The Great Indian Peninsular Railway Company was incorporated in 1849. It is to be the great line which is to unite Bombay with Madras, and also with Calcutta. From Bombay to Callian may be considered the parent line, as it is at this point it becomes divided, one branch going south-east in the direction towards Madras, and the other north-east towards Calcutta. The south-eastern branch is carried over the Bhore Ghaut by an incline nearly sixteen miles long, with a total elevation of 1,381 feet. The foot of the mountain is 196 feet above high water mark at Bombay. Its average gradient is 1 in 48. The steepest gradients are 1 in 37 and 1 in 40, for a total length of 9 miles and 44 chains; 1 in 37 extends in one length for 1 mile 10 chains, and 1 in 40 for 5 miles 6 chains. Short lengths of level gradients and of 1 in 330 are introduced into this incline to facilitate the ascent of the engine. The radii of the curves upon it range from 15 chains to 80 chains; but as much as 12 miles 45 chains have a radius of more than 30 chains, and 5 miles 33 chains are straight. It comprises twenty-five tunnels of a total length of 3,585 yards. The longest is 437 yards; and the longest without a shaft, which is carried through a mountain of basalt, is 346 yards. There are eight viaducts of a total length of 987 yards. The two largest are 168 yards long, and respectively 163 and 160 feet above the foundations. The total quantity of cutting, chiefly rock, amounts to 1,263,102 cubic yards. The maximum depth of cutting is 70 feet, and the greatest contents 75,000 cubic yards of trap rock. The embankments amount to 1,849,934 cubic yards, the maximum height being 74 feet; and the greatest contents are 209,000 and 263,000 cubic yards. The slopes average about 1½ to 1. There are twenty-three bridges of various spans, from 7 feet to 30 feet, and sixty culverts from 2 feet to 6 feet wide. The rails weigh 85 lbs. per yard. The cost of the incline has been nearly £800,000; at one time there were no less than 42,000 men (natives of India) employed upon its construction.
At the eleventh mile the incline is divided into two banks by what is called a reversing station. This subdivision, however, was not adopted for the purpose of making two banks of the incline, but of increasing the length of the base, in order to flatten the gradient and to reach a higher level, where it encountered the great features of the Ghaut margin, near Khandalla. Without the necessary expedient of the reversing station, the practicability of changing the direction of the line would have been confined to making curves of small radius; but with the device of the reversing station the direction was altered at a very acute angle, by means of points and crossings. In consequence of its adoption, the length of the line has necessarily been considerably extended.