Red Bridge, Ballyrobert Road, Crawfordsburn, Bangor, Co Down, BT19

Red Bridge is a single-span brick and stone road bridge built in 1852, carrying the Ballyrobert Road from Crawfordsburn across Clandeboye Avenue to the main Bangor-Belfast road. It is possibly the work of Benjamin Ferrey and combines neo-Gothic and Scottish Baronial architectural elements.

The bridge is constructed of red brick with ashlar sandstone detailing. Chamfered and grooved sandstone quoins to the abutments continue as voussoirs around a two-centred arch. A projecting sandstone drip mould sits directly over the voussoirs and continues partway down each abutment. Above this is a single course of sandstone blocks. Recessed square sandstone panels with moulded surrounds sit directly over the arch crown on both faces; the south-facing panel carries the date 1852 in bas-relief, whilst the north-facing panel is obscured by overgrowth but may also bear this date.

The bridge is framed on both sides by rectangular pilasters with stepped sandstone quoins that rise to low circular brick turrets at road level, which also serve as terminal piers to the parapets. The turret bases are carried on moulded sandstone corbels. A moulded sandstone string course runs along the base of the parapets between the corbels. The turrets are embellished with blank sandstone window loops. Parapets are coped with moulded sandstone blocks that continue around the tops of the turrets.

The bridge's plan form is notable: although the road already existed, the bridge is both orthogonal and aligned on the avenue, maintaining its straight course while being wide enough to allow the road to run straight across it. This design solution avoided the expense of a skew bridge and the creation of a dogleg in the avenue below.

The present road is shown on the 1834 Ordnance Survey six-inch map. However, Clandeboye Avenue between Helen's Bay and the Clandeboye Estate was not laid out until the early 1850s, designed by landscape architect James Fraser for the 1st Marquis of Dufferin & Ava. This bridge, an entirely new construction on the existing line of the road, is marked as "Viaduct" on the 1858 map and as "Red Bridge" from the 1900 edition onwards. Its unusual brick construction (rather than the stone typical of bridges of this period) gives it its name. The bridge is similar in style to Benjamin Ferrey's early 1860s railway bridge at Helen's Bay Station and a road bridge of 1853 just north of that station, also possibly by Ferrey.

The bridge's historical significance derives from its link with the Clandeboye Estate and Helen's Bay railway station structures. The carriageway runs at an angle across the bridge and comprises a two-lane road and footpath. A private garden occupies the space between the edge of the road and the parapet on the south side, whilst the corresponding space on the north side is heavily overgrown. Clandeboye Avenue is now a public footpath between Helen's Bay and the Clandeboye Estate, accessible from the road via a track at the north-west end of the bridge.