arbitrarily named X, Y and Z. After independence, X was changed to W, meaning “Wide” for the “Wide” Broad Gauge. The remaining two were left as they were. So, WDM3A is a Broad Gauge Locomotive.

The Second Letter – What Fuel it Uses.

The second letter in the class name notation stands for the type of traction used by the locomotive, or the power it runs on. Officially, “Power“. The letters that will appear here are D, A, C, CA and B. D denotes a Diesel Locomotive, an A denotes an AC loco running on 25 kV 50 Hz Alternating Current (AC) power, C denotes a loco running on 1500V Direct Current (DC) power, CA denotes a locomotive that can run on both AC and DC power and B denotes a loco running on battery power. C and CA type locomotives are found only in the Mumbai area as all of the remaining part of the country uses 25 kV AC power. And again, as all DC in the country is being converted to AC, we will not see more of C and CA locos. (Note, CA is considered a single letter). Now we know that WDM3A is a Broad Gauge Diesel Locomotive.

The Third Letter – What it Hauls.

The third letter in the class name notation specifies what type of work the locomotive is best suited for, called “Load“. The load can be denoted by P, G, M, S, U, R which shows what type of work the loco is best suited to do. If the third letter in the class name of a locomotive is a P, it will mean it is specifically meant for hauling trains running passenger services (expresses, mails, local, passenger, anything), a G will denote a locomotive best suited for Goods (Freight) trains and if it is M, it says that the loco can be used for any service, Passenger or Goods (Mixed). An S denotes a low powered shunting locomotive, a U designates EMU rakes (local train rakes) which have motors housed in the rake itself and don’t have separate locomotives. There is another one R which denotes a Railcar. So far, the WDM3A is a Broad Gauge Diesel Locomotive for Passenger and Goods Services.

Note: The first three alphabets of the class name are together called a “Sequence” denoting the basic classification or the locomotive model type. The remaining letters just denote variants just like the version numbers for software releases.

The Fourth Number – Power/Version.

The fourth slot in the class name will always be occupied by a number. This number is called “Series” denotes different things for Diesels and Electrics. For all WDM3X, WDGx and WDPx series Diesels other than WDP1, this number denotes the Horsepower rating of the engine as multiples of 1000 hp. So a 2 will denote a locomotive with an engine with more than 2000 – 3000 hp power rating. For all non-WDM3X series Diesels, all Electrics and all non-BG locomotives, the Series notation just denotes the chronological version/model of the locomotive. The First AC powered loco was a WAM1 and then came WAM2, WAM3 etc. A new version number can mean a new model altogether (WAM3 to WAM4) or a major upgrade of an existing model (WAP1 to WAP4). New version numbers can be also given even to new prototype testing locos which have only small numbers built like the WCM6 (only two in existence), WAM3 (only 10 produced) or  WDP3 (Only Prototypes). This is why there are over 50 classes of locomotives in India but only around 15 are widely produced and in service. Our WDM3A now is a Broad Gauge Diesel Locomotive for Passenger and Goods Services which has 3000 hp+ pulling power.

The Fifth Letter – The Subtype

The fifth and in most cases the last letter is called a “Subtype” and is the most confusing of all. It can be a letter or a number and may arbitrarily denote anything from power rating to unique factors of the loco. For all WDM/G/P3Xdiesels only, the subclass annotation will be letters denoting incremental hp power in multiples of 100. “A” denotes 100 hp added to the 3000 hp, “B” denotes 200 hp, “C” is 300 hp, “F” denotes 600 hp and so on. So a WDM3Fwill have an engine with 3600 hp power. For all other locomotives, diesel or electric, the Subtype annotation can mean anything, including major or minor modifications to original loco types, addition of components, rebuilds or any other unique identification factors. Some locomotives have even a sixth or more alphabets/numbers called a “suffix”. For Example, WDM2A – WDM2 with Airbrakes, WDP4D – WDP4B with Dual Cabs, WAG5HB – WAG5 with Hitachi traction motors built by BHEL, WAG9H – a Heavier WAG9 with better Tractive Effort, WAM4PD – A WAM4 assigned specifically for Passenger duties which has Dual Brakes etc.

Add ’em Up and you Have your Loco Class!

