What happens when the chain is pulled in a typical Indian passenger train?

It may be a fun for many,but it increases the work of already overburdened railway running staff and also waste the precious time and delay the train.

The alarm chains are connected to the main brake pipe of a train. This brake pipe maintains a constant air pressure, helping the train move smoothly. When the emergency chain is pulled, the air stored in the brake pipe escapes, through a small vent. The drop in air pressure leads to the slowing down of the train. The loco pilot quickly notices this drop in the air pressure and starts maneuvering the train. As the train runs on narrow rails, so it cannot be brought to a sudden standstill, as that could lead to imbalance causing derailment.

the loco pilot can override the emergency brake only in certain situations. There is a bit of history involved behind the overriding logic. In the olden days, when dacoits were a big threat, loco pilots were given clear instructions to override emergency brakes when passing through crime prone areas. But the rules have been changed somewhat today. If a present day loco pilot overrides the emergency braking system in train, then the person is answerable to the higher authorities for such an action.

As soon as the alarm chain is pulled, the RPF personnel reach the coach within no time at all. This makes many wonder – how? Well, the train coaches are fitted with emergency flashers, situated on the side walls of the coaches. The flashers from the coach (in which the chain was pulled) are activated as soon as the emergency chain is pulled. A light also starts blinking and buzzing within the locomotive pilot’s controls until the Guard, Assistant Driver and RPF personnel reach the location of the chain pulling and are able to manually reset the chain. Once the chain is reset, the air pressure gradually comes back to normal and the train is ready to depart.

As per the Indian Railways Act , pulling the emergency chain without a valid reason is an offence and attracts a jail term of three years, or a fine up to Rs 1,000.