Tunnel across the Rajmahal range was made between 1860-1861 and was the
bottleneck in the faster proliferation of the East India Railway
network, which started off from Howrah to Raneegunje(Raniganj,
collieries near Asansol)[121 miles, 1855], reached Jamalpur (1862),
reached Prayag 1862) and Delhi (1866) and finally Lahore (1866).