The railway line starts at Lo Wu or Lok Ma Chau, both of which are boundary crossing points into Shenzhen and joins in the north at Sheung Shui and ends at Admiralty station on Hong Kong Island.

The line connects the new towns of Fanling–Sheung Shui, Tai Po and Sha Tin in eastern New Territories with urban Kowloon and the central business district.

Today, a clock tower is the only structure left from the old terminus, and is a landmark near the Cultural Centre, Space Museum and the Star Ferry pier.

Six pillars dismantled from the original station building were relocated to the Urban Council Centenary Garden in Tsim Sha Tsui East.

The Kowloon-Canton Railway Corporation (KCRC) signed a contract with Anglo-French manufacturing giant GEC-Alsthom to refurbish the Metro-Cammell EMUs at the East Rail depot at Ho Tung Lau.

[17] Also as part of the ATP project, a two kilometre section of the tracks near the Pak Shek Kok reclamation, curving around the former coastline, was straightened out during the mid-1990s.

[18] A vestige of the former alignment, an old bridge beside Cheung Shue Tan village built between 1906 and 1909, was identified by the Antiquities and Monuments Office in 2008 as a historic asset.

At that time, the line terminated at East Tsim Sha Tsui in the south, and Lo Wu / Lok Ma Chau in the north.

[21] During the closure, Lo Wu station served only certified residents nearby, while passenger service at Lok Ma Chau was completely suspended.

Northbound trains terminated at Sheung Shui for three years, until Lok Ma Chau crossing was reopened on 8 January 2023 following the lifting of travel restrictions.

During the first two weeks after the extension's commissioning, the patronage of the line's critical link, that is the section from Tai Wai to Kowloon Tong, during the busiest hour in the morning peak recorded a 27% increase from 26,000 to 33,100 pphpd.

[31] As construction of the SCL project progressed, advance works for APGs installation including platform structure reinforcement was also carried out.

The line is currently served solely by nine-car R-Stock trains built by Hyundai Rotem, which entered service on 6 February 2021.

They fully replaced the older fleet in time for the opening of the Hung Hom to Admiralty section of the Sha Tin to Central Link on 15 May 2022.

Both Lo Wu and Lok Ma Chau stations are integrated with immigration control points between Hong Kong and Mainland China.

At 18:40, a Lo Wu-bound train carrying about 1,500 passengers reached the point where the double-tracked section of the railway ended ahead of the tunnel, near Yau Yat Chuen.

However, the accident caused train services to be suspended for the rest of the day and the incident spurred a series of public outcries concerning railway safety.

Coupled with a lorry accident in the Lion Rock Tunnel the same day, Kowloon and Sha Tin were thrown into "traffic chaos".

An independent investigation by the Electrical and Mechanical Services Department revealed the cause of the derailment to be a widened track gauge due to the deterioration of the railway sleeper.

It was found that four earlier trains that entered Hung Hom station on that morning before service L094 had also suffered hit marks on their wheels.

Following examination of the train, KCRC staff detected minor cracks in the welding of mounting brackets for some underframe components.

The Environment, Transport and Works Bureau reprimanded the KCRC for not immediately notifying the Government when it found problems with its East Rail trains in 2005.

Secretary for the Bureau Dr. Sarah Liao said she had ordered the KCRC to inspect all its trains, and did not rule out suspending services if there were safety doubts.

KCRC chairman Michael Tien accepted responsibility for the corporation's poor judgement in not sharing the information with the public in a timely matter.

[20] The wide platform gap at several stations (namely Lo Wu, Tai Wo, University, Kowloon Tong, and Mong Kok East) is a safety concern.

[67] The new MTR R-Stock trains have wider compartments than the older East Rail line rolling stock, therefore narrowing the gap.

This would involve the installation of about 1,600 pairs of gates at 13 at-grade or elevated stations along the line, starting from Racecourse and Tai Po Market.

[31] In addition, the Metro-Cammell EMUs lacked an motoring and braking system advanced enough to achieve high accuracy in platform stopping location, which is a prerequisite for APGs operations.

Advance works like platform structure strengthening commenced in 2013, yet the first pair of APGs was not installed until 7 May 2023, one week short of the cross-harbour extension's first anniversary.

[32] A second batch of installation works are expected to commence at Sha Tin, Tai Wai, Lok Ma Chau, and Sheung Shui later in 2023.