Former Sawmill, Building Numbers 105, 106 and 107

Former Sawmill, Building Numbers 105, 106 and 107

Steam-powered sawmill, fire-engine house and store, now workshops and offices. Built 1856-58 by Colonel G T Greene for the Admiralty Works Department, with ironwork by Fox, Henderson. The boiler house was raised around 1860. The buildings are constructed of yellow stock brick with a slate roof and iron frame.

The complex has a square plan with the main sawmill flanked by a parallel northwest engine house and southwest boiler house with attached chimney, and an east junk store with fire engine houses at both ends. The structures comprise two storeys, an attic and basement, distributed across an eight-bay sawmill, a 4 by 10 bay junk store, a 2 by 3 bay boiler house, and a 1 by 3 bay engine house.

The main sawmill block is parapeted with wide clasping buttresses and two shallow gables at each end. Cobbled ramps lead up to full-width cast-iron doorways (some with later infill or replacement doors), with upper small-paned iron tilting casements above. The first floor has six segmental-arched casements in matching recesses, and the attic features large tripartite lunettes in similar recesses. The beam engine house is set back with round-arched ground floor openings to the end and sides, and a heavy granite bearing pad set into the lower side wall. Its upper level has segmental-arched casements and a later iron water tank on top. The boiler house to the southwest is one bay wider, with a round-arched cart doorway containing double doors in the west end, a thin plat band and cornice, and two late 19th-century ground floor windows. A battered square chimney stands at the northwest end. The fire engine houses project either end of the junk store beyond the sawmill, with matching pedimented ends, five-bay cast-iron ground-floor doorways and windows (all but one bay in the west end bricked up), a segmental-arched window to the side, and similar casement windows to the first floor; a blocked oculus appears in each pediment. The inner side returns have round-arched doorways with overlights and fanlights, leading to the stairs. The southeast elevation features an arcade of nine wide, recessed round-arched ground-floor windows (formerly open) and doorways at the east end and three bays in, a single casement window at the west end, and segmental-arched first-floor casements.

Internally, the sawmill is divided into seven aisles by an iron frame of large round tapering columns with T-section lateral and transverse beams with parabolic bottom flanges, attached at the columns with shrink rings, and T-section fish-belly joists which rest on the upper surface. The upper floor contains slender iron posts supporting wide composite wrought-iron trusses with diagonal braces and cast-iron struts, representing an advanced Greene design. The northwest room has multiple bracing to its hipped roof, executed in the manner established by the Rennies at the Royal William Yard in Plymouth in the 1830s. The fire-engine houses contain cantilevered stone dogleg stairs with iron stick balusters at either end. The junk store has an internal iron frame, divided on the first floor by mid-20th-century partitions. The boiler house retains circa 1860 riveted lateral beams with transverse beams and joists matching the sawmill pattern.

This was a large steam-powered sawmill replacing the hand saw pits in Building 23, powered by a pair of rotative beam engines. Its design and structural system are almost identical to the contemporary South Saw Mill at Devonport, and contrast with the more innovative system Greene employed for the nearby Boat Store, built two years later. This difference reflects the greater stresses imposed by sawing and demonstrates the understanding of metal framing at the time the Boat Store was built. The basement housed the machine foundations, notably the curvilinear saw frames set deeply to withstand severe vibration, along with shafting and belt drives. The building is included for its historic interest and as part of a group with Building 23 (the former sawyers' shop) and the Boat Store within a unique planned early 19th-century dockyard.