Walkmills Bridges, 157 Drumsurn Road, Limavady, Co Londonderry, BT49 OPE

Walkmills Bridges

Two cut sandstone bridges standing on Drumsurn Road on either side of the entrance drive to Walkmills farmhouse, forming important surviving elements of the convoluted mill race system for Walk Mills. The mill race of the cloth mill was diverted upstream of a tributary river to increase the head for the flax mill. Even with this engineering, the mills had to be operated on separate days. The bridges represent an interesting piece of industrial archaeology.

The south-eastern bridge is a very low segmental arch over the former mill race, with the head of the arch sitting only 500 millimetres above the base of the stream. The voussoirs are carefully cut to fit the curve. There is no visible sign of the bridge from the road above, and the stonework on the north-east side is badly damaged by vegetation growth.

The north-western bridge, positioned upstream of the entrance road, is unusually well constructed for a small bridge. It comprises a single segmental arch spanning 2 and a half metres, with springing approximately 3 metres above an unnamed tributary of the Castle River (which served as the mill race for the former flax mill). Built from cut ashlar sandstone, the bridge demonstrates considerable architectural care and quality more normally associated with estate buildings. On each side, the springing stone of the arch has been returned and projects from the face of the structure as the head of a simple pilaster. Two metres above the arch, a coping stone sits below road level and projects outward. On the upstream (north-east) side, the coping gracefully drops on each side as the face of the bridge curves out to flank the stream. There is no parapet at road level; pedestrians are protected by a modern timber fence.

Ordnance Survey Memoirs from 1831 describe a bridge with two arches in Ballymully townland, measuring 12 feet wide and 4 and a half feet high for one arch, and 6 feet wide and 3 and a half feet high for the other. This bridge lay on an accommodation road running north and south through the centre of the parish, now known as Drumsurn Road. However, the present line of the road differs from that of the 1830s, which ran much closer to the buildings. The 1848 Ordnance Survey Map shows the present road line dotted, indicating the change was in contemplation at that time. The present bridges likely date from the 1850s. The late construction date partly explains the care taken in their construction. An additional reason for this quality is the proximity of a sandstone quarry that provided stone for much of the regional housing.