Portsmouth Block Mills

They started the age of mass-production using all-metal machine tools (designed chiefly by Marc Isambard Brunel), and are regarded as one of the seminal buildings of the British Industrial Revolution.

The Royal Navy had evolved with Britain's development by the middle of the eighteenth century into what has been described as the greatest industrial power in the western world.

The Admiralty and Navy Board began a programme of modernisation of dockyards at Portsmouth and Plymouth such that by the start of the war with Revolutionary France they possessed the most up-to-date fleet facilities in Europe.

In 1795, Brigadier-General Sir Samuel Bentham was appointed by the Admiralty, the first (and only) Inspector General of Naval Works with the task of continuing this modernisation, and in particular the introduction of steam power and mechanising the production processes in the dockyard.

The Inspector General's office was responsible for the introduction at Portsmouth of a plant for the rolling of copper plates for sheathing ship's hulls and for forging-mills for the production of metal parts used in the construction of vessels.

By 1797 work had started on building additional dry docks and on deepening the basins, and Bentham realised that the existing drainage system would not cope with the increased demand.

This engine was replaced in 1837 by another engine made by James Watt and Co. Space was very tight and expansion of manufacturing facilities was not possible, so by 1802 the drainage basin was filled with two tiers of brick vaults—the lower layer to act as the reservoir, the upper layer as storage, and the roof of the latter being level with the surrounding land, so creating more space.

In 1802 Marc Isambard Brunel proposed to the Admiralty a system of making blocks using machinery he had patented.

The yard between the two wood mill buildings was walled-off and roofed to form a new workshop to house the block-making machines.

Due to Bentham's absence in Russia, it was Goodrich who actually brought the block mills into full production.

At that time there were no milling, planing or shaping machines, and all flat surfaces were made by hand chipping, filing and scraping.

These machines and the block mills attracted an enormous amount of interest from the time of their erection, ranging from Admiral Lord Nelson on the morning of the day he embarked from Portsmouth for the Battle of Trafalgar on 1805, to the Princess Victoria at the age of 12, as part of her education.

Even during the time of the Napoleonic Wars, until 1815 there was a stream of foreign dignitaries and military men wishing to learn.

The sawmills were important since Brunel was enabled to develop his ideas which he employed later in his private veneer mill at Battersea, and the Royal Navy sawmills at Woolwich Dockyard and Chatham Dockyard, as well as mills he designed for private concerns, such as Borthwick's at Leith in Scotland.

The Block Mills have not been in use for many years, although a lot of the original pulley systems remain in situ, albeit in a poor state of repair.