Breen bridge over Mourne River, (former railway bridge), Camus & Breen TD, Strabane, Co Tyrone

Breen Bridge is an early twentieth-century riveted iron and steel girder railway bridge carrying the former Londonderry & Enniskillen Railway (later the Great Northern Railway) over the Mourne River. The bridge was erected around 1910 as part of a series of improvements to the railway line, though the piers and abutments likely date from the original mid-nineteenth century bridge. It represents a significant advancement in structural engineering technology, driven by the need to accommodate improved rolling stock.

The bridge is a four-span structure aligned north-south, consisting of a trough of riveted iron sheets supported on steel girders spanning between bull-nosed piers. The piers project to either side as cutwaters and are faced in uncoursed squared stone. The abutments are similarly constructed in rock-faced stone with ashlar coping, built into steep banks at either side. The deck is cantilevered over the girder frame and bounded by steel rail parapets punctuated by a series of pedestrian refuges. The trough is infilled with earth and is now grassed, the track having been removed. A rock-faced stone pier with ashlar coping remains to the south, partially covered with vegetation. The bridge spans the Mourne-Beg River in an unspoiled rural setting with grassed banks and open pasture to either side.

The Londonderry & Enniskillen Railway Company was incorporated in 1845 and constructed a single-track line extending southwards from Londonderry, reaching Strabane by April 1847. The line subsequently extended to Omagh by 1852, Fintona in 1853, and Enniskillen in 1854. Although the original line faced early commercial challenges from competition with the Strabane Canal and Foyle Navigation, the railway eventually brought significant commercial advantages to the towns it served and the surrounding agricultural lands. The Londonderry & Enniskillen Railway was leased to the Dundalk & Enniskillen Railway Company in 1860, subsequently becoming the Irish North Western Railway Company. Following a series of amalgamations, it merged with the Ulster Railway Company in 1876 to form the Great Northern Railway Company (Ireland).

The original timber bridges erected by the Londonderry & Enniskillen Railway Company around 1850 were replaced by cast-iron girder trellis bridges, which in turn were themselves replaced in 1910-11 by the present enclosed troughs of riveted iron sheets supported on massive steel girders. Breen Bridge is one of the notable examples of this 1910-11 replacement programme. The railway system subsequently faced increasing competition from road transport. In 1953 the Great Northern Railway ceased to exist as an independent company and was acquired jointly by the governments of Northern Ireland and the Republic of Ireland. In 1958 the greatly diminished portion of the former Great Northern system within Northern Ireland passed under the control of the Ulster Transport Authority, leading to a period of contraction in which many unremunerative lines were closed. The bridge enjoys group value with other vestigial remains of the railway, notably with Camus Bridge, with which it shares constructional detailing.