In these days when modernisation is the buzz word in the railways, a Mumbai local train is struck in a time warp. One of the oldest railway lines between Karjat and Khopoli runs on an ancient 19th century system - old token signalling system that involved carrying a physical steel ball token to continue its journey.
The 15-km section between Karjat and Khopoli, about 100 km from Mumbai, still uses the age-old system since there’s just a single track and single train at any given point in time. The Karjat Khopoli section is one of the country’s oldest railway sections opened in 1856 by the erstwhile Great Indian Peninsula Railway (GIPR), now called the Central Railway.
The system, called Neale’s Ball Token Instrument, was introduced during the British rule. Designed by an engineer with the GIP Railway named Neale, the signaling system involves an electro-mechanical instrument provided at each station on single line railway sections. It ensures safety in train operations by dispensing tokens, which are handed over to train drivers as authority to run the train and proceed ahead.
The tokens are spherical steel balls, which are issued in such a manner that only one token can be issued for one direction at a time after ensuring that previous train has already cleared the section and there is no other train between the stations. The steel balls are tied to a racquet-shaped cane ring and handled from the train driver to the station staff at Palasdhari and Khopoli, the two end stations on the line.
Each station has one such instrument for each direction, which are electrically connected to similar instruments provided at the adjoining stations on either side. This ensures that only one train can enter the block sections at a time.
“In the single line sections, it is one of the most safe and foolproof methods of signaling even in today’s modern era. This method is called as absolute block signalling system as against the commonly used automatic signalling system in the more intensively used suburban sections,” a senior official said.