The southernmost arch is semicircular in profile, built from rough voussoirs, those wedge-shaped stones that lock an arch together, while the other two are more segmental, flatter in their curve, their voussoirs similarly rough-cut. The variation is not accidental inconsistency. It is the visible record of a structure that has been partially rebuilt, repaired, and underpinned across different periods, leaving an uneven but honest record of its own maintenance.

The bridge crosses the River Bride and appears by name as Knocknaneirk Br. on the Ordnance Survey six-inch map of 1842, which gives a useful lower bound for its existence in something close to its current form. Measuring 7.2 metres in width, it is a substantial rural crossing. Its history of repair is written into the fabric: the central arch has been patched, and the underpinning visible across all three suggests repeated interventions against the force of the river below. The breakwaters add another layer of this incremental engineering; a low pointed form on the upstream side to deflect the current, and a later rectangular one on the downstream side, each added at different moments as the bridge was persuaded to keep standing. Just to the east, the remains of Hornhill Mill survive, a reminder that this stretch of the Bride was once a working corridor rather than a quiet country crossing.