Gunboat Yard boundary walls, watchtowers and gates

Gunboat yard walls, watchtowers, and gates, 1856.

ARCHITECT: the design of the gunboat yard was by the Admiralty Works Department, under Colonel Greene, the Director of Works and William Scamp, the Deputy Director of Engineering and Architectural Works. The brickwork was entrusted to Messrs Rigby of London.

MATERIALS: red brick laid in Flemish bond. The watchtowers have slate roofs and stone cills, and the gate piers have limestone dressings.

PLAN: the walls enclose the gunboat yard on the south-east and north-east sides, and on the south-west side they survive but now form the south-west elevation of No 1 Ship Tank, built for the Admiralty Experiment Works in 1886 and extended in 1957. There are three watch towers: one at the walls’ junction, the other two at the north and south extremities. The main gates are in the centre of the north-east wall. There are two inserted gateways on the south-east wall, and there is a break in the walls at the point of the engine house complex. At the southern corner the walls extend to form an entranceway to the former burial ground.

ELEVATIONS: the walls are c4m high and have regular recessed panels along their length; occasional ramps (curved steps to the coping) adjust the wall height according to the topography. There is a projecting course of brick along the top, upon which canted brick forms the coping.

The main gates have a pair of substantial pedimented sentry posts forming gate piers on either side of the entranceway. Each is hollow and has a slit window in order for a guard to see out. Between the posts is a round-arched opening, blocked on the north-west side. On the inside elevation are various recessed arches for sentries.

The two blocked secondary gates on the south-east elevation have narrower square piers with stone bands and overhanging stone pier caps. The early C20 entrance is canted back from the line of the wall, and has square piers with pyramidal stone caps.

The burial ground entrance is built in the same style and has curved walls recessing from the road. The central opening has been blocked.

The two-storey watchtowers are square in plan with outward facing round-arched slit windows on each storey. They have a brick corbel table and pyramidal roofs. On the inner walls the towers have segmental arched openings to the ground floors. Flights of steps are built along the walls, with short sentry walks leading the upper floor of the towers, and creating arched shelters below.