Track gauge in Ireland
The track gauge adopted by the mainline railways in Ireland is. This unusually broad track gauge is otherwise found only in Australia, in the states of Victoria, southern New South Wales and South Australia, as well as in Brazil.
The Grand Duchy of Baden State Railway used this gauge between 1840 and 1855, as did the Canterbury Provincial Railways in New Zealand, until conversion to the gauge in the 1860s. The Launceston and Western Railway in Tasmania also used this gauge from 1871, until conversion to gauge in 1888.
Different gauges
[Image:KilbrickenRailwayStn.jpg|thumb|left|300px|Irish-gauge railway at Kilbricken, on the Dublin–Cork railway line]Ireland's first railway, the Dublin and Kingstown, was built to . The Ulster Railway, taking the Irish Railway Commission's advice, used. The Dublin and Drogheda Railway was proposed to be built to gauge on the grounds of lower costs. The two broader gauges were not used anywhere else. Following complaints from the UR, the Board of Trade investigated the matter, and in 1843 decreed the use of.
This gauge was given legal status by the Regulating the Gauge of Railways Act 1846, which specified for Great Britain, 5ft 3in for Ireland.
The UR was re-gauged in 1846, at a cost of £19,000, and the Dublin and Kingstown Railway in 1857 for £38,000.
The Hill of Howth Tramway and the Dublin and Blessington Steam Tramway also adopted the gauge. Dublin's Luas tram system, opened in 2004, uses.