How are tracks joined? What is a fishplate? How does TPWS work? How are ballasts stored beside the tracks?

The rails for the train tracks are manufactured in small pieces around 20 meters each that make up the rail network of 67,956 kilometers in India. They need to be joined. So they are joined with one another with the help of thermal welding that helps in smooth operation. 

To prevent the tracks from getting dislocated due to thermal expansion (the expansion that occurs in a straight line is called linear expansion) in direct sunlight under heavy pressure when the train moves, at some points they are joined leaving a thin gap between them using a fishplate.

TPWS stands for Train Protection Warning System. This is an emergency speed sensor that prevents the train from an accident or decreases the degree of the accident. They are fitted in between the track 50 to 450 meters of an upcoming signal. TPWS uses three main components:

• Over Speed Sensor abbreviated as OSS tracks the speed of the train from where it is placed in the track of an upcoming signal.
• Train Stop System abbreviated as TSS receives the signal from the ground device and intimate the same to the AWS.
• Automatic Warning System abbreviated as AWS receives the signal from the TSS and intimate the same to the loco pilot through audio and visual message. If the loco pilot doesn't respond to it, it will apply the emergency breaks of the train.

Ballasts are stored by the railway authority in the form of a trapezium. This helps them in many ways.

It becomes easy to find how much ballast is stored by calculating the volume of the trapezium.

To prevent it from getting stolen they are marked with white lines of lime dust.

The perfect shape also provides great stability to the ballast stored.