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The Portsmouth Block Mills form part of the Portsmouth Dockyard at Portsmouth, Hampshire, England, and were built during the Napoleonic Wars to supply the British Royal Navy with pulley blocks. They started the age of mass-production using all-metal machine tools and are regarded as one of the seminal buildings of the British Industrial Revolution. They are also the site of the first stationary steam engines used by the Admiralty.〔Coad, Jonathan, The Portsmouth Block Mills : Bentham, Brunel and the start of the Royal Navy's Industrial Revolution, 2005,ISBN 1-873592-87-6〕 Since 2003 English Heritage has been undertaking a detailed survey of the buildings and the records relating to the machines. ==Development of Portsmouth Dockyard== 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. The dock system at Portsmouth has its origins in the work of Edmund Dummer in the 1690s. He constructed a series of basins and wet and dry docks. Alterations were made to these in the course of the eighteenth century. One of the basins had become redundant by 1770 and it was proposed to use this as a sump into which all the water from the other facilities could drain. The water was pumped out by a series of horse-operated chain pumps. 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. His office employed several specialists as his assistants—Mechanist (engineer), Draughtsmen, Architect, Chemist, Clerks, and others. The Inspector General's office was responsible for the introduction at Portsmouth of 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. They also introduced similar modernisation at the other Naval dockyards in conjunction with M I Brunel and Maudslay. 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. He installed a steam engine designed by a member of his staff, James Sadler, in 1798 which, as well as working the chain pumps, drove woodworking machinery and a pump to take water from a well round the dockyard for fire-fighting purposes. This well was some away and the pumps operated by a horizontal reciprocating wooden spear housed in a tunnel running from the engine house to the top of the well. The Sadler engine was a house-built table engine installed in a single-storey engine house with integral boiler; it replaced one of the horse-drives to the chain pumps. This engine was replaced in 1807 in the same house by another, more powerful, table engine made by Fenton, Murray and Wood of Leeds and, in turn, in 1830 by a Maudslay beam engine. In 1800 a Boulton and Watt beam engine was ordered as back-up and was housed in a three-storey engine house in line with the Sadler engine house. 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. This allowed the construction of two parallel ranges of three-storey wood mills, the southern to incorporate both engine houses and their chimney stacks, the chain pumps and some wood working machinery. The northern range was directly over the vaults and was to house more woodworking machinery. The buildings were designed by Samuel Bunce, the architect of Bentham's staff. While the vaults were under construction Bentham was ordering woodworking machinery of his own design, mostly up-and-down saws and circular saws. These were fitted-up in both ranges, the power to drive them being transmitted from the engines to the north range by underdrives through the upper layer of vaults, and then by vertical shafts to the upper floors of the buildings. The final drives to the machines was by flat belts running on pulleys. This machinery was planned to cut timber for the numerous smaller parts used in shipbuilding, especially joinery, which had previously been cut by hand, such as components for tables and benches, as well as small turned goods like belaying pins. There is evidence that he had developed a rotary wood-planing machine but details of this are obscure. There is also evidence that the complex housed a pipe boring machine, whereby straight elm trees were bored out for pump dales. These could be up to 40 ft long and were fitted through the decks of a vessel to pump seawater to the deck. There was a machine for making treenails—long wooden dowels used for fixing wooden parts of a ship together. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Portsmouth Block Mills」の詳細全文を読む スポンサード リンク
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