The manufacturing side of Chatham dockyard underwent considerable change during the years 1815 to 1865. At the outset of this period it was heavily dependent on muscle power, with no operating steam engines installed in any of the centres of manufacture. By 1865, all but a few specialised crafts had witnessed the impact of steam. Also, the nature of materials under manufacture was changing [173, 191] with new factories and workshops, designed from the outset to make full use of steam- powered machinery, beginning to operate [163, 190]. However, development during this period was piecemeal, lacking overall and co-ordinated planning [195].

The revolution in steam was already forging ahead in 1815, with construction underway of Marc Brunel's mechanically powered wood mills. The building work was mostly undertaken by the yard's work force [155]. Upon completion, the mills transformed the process of timber plank manufacture, able to process quantities from a variety of types of timber at considerable speed [172] both for Chatham and other yards [152, 171]. As a result, only a small number of sawyers were retained, these either on a reduced rate of pay, undertaking work in connection with the operation of the mill or carrying out tasks too complex for the saws of the wood mill [196]. Although designed by Marc Brunel, the man responsible for overseeing the completion of the mill was a mr ellicombe, upon whom Brunel placed much trust [148]. However, on the appointment of a Master Sawyer of the Mills [144], Ellicombe was considered by the Commissioners at the Navy Board as surplus to requirements [146, 147, 149]. The totality of the finished design, encompassing not only eight sets of circular powered saws but also a canal for the easy movement of newly arrived timber and an overhead rail system which directly connected the mill to an area for the storage of planks, attracted visiting dignitaries [145] and much published praise [150, 184]. Not surprisingly, it was subject to an inspection by the Commissioners of the Navy Board shortly after its completion [164].

Having been designed to meet the demands of the war-time navy, the wood mills were soon producing more sawn timber than required, leading to part of the building being considered for conversion to storage [157]. The upper floor accommodated a duplicate set of the block-making machines [142, 143] – Brunel's other contribution to britain's naval dockyards.