British-era split of the Bengal Nagpur Railway (1955)
Indian Railways' first zonal reorganisation in 1951–1955 merged 42 princely and company-era rail systems into six zones. The 1955 carve-out created South Eastern Railway from parts of the former Bengal Nagpur Railway, anchored on Calcutta and the eastern mineral belt.
The new structure gave Indian Railways a manageable span of control after independence and standardised operations across the network.
It established that mineral-rich freight corridors warrant their own zone, a logic that has driven every subsequent split, including the coastal-port economy that justifies SCoR.
SCoR follows the same mineral-and-port logic: the Vizag steel-coal-bauxite corridor and Krishnapatnam Port concentrate enough freight to justify a standalone zone.
