Randalstown Bridge, Bridge Street, Randalstown, Antrim, Co Antrim

Randalstown Bridge is a nine-arched masonry bridge carrying the main Antrim to Randalstown road over the River Main on the eastern approach to Randalstown. It is probably of 18th century foundation, built between 1760 and 1779, though its exact date of construction is not known. The bridge is shown on the Ordnance Survey map of 1829, and historical records indicate it was widened in 1816, 1834, and 1864, with improvements made in the 1930s. An 1830s Ordnance Survey memoir described it as "a clumsy old structure and must be of some antiquity as it seems to have been twice widened," noting it was "formerly very narrow" and measuring 193 feet in length and 29 feet in width between the parapets.

The bridge is constructed of random rubble basalt with rough stone voussoirs to segmental arches. It has a slight hump-backed form, with the central arch being slightly higher than the others. The two end arches at the east accommodate a mill race, while the third arch from that end is dry in normal circumstances, coinciding with a spit of land dividing the mill race from the main river. The piers on both faces have angled cutwaters to arch springing level. The spandrels and arches are inset slightly from the line of the abutments. Parapets on both faces are topped with copings of roughly squared flat blocks; part of the parapet on the south side is damaged with some copings missing.

Later alterations include reinforced concrete strengthening of the end arch at the west end on the north face, and near-complete blocking of the end arch at the east end on the north face in the course of building a reinforced concrete culvert. On the south face near the east end, a later buttress of rubble masonry has been formed from a cutwater. Modern pipes have been carried through the cutwaters on the south face across the length of the bridge, with a second pipe running parallel supported on concrete uprights. The carriageway is laid with tarmac, with a footpath running along the south side.

The bridge stands within the built-up area of the town, alongside a much taller mid-19th century railway viaduct which runs at an angle on the south side. The approach road at the east end runs under this viaduct. Together with the railway viaduct, the bridge forms an interesting group. Despite its later alterations and additions, it retains its original character and enjoys a largely unspoiled setting. The bridge is of industrial archaeological interest and is located within a conservation area.