Pradeep Pattanayak

Most of us have train journey experience. During the journey, we come across several letters, numbers, signs and signals written on trains as well as put up on platforms. You must have noticed WAG, WAP, WDM, WAM etc on locomotives or train engines of Indian Railways. Have you ever thought what they mean? 

Let’s understand this. 

The first letter of these codes, ‘W’ implies the gauge of the railway tracks, which is five feet. The engine’s power can be understood from the second letter ‘A’ and ‘D’. While ‘A’ signifies the source of the power is electricity, ‘D’ means the train runs on diesel. 

Similarly, from the third letters ‘P’, ‘G’, ‘M’ and ‘S’, the purpose of the engines is understood. ‘P’ means it is a passenger train, ‘G’ means, it is a goods train, ‘M’ means, it is used for mixed purposes and ‘S’ stands for ‘shunting’.  
Now let’s try to decode these codes.

If you noticed ‘WAG’ written on a train engine, you have to understand it that it runs on wide gauge tracks and is an AC motive power engine, used for pulling goods train. Similarly, if you come across ‘WAP’ written on an engine, you shouldn’t take time to understand that it runs on wide gauge tracks and runs on AC motive power and pulls a passenger train.

If it is written ‘WAM’ on any engine, its meaning is simple. While it runs on wide-gauge tracks, it is an AC motive power engine used for pulling both passenger and goods train. 

Sometimes you may find ‘WAS’ written on engines. It means they are AC motive power engines and run on wide gauge tracks. Their use is for shunting purposes.