Great Southern and Western Railway

The Great Southern and Western Railway (GS&WR) was an Irish gauge (1,600 mm (5 ft 3 in)) railway company in Ireland from 1844 until 1924. The GS&WR grew by building lines and making a series of takeovers, until in the late 19th and early 20th centuries it was the largest of Ireland's "Big Four" railway networks. At its peak the GS&WR had an 1,100-mile (1,800 km) network, of which 240 miles (390 km) were double track.

The core of the GS&WR was the Dublin Kingsbridge – Cork main line; Ireland's "Premier Line", and still one of her most important main line railways. The company's headquarters were at Kingsbridge station. At its greatest extent the GS&WR included, in addition to the Dublin – Cork main line, the Dublin – Waterford and Mallow – Waterford lines and numerous branch lines.

Dublin – Cork Main Line

William Dargan, Ireland's foremost railway contractor, built much of the GS&WR's main line and a number of its other routes.

Construction of the Dublin – Cork main line began in January 1845. The project included a branch line to Carlow, which was completed in August 1846. In July 1848 the main line reached Limerick Junction, where it met the Waterford and Limerick Railway and thus linked Dublin and Limerick by rail.