The Brunel Saw Mill

The Brunel Saw Mill

A sawmill built between 1810 and 1814, designed by Marc Brunel in collaboration with Jeremy Bentham and Edward Holl, with later extensions added in the mid-19th century. The building is constructed of brick with stone dressings and features a hipped slate roof with corrugated-iron valleys.

The structure follows an I-shaped plan, comprising a central sawmill with a western engine house and chimney, an eastern workshop, and mid-19th-century north-western offices. A ramp leads north from the mill.

The exterior of the single-storey sawmill displays a matching front and back, each with a cornice, parapet and coped end gables to the valley roof. The principal façades feature a nine-window range with round-arched end doorways fitted with radial fanlights. A continuous central range of seven bays uses cast-iron posts supporting mid-20th-century glazing with central double doors. The two-storey and three-storey end blocks have parapets and string courses, with first-floor central doorways and flanking eight-pane over eight-pane sashes on the first floor.

At the southern end of the engine house stands a notably large battered square chimney in three stepped stages, each stage featuring sunken panels divided by ashlar bands. The chimney has clasping buttresses at the base and a round opening extending through its full height. A domed iron pressure vessel stands immediately to the south.

The tall, narrow former offices attached to the engine house feature round-arched windows with early-20th-century casements and flat-headed twelve-pane windows on the second floor, with similar windows to a single-bay north end.

The interior is remarkably unaltered and complete for an industrial building of this period. The sawmill contains timber queen post trusses with prince posts, with those on the north side later strengthened by iron trussing. Cast-iron posts in the basement support a timber floor. The cast-iron frames of the reciprocating saws rise from the basement, some inscribed "John McDowall and Sons, Johnstone". The eastern section features a complete two-storey fireproof frame with cast-iron columns, bridging beams, fishbelly joists and a flagstone floor, topped by a water tank formed of cast-iron plates bolted together. A similar tank exists in the western section above the engine house, with matching fireproof details.

The mill was powered by a Maudslay, Sons and Field beam engine and was connected via canal and tunnel (550 feet long) to the mast pond. Timber was lifted by a floating platform up an oval shaft north of the eastern block, then carried by overhead rail to long ranges of timber stores extending north of the mill. Eight reciprocating saws in cast-iron frames converted logs delivered to the mill into planks, which were subsequently transported to the Timber Seasoning Sheds situated in front of and behind the Mould Loft.

This was the first use of steam power at Chatham and represents the earliest fireproof construction in the dockyards, employing the same structural frame that Edward Holl later used at the Devonport Spinning House and Chatham Lead Mill. The works constitute a notable early example of mechanisation and are part of a fine assemblage of Georgian naval buildings.