Millwrights Shop (Building So66) At Devonport Dock Yard

Millwright's Shop (Building SO66) at Devonport Dockyard, Plymouth

Former millwrights' shop, now offices. Built 1834–1837 to the designs of George Ledwell Taylor, architect to the Navy Board, with late 19th or early 20th century alterations and a late 20th century addition.

The building is a two-storey cast iron framed structure faced with Plymouth limestone ashlar. It has a rectangular plan of five by nine bays, with clasped pilasters to the corners, a plat band to the parapet, and a hipped corrugated iron roof topped with a stone parapet. The west elevation features a plat band over a double doorway in the second bay from the right. The remaining bays each have tri-partite metal-framed windows with small panes, thick mullions and a central transom to the ground floor. There are nine windows to the first floor, each with central-hung metal-framed casements with square-headed architraves set to the cill band. Similar windows appear on the return elevations. The south elevation is now obscured by a circa 1980 office block addition, built on a slightly different alignment and of no special interest.

A single storey ashlar structure was added against the east end of the north wall in the late 19th or early 20th century and probably formerly linked the Millwrights' Shop with the adjacent North Smithery. This addition is considered of lesser interest than the two principal buildings.

The southern two-thirds of the ground floor originally contained heavy plant machinery. The northern third comprised, from west to east, the drilling shop, engine houses in the centre containing pumping and rotative engines, and the boiler house to the rear. Light turning and pattern-making work, models and plans were located on the first floor. All machinery has been removed and the interior has been converted to offices with the addition of internal partitions. The first floor is supported by stone corbels, cast iron columns, girders and braces, and cast iron flanges at each corner. The columns rise through the building to support the timber king post roof, which has been retained.

The Millwrights' Shop was designed as part of the modernisation of Devonport Dockyard during the transition from sail to steam and from wooden to iron ships. Designated for the Boiler House when built, it was constructed to house steam-powered lathes, planing, shearing and bending machines used for boiler manufacture and engine repairs, sited adjacent to the forges and furnaces of the North Smithery. Two steam engines were installed: one to replace the horse engines formerly used for pumping the dry docks and blowing air into the forges of the North Smithery, and another to power the drilling machines, lathes, boring machinery and grindstones. Steam-powered engineering shops for the navy were first established at Portsmouth in 1829, making this an early and pioneering example. By the mid-19th century, work at Devonport declined as resources were switched to Woolwich, leading to the eclipse of this innovative workshop.