With the construction of a shorter railway line for a part of the route, the 403.8 kilometres (250.9 mi) stretch was assigned a separate identity.

[1][2] The Loop from Khana Junction to Kiul via Jamalpur, including the Monghyr branch, was ready in February 1862.

The work included EIR's first tunnel at Jamalpur and first major bridge across the Son River at Arrah.

After approx 150 years of operation, Sahibganj loop is converted in double line on 14-05-2019 except Ratanpur–Jamalpur section as construction of tunnel near Jamalpur is in progress.

In the Rail Budget 2008, Bhagalpur was announced to be converted to as Railway Division but decision withdrawn by ER in 2009.

[5] Work on the new 130-kilometre (81 mi) long Rampurhat–Dumka–Mander Hill broad-gauge line completed and Kavi Guru Express BhagalpurJn to Howrah is running on this route.

It was felt that communities of gunsmiths and other craftsmen in the area handling mechanical engineering jobs could pick up the skills required in a railway workshop.

The electrification of Bonidanga Link Cabin–Barharwa–Sahibganj–Kiul section including the Tinpahar – Rajmahal section (Announced by Prime Minister Package in Bihar) has been started from September 2017 and was expected to be completed by the end of March 2020 but got delayed due to COVID-19 pandemic and was completed on 30 June 2020.

After approximately 150 years of operation of Kiul–Bhagalpur section of Sahibganj loop, Vikramshila Express became the first train to be hauled by an electric locomotive on 2 June 2019.

The next day it departed and ran with the same electric loco from Bhagalpur Junction till Anand Vihar Terminal.

The electrification of the further loop line between Bhagalpur to Bonidanga Link Cabin was delayed due to doubling work between Sahibganj–Bhagalpur section which was completed in the month of April 2019.

With the completion of electrification of Sahibganj loop from (Bonidanga Link Cabin to Kiul) distance of total 247 rkm, it became a history by becoming 100% fully electrified.

The Howrah–New Delhi oldest rail route was constructed in the late 1880s by the British Government (East India Company) and thus, it ended the longest running era of diesel locomotives.

According to the NFR zone, the national transporter will save an amount of around Rs 20.4 crore per annum in its fuel cost, for running this train on electric traction between Pandit Deen Dayal Upadhyaya Jn (formerly Mughalsarai Junction) and New Jalpaiguri Jn railway stations.

Finally, the whole Sahibganj loop route has been electrified and the last CRS inspection was done on 30 June 2020 between Bhagalpur and Shivnarayanpur.