Royal Arsenal Armstrong Gun Factory

A gun foundry and turning shop, dating from 1856 and constructed between 1855 and 1863 by engineer David Murray, in association with Sir William Armstrong. The building was altered in 1911. It is constructed of polychromatic English garden wall bond brick, with yellow brick detailing and black and orange dressings, and incorporates a cast-iron internal frame and a hipped roof with ridge vents.

The building follows an H-plan, featuring a central porch and a rear courtyard enclosed by an arcade rebuilt in 1911. Externally, the building is in an Italianate style, arranged as a 4:6:3:6:4 bay range. It has projecting end wings, a red brick plinth, modillion impost bands, a dentil cornice, and a parapet (added in 1911). The central porch features wide outer buttresses, a round-arched doorway with alternating red and yellow voussoirs, a blocked fanlight, and steel doors. Gauged brick keyed round-arched windows are located below the impost band, featuring timber frames with roundels at the glazing bar crossings. Tall round-arched windows with metal frames are present in the flanking ranges, along with cast-iron plates with dentils set within the brick impost band. The returns are symmetrical 9-bay ranges, with the central bays set forward to form the entrance.

The interior features an axial row of heavy rectangular-section panelled cast-iron columns in the end ranges, originally supporting gantry cranes. Upper round columns are connected by segmental-arched cast-iron ties, which carry rolled iron roof trusses with king and queen ties. Similar columns formerly extended along the main range.

Historically, Armstrong developed a method for manufacturing stronger rifled gun barrels, which were subsequently adopted by the army and navy and produced under licence at Woolwich. This building served as the gun turnery, with gantry cranes along aisles either side of the columns; the adjoining forge has since been demolished. The building is an impressive example of Ordnance architecture, reflecting the Baroque tradition established by the Ordnance Board in the 18th century, and is a significant structure in the history of British ordnance.