So a WDM3A is a Broad Gauge Diesel locomotive good to haul both Passenger and Freight trains, with a power rating of 3100 hp. In the same way by mixing matching all these letters we can get all class names of any locomotive types. YDG1 means a first version Meter Gauge Diesel locomotive for Goods trains. WDM2 is a 2000+ hp powered Broad Gauge Diesel locomotives for all services while a WDG4 is a 4000 hp Broad Gauge Diesel locomotive for hauling goods trains. YAM4 denotes a 4th version AC electric traction Meter Gauge loco for all services, a WAP4 is a 4th version AC electric Broad Gauge loco specifically for passenger services while a WAG7is a 7th version Broad Gauge AC electric Goods locomotive. WCAM3 is a 3rd version Broad Gauge locomotive which can run on both AC and DC current and can be used for both Passenger and Goods services. WDS6 is a 6th version Broad Gauge Diesel Shunting locomotive, ZDM1 is a Diesel Narrow Gauge all-purpose loco and so on.

Ideally, all these alphabets can be mixed and matched to cover all locomotives on IR, and even some imaginary ones can be created, like YCG (Meter Gauge DC Electric Freight loco), WCAP (Broad Gauge AC/DC Electric Passenger loco) etc, which do not exist but are perfectly feasible.

The Road Number

In addition to the Class name, every locomotive is assigned a unique 5-digit number called a Road Number. This is a serial number given to the loco by the Railways taken from a pool or range of numbers arbitrarily reserved for each loco class. Just by looking at the Road Number, a trained person can identify what class it belongs to. For example, Road Numbers for the WDP4 class run from 20000 till 20103, which will make loco #20076 a WDP4. The Road Number is displayed predominantly on the sides of the loco and on both ends. Some road numbers have a “R” affixed at their end, which indicates a loco rebuilt to that class from some other class. Many WDM3As are rebuilt WDM2s.

Locomotive Shed and Livery

Though locomotives run across the nation, they are “owned” by a particular depot or “loco shed” they are assigned to. Loco sheds maintain, repair and service locomotives and locos are known after their home sheds. All sheds have their own liveries or paint schemes called the “home colors” for all diesel and older class electric locomotives. The Ernakulum Diesel shed of Southern Railway for example, will have its locomotives painted broad Orange/Cream/Orange with an orange stripe on the Cream. The Ratlam shed locos will have Red on top and Black on bottom, separated by a narrow white band and so on. Newer Electric locomotives have a uniform color scheme across the country no matter which shed they belong to. So all WAP4s will be brick-red colored with an off-yellow band running around the bottom and all WAG9s will be green (except one, the #31086 Dr.Silver which is Red) with a yellow band around the bottom.

Locomotive Spotting (Loco spotting)

Railfanning is one of the most popular hobbies in the World, followed by people who are enthusiastic about everything trains and Railways and who follow this hobby are called Railfans, and locospotting is a popular railfanning activity. Locomotive Spotting is identifying a locomotive (alone or as part of a train) when one sees it and recognizing details about it: what type it is, what traction it uses, what class it belongs to, when/who built it, what it is hauling, who owns it, where it is going to/coming from and so on. Some people are very serious about this, and have databases about locomotives of their own. Many people have “favorite” locos, and keep track of their movements comparing notes with fellow Railfans who may spot them.

How to Spot Locomotives

Most locomotives of a type look the same. It would be difficult for an untrained eye to identify a loco when they see them, especially Diesels since all WDMs look almost the same with only size and details being differentiating factors. Electric locomotives also might seem to look the same but they are quite different and are easily distinguishable by color. The best way to identify locomotives is to look at four things that are painted on it. One: the Class Name, Two: The Road Number, Three: The home shed name (and color) and Four: The Division it belongs to. These four identifiers together make up the full name of the locomotive. So if someone says SWR KJM WDM3A #14012, it can be understood that the loco in question is a WDM3A class locomotive with Road Number 14012 belonging to the Krishnarajapuram (KJM) shed of South Western Railways (SWR). It will be blue/green/blue in color.

