The first part opened in July 1877 and regular passenger services began in August 1878, the first on the Irish 3 ft (914 mm) gauge railways.
From east to west, the railway ran for 32 miles (51 km) between Larne and Ballymena via Kilwaughter, Headwood, Ballyboley, Ballynashee, Collin, Moorfields, Kells and Harryville.
[1][page needed] From Larne, the line rose for 12 miles (19 km) to a summit of 660 feet (200 m) at Ballynashee.
Following World War I, the line experienced a further decline in mineral traffic and increasing road competition.
These carriages were arguably the most comfortable and modern ever built for an Irish narrow gauge line, including steam heating, electric lighting, lavatories and corridor connections between the coaches.
This followed the closure of a paper mill at Ballyclare, which had supplied much of the line's remaining freight traffic.