The Mumbai–Chennai line is a railway line connecting Chennai and Mumbai cutting across southern part of the Deccan Plateau. It covers a distance of across Maharashtra, Karnataka, Telangana, Andhra Pradesh and Tamil Nadu. The Mumbai–Chennai line is a part of Diamond Quadrilateral. Sections The -long trunk line, amongst the long and busy trunk lines connecting the metros, has been treated in more detail in smaller sections: Central line (Mumbai Suburban Railway) Mumbai Dadar–Solapur section Solapur–Guntakal section Guntakal–Renigunta section Renigunta–Chennai section History The first passenger train in India from Chhatrapati Shivaji Maharaj Terminus in Mumbai to Thane ran on 16 April 1853 on the track laid by the Great Indian Peninsula Railway. The GIPR line was extended to Kalyan in 1854 and then on the south-east side to Khopoli via Palasdari railway station at the foot of the Western Ghats in 1856. While construction work was in progress across the Bhor Ghat, GIPR opened to public the Khandala–Pune track in 1858. The Bhor Ghat incline connecting Palasdari to Khandala was completed in 1862, thereby connecting Mumbai and Pune. The Western Ghats presented a big obstacle to the railway engineers in the 1860s. The summit of the Bhor Ghat (earlier spelt as Bhore Ghat) incline being 2,027 feet. The maximum gradient was: 1 in 37 with extreme curvature. "The works on the Bhore ghat comprised 25 tunnels of a total length of nearly 4,000 yards, two of the longest being 435 yards and 341 yards respectively. The Bhore ghat have eight lofty viaducts having a total length of 2,961 feet. Two of the largest are more than 500 feet long with a maximum height of 1160 and 163 feet. There are 22 bridges of spans from 7 to 30 feet and 81 culverts of various sizes." The construction of the Bhor Ghat incline came at a high price: an estimated 24,000 builders died during the eight years of construction. The Pune–Raichur sector of the Mumbai–Chennai line was opened in stages: the portion from Pune to Barshi Road was opened in 1859, from Barshi Road to Mohol in 1860 and from Mohol to Solapur also in 1860. Work on the line from Solapur southwards was begun in 1865 and the line was extended to Raichur in 1871. Thus the line met the line of Madras Railway thereby establishing direct Mumbai–Chennai link. The first passenger train in southern India and the third in India