GILLINGHAM TQ7669NW DOCK HEAD ROAD, Chatham Dockyard 686-1/1/56 (South side) 06/06/84 Boilershop GV II* Dry dock cover, now boilershop, disused. 1847, by Fox Henderson & Co at Woolwich Dockyard, re-erected at Chatham c1876. Cast- and wrought-iron frame with corrugated-iron cladding and roof. PLAN: rectangular with lower aisles. EXTERIOR: single-storey; 11-bay range and 3-bay W extension. Gabled ends with raking aisles, frame expressed externally, with louvred ridge and moulded gutters. Irregular scattering of small windows to sides. Lower side brick additions along sides. A decorative square clock tower at the W end with clocks to each face, and a louvred octagonal cupola and finial. INTERIOR: a rigid iron frame has cast-iron columns to wrought-iron roof trusses, and aisles with segmental-arched cast-iron braces with pierced spandrels. HISTORY: covers for ship-building dry docks were introduced in c1814 to protect wooden ships during construction against the weather. The original building was cast and erected at No.4 slip, Woolwich, and re-erected at Chatham by convict labour after Woolwich closed in 1865. It represents a significant step forward in the development of rigid metal-framed structures, and 'established the principal of (portal) bracing through stiff joints',(Sutherland). A fine group with the No.8, Machine Shop (qv), moved at the same time from Woolwich, and the timber and metal slip covers in Chatham Dockyard (qv). (The Buildings of England: Newman J: West Kent and the Weald: London: 1976-: 207; The Newcomen Society: Sutherland R J M: Shipbuilding & the Long-Span Roof; Paper read at Science Museum: 1989-: 16). Listing NGR: TQ7639969945