The most widely recognized locomotive in India of course still remains the WDM2. All WDM series (ALCO) loco designs are based on the iconic WDM2 (All locos shown above). WDP4s and WDG4s are easily recognizable thanks to their mighty looks and the weird shaped LHF end. All electric locos will always have forward cabs looking outwards at either end. All WAM locos look like boxes while all WAP and WDP sequence locos have tapering, aerodynamic ends. Among electric locos, the most widely seen ones are the WAM5 and theWAP4. (Note: They are pronounced as W-A-P or W-A-G and not “wap” or “wag”) Shunters on the other hand, are all smaller than the usual locos and are denoted by S.

The Locomotive World of the Railfan

There are of course, innumerable subtypes, rebuilds, rarities and subclasses for all the major locomotive types, a sighting of which can really make the day of a Railfan. Like the WDM2 “Jumbos” which have one of their ends rebuilt to include a makeshift forward-looking cab so that drivers did not have to lean out of the side window and had better visibility. Another (not officially recognized) subtype are “Baldie” WDM3As with a rounded on top short hood looking like a bald forehead. The WDM3A (#14012) shown above is a Baldie. Then there are named locomotives like the Baaz, Dr.Silver, Vallabh, Prayag, Panther, Samrat, Krisnaveni etc, and the occasional rarity of sighting of an odd livery (a WDM2 painted completely in Yellow), a rare locomotive (a WCM6 lying idle in the middle of nowhere), a dual-cab WDP4D, an imported locomotive like one of the old, original ALCOs or a GM EMD and so on. Our locos might not be as glamorous as their Western or Eastern counterparts, but the babies and beasts are still the best we have, they are the ones that move this country around!! Most people have theWAP7/WAG9 as their favorite locomotive, since it is the most modern and powerful we have. Then there are Diesel fanatics who swear by the ALCOs (WDM2) or WDP4s. For me, all are dear, though my favorite loco is theWAP4 #22522.

More about unique characteristics about individual locomotives in the next episode

The Darjeeling Himalayan Railway

 

 

The Darjeeling Himalayan Railway, opened in 1880, is an engineering feat. This little railway has a gauge of 2 ft. and a length of fifty-one miles, with steep gradients and amazing loops.

 Work on building the line began in May 1879, and in March, 1880, the Viceroy of India, Lord Lytton, had a journey on the train. In August 1880, the line was opened for passenger and goods traffic as far as Kurseong, 4,864 ft. above the sea and thirty-two miles from Siliguri. In July 1881, the line was opened throughout to Darjeeling station.

 On December 2, 1999, the Darjeeling Himalayan Railway became the second railway site in the world to be designated a World Heritage site. The railway has been added as a world heritage site with “outstanding universal value” by UNESCO’s World Heritage Committee.

The Gaikwad Baroda State Railway

 

In 1863, just ten years after the first train ran in India, the Gaikwad of Baroda state built a railway, which was of just two and a half feet gauge. Baroda was rich in cotton and following the American Civil war during1861-1865, the Gaikwad decided to grab the opportunity of exporting cotton from his state to the markets in England.

The maiden line of the Gaikwad Baroda State Railway (GSBR) was constructed quickly between Dhaboi and Miayagam. The Durbar of Baroda had financed the project. The Gaikwad was in such a hurry to commence the project to export cotton that he employed bullocks -- bullmotives -- as engines to run trains instead of waiting for the actual steam locomotives to arrive from England.

 In those days, it took days to transport goods from England to India as the only international mode of communication was ships, which followed the time-consuming sea route round the Cape of Good Hope. GSBR’s steam locomotives arrived in India only in 1873. This was the first narrow gauge railway in India

Later, during the rule of Maharaja Sayajirao Gaekwad III, the railway's network was further expanded. In 1873, the Dabhoi-Miyagam line (the first 2 ft 6 in (762 mm) line) was re-laid with stronger rails to allow locomotives to be used, rather than oxen. However, locomotives were not regularly used on the line until 1880. During the Maharaja's reign, a large narrow-gauge railway network was set, which extended to Becharaji and many other places in Baroda State, with Dabhoi as its focal point. The network is still the largest narrow-gauge railway network in the world.In 1949, the Gaikwad Baroda State Railway was merged with the Bombay, Baroda and Central India Railway.

