After leaving Botanic the line reaches Belfast Lanyon Place, a major interchange station which opened in 1976.

The Bangor Line diverges shortly after leaving Lanyon Place, with services to Derry and Larne crossing the Dargan Bridge, also known as the 'Cross Harbour Link' which opened in 1994.

Previously between 1978 and 2001, the line between the Bleach Green viaduct and Antrim was closed, and services to Derry operated via Crumlin, Glenavy, Ballinderry and Lisburn.

This section of railway is now used solely for driver training or other operational requirements e.g. special services to major events.

[citation needed] The Dargan Bridge is single track, with a passing loop located on the west bank of the Lagan, just before arriving into York Street which opened in 2024 replacing Yorkgate station.

NI Railways refrain from allowing more services to stop at Whiteabbey to help reduce journey times to Derry/Londonderry.

On the single-track section between Mossley West and Antrim, the line reaches its maximum operational speed of 90mph.

[citation needed] The line from Antrim to Coleraine is single-track, with passing loops at Magherabeg, Ballymena, Killagan and Ballymoney.

[citation needed] Ballymena opened in 1848, however the current building dates back to 1982 during a modernisation programme by NI Railways.

The shared train and bus station building has a distinctive rotunda with a high arched entrance, by GM Design Associates.

[citation needed] The line has two platforms, with three sidings, which typically hold trains during the night to operate early morning through services to Belfast Grand Central.

Leaving Coleraine, the Portrush Line diverges to the right, with services to Derry/Londonderry continuing over a bascule bridge over the River Bann.

The line continues through to Caslterock, the station opened on 18 July 1853 and was built to a design by the architect Charles Lanyon.

[citation needed] The down platform, despite receiving a complete refurbishment two years prior, has now been taken out of service and the track lifted.

The original Londonderry Waterside Station was opened on 29 December 1852 by Steven Alfred John Campbell, a well-known banker of the time.

[citation needed]On 6 October 2016, Translink confirmed that the railway would be returning to the former BNCR Waterside station which will be used as a new transport hub for the city.

[citation needed] Derry/Londonderry has the longest platforms on the NIR Network, at 258.3 metres in length[citation needed] Weekday and Saturday services on the line operate hourly from Belfast Grand Central to Derry~Londonderry (and vice versa), with most trains running the full route.

On weekdays (Monday–Friday), 20 northbound trains per day (tpd) operate between Belfast Grand Central and Coleraine, with 16 continuing to Derry~Londonderry.

Late-night and peak-time services on weekdays and Saturdays occasionally start or terminate at Coleraine or Lanyon Place to manage demand.

Phase 1 saw the line close for nine months to completely relay two sections (Coleraine to Castlerock; and Eglinton to Derry), extending the life of the remaining section by converting the jointed track to continuous welded rail, elimination of wet spots, and essential bridge repairs.

This was completed by 2013, and timetable changes resulted in a morning train reaching Derry before 9 a.m. for the first time since Northern Ireland Railways took control of the network in the 1960s.

Due to capacity issues on the line, Northern Ireland Railways announced they would be purchasing 21 extra carriages from Spanish manufacturer CAF.