The Midland Great Western Railway (MGWR) was the third largest Irish gauge () railway company in Ireland. It was incorporated in 1845 and absorbed into the Great Southern Railways in 1924. At its peak the had a network of , making it Ireland's third largest network after the Great Southern and Western Railway (GS&WR) and the Great Northern Railway of Ireland.
The served part of Leinster, County Cavan in Ulster and much of Connacht. Its network was entirely within what in 1922 became the Irish Free State.
The (8 & 9 Vict. c. cxix) received royal assent in July 1845, authorising it to raise ã1,000,000 capital and to build a railway from Dublin to and , and to buy the Royal Canal. Construction of the main line began from Dublin in January 1846 and proceeded westwards in stages, supervised by chief engineer G. W. Hemans. It opened from as far as Enfield in May 1847, to in December 1847 and to Mullingar in October 1848.
Rivalry existed between the and the , each of which wanted to build the line to . The extended its line from Mullingar and the from its line at . The was first, going via and reaching Galway, from Dublin, in August 1851. It was not until 1859 that the reached Athlone. The was obliged to operate its service over track between Athlone and Galway, paying the 65% of passenger and 55% of goods receipts. The retained a separate station, which is now the sole operating station, as the last service to the station ran on 13 January 1985. The branch is to be made into a rail trail as part of the Dublin-Galway Greenway by 2020.
In 1890 the government granted the ã264,000 to build a railway to Clifden on the Atlantic coast of County Galway. It opened as far as Oughterard in January 1895 and to Clifden in July 1895. Due to its inland route, it did not serve the bulk of the area's population, so the closed it in 1935.
A similar branch line was built at the same time from Westport to Achill on the Atlantic coast of County Mayo. The built the first section, opening it as far as Newport in February 1894 and Mulranny in May 1894. The Board of Works built the section from Mulranny to Achill, which opened in May 1895. The closed the line in 1937.
At its peak the had a number of branch lines:
In 1924 the Oireachtas of the Irish Free State passed the Railways Act 1924, which that November merged the with the Great Southern and Western Railway (GS&WR), Cork, Bandon and South Coast Railway to form the Great Southern Railway. In January 1925, that was joined by the Dublin and South Eastern Railway to form the Great Southern Railways (GSR).
Locomotives and rolling stock were maintained at 's Broadstone works in Dublin.
The painted all of its locomotives bright emerald until about 1902, when the first of the new Class A 4-4-0 express locomotives were outshopped in royal blue. This did not wear well and in 1905 the company adopted grass green. From about 1913 locos were painted gloss black until the became part of the in 1925. From then on, all locomotives were gradually repainted plain unlined dark grey.
Passenger coaches were finished in varnish or brown paint until the blue livery was introduced in 1901. As on the locomotives this weathered badly and from 1905 the reverted to brown, which after 1910 was not so well-adorned with lining. From October 1918 coaches were painted a very dark Crimson and after 1924 the used a similar shade for some years.
No locomotive has been preserved but 6 carriages and a tanker exist.
Those of the former 's main lines that are still open are owned and operated by Iarnród ÃÂireann. Routes between Dublin and Sligo, Athlone and Galway, Athlone and Westport and the Ballina branch remain open to passenger traffic. The Meath on Track campaign is campaigning to have the Navan â Clonsilla line (not to be confused with the former GNR Navan â Drogheda line) reopened earlier than the 2030 date announced under current Iarnród ÃÂireann policy. The Edenderry, Clifden, Achill, Cavan, Killeshandra, Ballaghaderreen branch line, Ballinrobe, Killala and Loughrea branches lines are all closed.
Rail Users Ireland proposed running some Galway â Dublin services via the station in and the disused route via to Mullingar, reinstating the route of the first service via the former line. The current Galway service runs from . Despite the opening of the Dublin-Galway greenway on the route, calls have continued from local representatives to reopen the line.
Three former stations are now hotels, two of which are called the "Station House Hotel" but are unconnected by ownership. They are the expanded former Clifden station in County Galway, Kilmessan Junction in County Meath and the Mullranny Park Hotel at Mulranny, County Mayo.
The Great Western Greenway is a greenway rail trail that uses the route of the former Westport â Achill branch line.
<small>This position was not always filled.</small>