Botterham bridge and locks with adjacent circular weir

A canal bridge, two-lock staircase and circular weir c.1770, designed by James Brindley.

MATERIALS: the bridge and lock chambers are constructed of red-orange bricks laid in English bond with blue brick and ashlar dressings. The lock gates have timber balance beams and iron gears.

PLAN: the lock chambers are arranged along a north-south axis and are rectangular on plan with splayed flanking walls at either end. The weir to the west of the upper lock is circular on plan.

DESCRIPTION: the lock staircase is composed of two lock chambers with three lock gates. The lower gate of the upper lock forms the upper gate of the lower lock. The upper lock chamber is closed at its head with a single gate and there are double gates to the head and tail of the lower lock, all with balance beams. The iron paddle gear at the top lock is reused from the Birmingham Canal Navigation. The lower gates have modern beams and mechanical gears.

The lock chambers and gate quadrants are paved with red and blue engineering bricks and have diamond-patterned pavers to the waterside edges. The lower lock chamber has a brick overflow weir arcing from its east side and rejoining the canal to the south. There is a shallow cast iron footbridge with low latticed sides spanning the lower lock to the south of the lower gates. The circular weir to the west of the upper lock has a low brick parapet with half-round coping and central domed cage.

The bridge is orientated roughly east to west and crosses the lower lock from the south end of Botterham Lane to reach the tow path running along the west side of the canal. The south side of the bridge has a ramped parapet with half-round coping which curves south and slopes down to the edge of the lower lock chamber. The upper courses of brickwork appear to have been rebuilt. There is a cast iron bridge plate to this elevation that reads ‘Botterham/ No. 42/ Bridge’. A barrel vaulted tunnel passes through the bridge which has quoined imposts supporting brick voussoirs and a stone hood band. The north side of the bridge is at the same level as the upper lock chamber and there is a low engineering brick wall between the middle lock gates and bridge.