A Historic Day Today:
It's due to the decision of the Bombay High Court in 1919 making it mandatory for GIPR and BBCIR to electrify their suburban lines from BBVT to Kalyan and from Colaba to Virar. Accordingly various surveys were undertaken by GIPR and it was finalised by GIPR to electrify the Harbour Branch first till Kurla, the sole reason being the gradients encountered in between Masjid and Kurla Stations were inefficiently handled by steam locomotives hauling suburban trains. Thus a clean era also referred to as the "Push Button Traction" was formally inaugurated on 03-02-1925 at BBVT platform number 2 in morning hours at 10am when a four coach EMU zoomed out and commenced it's 16 kilometre run and...
more... terminating at Kurla.
"Push Button Traction" completes 92 glorious years on entire IR today.
The Extract Summary from M/s. Merz & McClellan Report concerning the Railway Electrification of the Suburban Lines of Bombay (October 1913) states that there was a detailed comparative analysis of 1500V DC Traction, 3000V DC Traction and 15000V AC fed at (50/3 Hertz i.e. 16.667 Hertz) Traction for Bombay's suburban railways. With various traction system proposals along with their merits and demerits concerning the financial and technical aspects of each.
Due to the outbreak of World War 1 in the year 1914, all the proposals were dropped temporarily and entire railway organisations in British India started catering to England's war needs.
When peace returned in the year 1918, GIPR again asked M/s. Merz & McClellan to reconsider and recommend proposals for Bombay's suburban railway. This time in their report they proposed to GIPR 1500V DC Overhead Traction for their Suburban Networks (BBVT-VDLR-CLA/BA and BBVT-KYN) and 3000V DC Overhead Traction for the lines beyond KYN till IGP on NE line and till PUNE on SE line.
After due considerations of all the proposals by the railway consultant, GIPR decided to adopt 1500V DC Overhead Traction for electric railways that shall be operating in and around Bombay and on the lines traversing the heavily graded Sahyadri hill ranges