 

 

Battle of Track gauges

 Lord Dalhousie, while formulating the railway policy for India, had suggested that a uniform gauge system should be adopted for the entire Indian Railway network. The gauge, the distance between the two inner faces of the rails of a railway track, selected for India was of 5 feet six inches.

 Lord Dalhousie had stated that an intermediate gauge between 4'-8 ½" and 7'-0" was the best gauge especially for India which would substantially command all the possible benefits of the latter." The Court of Directors accepted 5'-6" as the gauge for India and the Government of India further confirmed their decision in favor of 5'-6" and in 1851, it was accepted as the standard gauge for the railways in India.

 

An official change in gauge

 The uniformity of gauge was maintained till 1862. But Lord Mayo, the then viceroy of India, was a great enthusiast of the metric system. He encouraged the building of meter gauge lines in India during his tenure. It was seen as a compromise between proposals for narrow gauge for use in areas with limited traffic.

 It was decided that the subsidiary lines to the main railway system, on which large traffic was not expected, should be constructed on narrow gauge light system and subsequently connected to a broader gauge. Thus, the meter gauge came into existence.

 Such was the craze of Lord Mayo for metric systems that he even wanted to replace other existing systems in the country, but was prevented by doing so by strong British bureaucracy. In fact, it was his predecessor, Sir John Lawrence, who had initiated the process of laying the meter gauge lines in India, which Lord Mayo took up with such zeal.

 Now, each time a railway line was proposed in India, fresh controversy over the gauge to be adopted arose.

 By 1889, the mileage of different gauges was -- broad gauge (5 feet six inches) 8,000 miles, meter gauge (I meter) 5,000 miles and narrow gauge 250 miles.

 Today, India has four major gauges -- broad (five feet six inches), meter (three feet three inches), two feet six inches (narrow gauge) and two feet (narrow gauge).

 

Trains Running in India

 

The line in Bombay was ready by November 1852 and on November 18, 1852, a few engineers and directors of the GIP Company had a trial run between Bombay and Thane. However officially, the first train in India (and in Asia) was flagged off on April 16, 1853, a Saturday, at 3:35 pm between Boree Bunder (Mumbai) and Thane, a distance of 34 kms. The importance of the day can be gauged from the fact the Bombay government declared the day as a public holiday.

The train, hauled by three engines -- Sindh, Sahib and Sultan -- carried as many as 400 passengers in its 14 coaches on its debut run. The Great Indian Peninsula Railway had ordered a set of eight locomotives from Vulcan Foundry, England, for the purpose. A suit of Durbar Tents erected at Thane welcomed the first train and a cover for four hundred persons was built with tables laid with menu literally groaning under every delicacy of the season.

India had, however, spotted one of its earliest locomotives as early as December 22, 1851. The first steam engine, Thomason, hauled some wagons containing mud and earth during the construction of the Solani aqueduct near Roorkee. The second one, Lord Falkland, named after a Bombay governor, was seen a year later near Byculla, Bombay, doing shunting duties. The third one was used for the trial run of the passenger train in November 1852. And it was only after all this that the much-publicised “official” first train saw the light of the day on April 16, 1853. Wasn’t it a long, long journey before the “official” first train saw the light of day.

And since then there has been no looking back.

The north, south and the east

By late 1850, agreements had been signed to prepare trial lines to run inland in Bombay (The Great Indian Peninsula Railway), Calcutta (East Indian Railway) and Madras (Madras Railway).

Calcutta, the then capital of India, on the western coast of the sub-continent was also in the race to be first to introduce railway into India. The survey from Calcutta to Delhi for the East Indian Railway was carried out during 1945-46. But the construction of railway line from Howrah to Raniganj was sanctioned only after three years.

But fate denied Calcutta the privilege of being the first city to have a railway in India. Locomotive and carriages for Bombay and Howrah were dispatched from England almost at the same time. But the ship carrying the loco for East Indian Railway, HMS Goodwin, was misdirected to Australia. The other ship carrying carriages for Howrah sank at the Sandheads.

Yet another problem that besieged east India was the dispute over the French territory of Chandernagar (Chandannagar) through which the railway line was to be aligned. The settlement of this dispute with French rulers took considerable time and Bombay won over Calcutta in the railway race.

