[1] It is linked to the Sealdah Main and North section via the Kankurgachi Chord line at Park Circus and via the Kolkata Circular Railway at Majerhat Junction.

[6][7] The Gangasagar mela, which attracts thousands of pilgrims during Makar Sankranti in mid-January, and is held in Sagar Island is approached through the Namkhana branch line of this section.

[19][20] In 1868, CSER having suffered extensive losses due to floods and other problems, sold the line to the Indian government (management then being leased to the Eastern Bengal Railway (reporting mark :EBR)) and the company was dissolved in March 1870.

[1] While multiple feasibility reports and proposals, beginning from 1839, were made for the construction of a railway line between Calcutta and Diamond Harbour, no action were taken on these.

[17][18][19][20] A small 0.81 km (0.50 mi) branch line was constructed in 1883, from Diamond Harbour to Hara Fort near the Hooghly River to transport goods and military supplies as well.

[17][18][27] The Calcutta Port Commissioners' Railway (reporting mark :CPCR) built a branch line from Kidderpore Docks to Majerhat on 1893.

The tracks were dismantled and the land was reclaimed to build a road, now called James Long Sarani, in Behala.

[19][20] The Sealdah South section lines are fully electrified with 25 kV AC overhead system.

[5] As of November 2021, the Sonarpur Carshed had 32 12 Coach EMU rakes which exclusively served the Sealdah South section.

[5] Multiple new lines and extensions on this section have been planned by the Eastern Railway; however, most remain blocked due to land issues.

[36] Planned branches to Raidighi and Durgapur The 20 km (12 mi) long Jaynagar Majilpur–Raidighi line via Krishnachandrapur was sanctioned in 2009-10.

In 2017, a preliminary survey for a 138 km (86 mi) long line was sanctioned by the Indian Railways in order to boost connectivity between Dankuni and the proposed deep sea port at Sagar Island.