In India we have largest network of railways. It is a cheapest mode for long distance travel. I think every one of us travel through train. Train covers larger distances in less time due to its higher average speed. Train journeys become sometimes boring due to its poor speed and too much stoppage. We have different class of train and each one has definite speed on its route. But due to signal and track conditions the train not able to follow its recommend speed. We sometime wonder what the speed of train in which we are travelling. To compare whether the speed of the train is less or more, you need to have some number. Recently started Gatiman Express running between Delhi and Agra claims to attains max speed of 160 km/hr.

I am describing the method to calculate the speed of train while sitting inside it. This is also a good pass time while travelling in train. We can calculate the speed of any train and compare the speed of Rajdhani trains with that of mail or express trains.

## What to do to find the speed of a running train.

First of all select any window seat and get seated there. Take out any stopwatch or use mobile inbuilt clock to use as stop watch.

When the train is running steadily i.e not accelerating, look for the milestone or mile posts outside the train window.

Milestones are built on the sideways of railway track to mark distance along the railways route. On some places you will not find the milestone due to less space or grasses or trees. Without milestone you will not be able to calculate speed of train. Therefore look for these milestones along the track.

If you are able to see milestone than just notice that it will appear every 1 km in the route.

The moment you see the milestone outside the window quickly start the time in your stopwatch or mobile.

Now let the 3-4 milestone passes the by your window. Stop the timing in watch just after you see the 5^{th} milestone. Note down the time period ‘t’.

Now Speed of train will be calculated using distance speed formula. Here how it is done.

## Formula to find the speed

Speed = Distance/time

Therefore Speed of train, km/hr.

*z- Number for milestone crossed during the noted time.*

*t- Time period measure in seconds.*

Suppose you observed 225 seconds for crossing 5 milestone then

*Speed = 5*3600/225 =80 km/hr*

Now Every time you do a train journey calculate the speed of train yourself and compare with the defined speed of these trains.

## Dos and Don’ts

Do not calculate speed of train while starting from a Station and during reaching a station. Because at that time the speed is not constant it is varying with time. It means the Train in accelerating or decelerating.

Look for more number of milestones to note the time period. This is required to calculate the average speed.

Dear Ramesh Kumar, your writeups on calculating the speed of a train and the SB interest are very useful. Even a layman can benefit from them. However, please make sure that there are no mistakes. E.g. in the example given above, you have written “Suppose you observed 225 section”. It should be 225 seconds.

Thanks for correcting. Appreciate your reading.