This Tablet Token Block instrument was manufactured by Westinghouse Brake & Signal Co. Designed by Neale, an engineer with the then Great Indian Pennisular Railway, it is 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 enter a block section. Tokens 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. 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.