Calcutta Chord link line

The Howrah-Bardhaman Chord, a shorter link to Bardhaman from Howrah than the Howrah-Bardhaman Main Line, was constructed in 1917. In 1932, the Calcutta Chord Link Line was built over the Willingdon Bridge (now known as Vivekananda Setu) joining Dum Dum with Dankuni and opened for freight traffic, thus forming a direct link from Calcutta (now known as Sealdah railway station) to Dankuni on the Howrah-Bardhaman Chord, thus earning the line it's name.[4][5]

By 1950-51, Santragachi was heavily congested causing delays in arrival for trains bound to Howrah.[6] Two major reasons identified for the congestion were it's railway yard outstripping it's capacity and passing of freight trains of the South Eastern Railway from Kharagpur towards Chitpur and Kolkata docks taking the circuitous route via Tikiapara, Liluah, Belanagar and then finally taking the Calcutta Chord link line to Calcutta.[6]

To resolve the congestion problem, Indian Railways sanctioned the remodelling of the Santragachi railway yard in November 1962 and sanctioned the building of a direct link from Andul on the Howrah-Kharagpur line to the Calcutta Chord link line in the railway budget of 1959-60. This was to reduce the distance between Andul and Calcutta Chord from 27.5 km (17.1 mi) to 13 km (8.1 mi).[6]

The work of building the line however progressed slowly due to land acquisition problems and was finally completed on December 1968.[6] The electrification of the line was started subsequently and was completed by 1971-72.[7][8]

The ACCL line was primarily used by freight trains to bypass the congested sections near Howrah and directly connected the Eastern railway and South Eastern railway zones. However with increasing public demand, some long distance passenger trains were started in this section directly via Sealdah like the Sealdah–Puri Duronto Express in 2012.[9]

The Dum Dum-Dankuni section was electrified in 1964-65. The Andul-Dankuni section was electrified in 1971-72.[8]

The doubling of the Dankuni-Bhattanagar section of the ACCL line was sanctioned on 2013.[10] The track doubling of the Andul-Baltikuri section was completed & commissioned on 25 January 2020.[11] With the completion of the track doubling of Baltikuri-Bhattanagar section on October 2021, the entire ACCL line was doubled. This removed a critical bottleneck affecting interchange of trains between Eastern Railway and South Eastern Railway.[12]