is a series of mountain slopes in the Western Ghats traversed by this line. From Kalyan to Kasara, the line covers a length of and rises to an altitude of above sea level at Kasara. The next section from Kasara to Igatpuri is across Thul Ghat and within that distance the line rises from to the gradient in the section being 1:37. The line negotiates this steep incline with the help of curves. The Ehegaon viaduct along this line is long and high. According to IRFCA, "The viaduct is situated in a steep valley nestling in the midst of hills that skirt around it in the tunnels and then is carried across the yawning chasm on a tall imposing structure… Some of the viaducts and tunnels on this line are considered outstanding achievements in Civil Engineering and are among the finest works in the world."
The first train in India traveled from Chhatrapati Shivaji Terminus railway station in Mumbai, then known as Boribunder, to Thane on 16 April 1853. Within about a year Great Indian Peninsula Railway connected the Mumbai-Thane line to Kalyan. Service up to Igatpuri was started in 1865. Before that, Bhusawal station was set up in 1860 and most of the line between Bhusawal and Igatpuri was laid in 1861-62 but the line was activated in mid-1860s, after completion of the line across Thul Ghat.
Branch lines
The Tapti Valley Railway linked Surat, on the Bombay, Baroda and Central India Railway, to the Great Indian Peninsula system at Amalner in the Khandesh region, in 1900. It was one of the railways set up by Killick Nixon Limited. The Manmad-Daund line was opened in 1878 and connects the two main sections of GIPR. The line is being doubled. The Hyderabad-Godavari Valley Railways opened the Manmad-Secunderabad line in 1900. The Chalisgaon-Dhule line was opened in 1900. The Pachora-Jamner narrow gauge line was opened by Central Province Railway in 1919.
The long wide broad gauge Puntamba-Shirdi link, connecting Shirdi to the Manmad-Daund branch line was completed in 2009. The Manmad-Puntamba-Sainagar Shirdi line was electrified in 2011-12.
New lines
have cleared the construction of Manmad-Indore and Nashik-Pune new lines after sixteen years of active lobbying.
The Kalyan-Igatpuri section was electrified with 1.5 kV DC overhead system in 1929. Subsequent electrification with 25 kV AC overhead system in the Igatpuri-Manmad sector, with AC/DC change over at Igatpuri, was carried out in 1967–69. The Manmad-Bhusawal sector was electrified in 1968–69. The change over of mainlines in the Mumbai area from DC to AC traction was completed in June 2015. There are large loco sheds at Bhusawal and Kalyan, and the smaller trip sheds at Manmad and Igatpuri. The loco shed at Bhusawal was established by the Great Indian Peninsula Railway in 1919. At that time it was the largest in Asia and third largest in the world. WAM-4, WAP- 4, WAG-5, WAG-7, WCM-6, WCG-2, WCAM-3 and WCAG-1 electric locomotives find a place in these sheds. Kalyan also houses some diesel locomotives.
Speed limits
The entire Howrah-Nagpur-Mumbai line is classified as a "Group A" line which can take speeds up to 160 km/h. The branch lines have speed limits within 100 km/h.
