Monkstown Bridge, Monkstown Road, Monkstown, Co.Antrim

Monkstown Bridge is a twentieth-century reinforced concrete bridge carrying Monkstown Road over the Belfast to Antrim railway. Built around 1931 by the London, Midland and Scottish Railway Company (Northern Counties Committee), it formed part of the 'Greenisland Loop' scheme, a significant railway infrastructure project that eliminated the need for trains travelling to Antrim to reverse at Greencastle, shortening the journey by approximately 2.5 miles. The loop line opened in 1934 and remained in regular passenger service until 1976.

The bridge is a shallow segmental single-span structure expressing a restrained Art Deco aesthetic. It features smooth concrete walls and spandrels with a projecting plinth base to the parapet. The design includes a pair of full-height concrete piers at either end, detailed with Art Deco-style stepped detailing and vertically fluted panels to the outward faces. The parapet wall is fluted concrete with a smooth finish to the road surface and smooth concrete coping. The bridge carries a bituminous road surface and a pair of bituminous footpaths with concrete kerbing.

The bridge does not appear on the 1931 Ordnance Survey map, where the road is shown crossing or passing under the railway at Monkstown Station. It is recorded on the 1955 Ordnance Survey map carrying the road over Monkstown Halt. The scheme was directed by the Northern Counties Committee's resident engineer W.K. Wallace, and several other reinforced concrete bridges were erected as part of the same initiative, including those at Bleach Green Junction, Jordanstown Road, Jennings Park, Auld's Bridge, and Mossley, between 1931 and 1933.

The bridge was substantially rebuilt in the mid-1990s, including widening works, replacement parapets, and new buttresses. These alterations have seriously compromised its original fabric and integrity. The railway line, though closed to regular passenger traffic, remains in periodic use for goods trains, with plans for passenger service reinstatement pending completion of the Central-York Street station linkup.