NTES is the salt of Railfanning. IRI is the sugar. - Kirti Solanki

Both mumbai and pune are big cities and railway line passes right through them.
Had this been on diesel you would have needed loco change at both ghat beginning and end almost compulsorily to prevent Alco belching fumes right inside people's houses, and this would have wasted almost one hour per train, thereby reducing sectional capacity unnecessarily.
There is reason this line has been electrified since pre-indepednce times (also has to do with TE of steam locos and its ability to negotiate steep grades, but that is another story)..

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