Former Galvanising Shed (Visitor Centre)

The former galvanising shed, now a visitor centre, dates from the mid-19th century and was altered around the 1980s. It is constructed of brick with stone dressings and features a slate roof, designed in an Italianate style with a rectangular plan.

The exterior is a single-storey structure with a 12-bay range. The gabled ends are coped and have raised centres flanked by pilasters. There is a cambered-headed boarded vehicle entrance, with round-arched windows on either side that are blind below the springing, and a large central round-arched window with diagonal and central keys. The sides of the building are divided by flat-headed recesses that also contain round-arched windows. The roof has a raised louvred ridge.

Inside, the building features metal roof trusses and a gantry crane supported by central posts. Historically, galvanised corrugated sheet metal, which was patented in 1825, became increasingly popular for enclosures starting in the 1840s, with the Admiralty Works Department being pioneers in its use for slip roofs. By the 1840s, slip roofs were covered in zinc-plated sheet iron, leading to a rise in the use of corrugated iron in naval yards. This building is part of the dockyard's development alongside the No.1 Smithery and is associated with the mid-19th century increase in the use of iron for buildings and warships.