It was finally on August 15, 1854 that the first passenger train in the eastern section ran between Howrah to Hooghly (24 miles). The section is soon extended to Pundooah.
In the south, the Madras Railway Company was formed in London as early as July 8, 1845. The shareholders held a general body meeting in February 1846 to construct a railway line from Madras to Arcot , known as Wallajah Nagar.

But matters were delayed and the actual construction begun on June 9, 1853. The first train between Royapuram and Wallajah Nagar steamed out on June 26,1856. The Bangalore section was opened an August 1, 1864. Railway lines to Nagari, Raichur, Bellary were completed subsequently,

in the north, the first train ran between Allahabad and Kanpur, a distance of 180 km, on March 3, 1859, six years after the first train.

The railways then were built on a Guarantee System, which meant that the railway companies were guaranteed a certain rate of interest on its capital investment. The guarantee was to be honoured by the East India Company.

The first Indian Rail Company

The bill to incorporate India’s first railway company, the Great Indian Peninsular Railway Company [G.I.P.R] (later it was rechristened as Peninsula), came up before the British Parliament twice. First in March 1847 and later in 1849.

 

In March 1847, the East Indian Company, which then ruled India, opposed the bill on certain clauses forcing it to be withdrawn. Matters dragged on till 1849 when Lord Dalhousie, who had experience in railway matters in England, took over as the Governor-General of India. On August 1, 1849, the Act to incorporate the Great Indian Peninsula Railway came into being.

The original contract made on August 17, 1849, between the East India Company and the Great Indian Peninsula Railway stated that the capital of the GIP Company shall be 5 lakh pounds, but can be subsequently increased to one million pounds in case the railway line has to be extended beyond Callian (Kalyan) and across the Thull and Bhor Ghats. The railway line has been referred to as an “Experimental line of Railway” throughout the contract.

How it all Began - The Indian Railway

Indian Railways, which had a modest beginning in 1853, has since then been an integral part of the nation  a network that has held together a population of one billion. A self-propelled social welfare system that has become the lifeline of a nation, Indian Railways has woven a sub-continent together and brought to life the concept of a united India.

The railways in India are the largest rail web in Asia and the world’s second largest under one management. With a huge workforce of about 1.65 million, it runs some 11,000 trains every day, including 7,000 passenger trains. The tale of how railway communication gained foothold in India, where the locomotive was once considered as a “fire-spitting demon”, is indeed an interesting one.

 

In 1846, there was a major failure of cotton crop in America. Following this, textile merchants at Manchester and Glasgow in Great Britain had to seek alternative markets. It was then that traders in the UK turned their attention on the cotton crop in India, one of British colonies then, rich in cotton crop.

However, cotton was produced in various parts of the Indian sub-continent and it took days to bring it to the nearest port to transport it to England through ships, the only major means of international communication then. The British then had to build a link from the hinterland to India’s major ports for quicker transport of cotton and other goods as demand soared. This expedited matters for the British to introduce a railway in India.

The British also felt that organizing and dispersing the growing native population faster deployment of troops could be better handled by a railway.

As early as 1843, Lord Dalhousie had first conceived the possibility of opening up of India by means of railway communication. He had proposed to link the three ports of Bombay, Calcutta and Madras by a railway.

The same year he sent George T. Clarke, an engineer, to Bombay to assess the possibility. A few years later in 1845, a strong lobby in Bombay supporting railway communication formed a body called the Bombay Great Eastern Railway. As matters started to gain momentum, the Bombay Great Eastern Railway locally prepared plans for constructing a railway line from Bombay to the Deccan. But the British already had a concrete plan in their minds and soon things began to take shape.

The earliest proposal for laying railways in India was made some time around in the 1830s. Inspired by the railway mania in England, some eminent citizens in Madras had proposed the idea of a railway but plans remained on paper and the project did not see the light of the day then.

Conditions in India were quite different from those in Britain. Many British and Indians, who had a better understanding about India’s topography and geography, opposed the construction of railways as a "premature and expensive undertaking" and a "hazardous and "dangerous venture". Certain opponents doubted the feasibility of introduction of railways in India citing poverty, extreme climate with torrential rains, violent storms, high mountains, sandy deserts and dense forests.

But the process of building a railway network that would one day not only captivate the nation but the whole world had already begun.