The Belfast and County Down Railway (BCDR) was an Irish gauge () railway in Ireland (later Northern Ireland) linking Belfast with County Down. It was built in the 19th century and absorbed into the Ulster Transport Authority in 1948. All but the line between Belfast and Bangor was closed in the 1950s, although some of it has been restored near Downpatrick by a heritage line, the Downpatrick and County Down Railway. History The company was incorporated on 26 June 1846 with the first section of line from Belfast to Holywood opening for traffic on 2 August 1848. The line was further extended to Bangor by the Belfast, Holywood and Bangor Railway (BHBR), opening on 1 May 1865, and acquired by the BCDR in 1884. The line to Downpatrick was opened on 25 March 1859. The line from Downpatrick to Newcastle was built by the Downpatrick, Dundrum and Newcastle Railway, opening on 25 March 1869 and absorbed by BCDR on 14 July 1884. The railway's first chief engineer was Sir John Macneill, who was responsible for allowing the railway to cross the marshy River Quoile. A branch to Ballynahinch was opened in 1858 via Ballynahinch Junction. A branch line from Downpatrick to Ardglass was opened in 1892, as was a loop line at Downpatrick. This resulted in a 'triangle'-shaped track layout just outside of Downpatrick, allowing trains between Belfast and Newcastle to collect and drop off passengers at the Loop Platform, who would be ferried between there and the main station at Downpatrick by a local train. Thanks to the triangular layout, trains were still capable of operating directly from the main Downpatrick station to Belfast or Newcastle. The branch from Newcastle to Castlewellan was opened on 24 March 1906. By 1948 the company had 29 locomotives. Two steam railcars from Kitson & Co. were acquired in 1905. The locomotive works were at Belfast Queen's Quay railway station and closed in 1950. New carriage works had been opened in 1886, with the last carriage being built in 1923. Routes Belfast (Queen's Quay) – Ballymacarrett Halt – Victoria Park – Sydenham – Tillysburn – Holywood – Marino – Cultra Halt – Craigavad – Helen's Bay – Carnalea – Bangor West Halt – Bangor Belfast (Queen's Quay) – Bloomfield – – Knock – Dundonald – Comber Comber – Ballygowan – Shepherd's Bridge Halt – Saintfield – Ballynahinch Junction – Crossgar – King's Bridge