[BITList] Life, span

Mon Oct 4 15:17:20 BST 2010

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Rennie,  John  (1761-1821), engineer, was born on 7 June 1761 at Phantassie, Haddingtonshire, the youngest of the nine children of James Rennie (d. 1766), a farmer and owner of a brewery, and his wife, Jean, nee Rennie (1720-1783). George Rennie  (1749-1828), the agriculturist, was his oldest brother and took over the family interests when their father died in 1766. Their eldest sister, Marion (1744-1809), married James Mylne (1738/9-1788), poet. John went to the parish school at Prestonkirk. A precocious interest in machinery was nurtured by the well-known millwright Andrew Meikle (1719-1811), inventor of the threshing machine and improver of the windmill, who lived on the estate. Rennie started to work for Meikle when he was twelve, getting a grounding in practical mechanics. For two years (1775-7) he was then at Dunbar high school, where a visitor, David Loch, singled him out for his 'amazing powers of genius' in mathematics and experimental and natural philosophy. Later, when his teacher at Dunbar retired, Rennie was asked to succeed him but agreed to do so only temporarily, as his ambitions lay elsewhere.

After working again for Meikle, with his help and consent Rennie set up on his own as a millwright in 1779. Among his first jobs was building a mill for his brother to house one of Meikle's earliest threshing machines. Though soon in a good way of business, he opted to combine practical work with studies at Edinburgh University, where he matriculated in November 1780, continuing until 1783. Here he made friends with two eminent teachers, the chemist Joseph Black and the professor of natural philosophy, John Robison, and gained a breadth of scientific interest as well as some grasp of theoretical engineering concepts.

In 1783 Rennie took a study tour into England, making notes on canals, bridges, and machinery along his route. His destination was Birmingham, where a letter from Robison procured him an introduction to James Watt. Watt, in need of a millwright to extend the mechanical scope of his steam engine, was greatly taken with Rennie. The next year Boulton and Watt offered him the job of looking after their London business and erecting the engines they supplied for the Albion Mills, the revolutionary flour mill at the south end of Blackfriars Bridge conceived and designed by Samuel Wyatt. To this end Rennie moved to London, setting up a workshop at a Thames wharf near the mill. The millwork for the twenty sets of grinding stones was supplied by Wyatt, but the substitution of much iron gearing for the customary timber was probably Rennie's idea; there was much friction between the two men.

Rennie opened the Albion Mills to visitors when production began in 1786, despite the secretive Watt's disapproval. The building burned down in 1791, but by then Rennie's reputation was made and he was supplying millwork for customers as far away as France, Spain, and Portugal. He made moving machinery for mills, breweries, and factories of all kinds, including a variety of machines for the new Boulton and Watt factory at Birmingham (erected by his foreman, Peter Ewart). Rolling mills for mints were a speciality, most of the equipment for the new Royal Mint at Tower Hill being Rennie's. He was ingenious in improving mechanical devices. A pioneer in applying steam power to pile-driving and dredging, he was among the first to make regular use of ball-bearings, improved the water-wheel and diving bell, experimented with stone pipes for water supply, and contributed to the evolution of the gantry crane. To meet the demand for his machines, he in 1810 built a larger factory at Holland Street, Southwark, on part of the old Albion Mills site.

The year 1790 proved to be significant for Rennie, both personally and professionally. He married Martha Ann Mackintosh (d. 1806). They had nine children, of whom George Rennie  (1791-1866) and Sir John Rennie  (1794-1874) carried on his work. A daughter, Anna, married the architect C. R. Cockerell. In 1790 a second phase of Rennie's career also began when he was appointed surveyor to the Kennet and Avon Canal. Design and consultancy for civil engineering henceforward took up the bulk of his time. Along the Kennet and Avon (1794-1813), 57 miles long and with seventy-eight locks, many bridges, and several aqueducts and tunnels, Rennie's penchant for solidity first made its mark. But he was hampered by a tight budget and problems of water supply, only in part alleviated by the steam-powered pumping station at Crofton and the one at Claverton powered by a water wheel. In the same years he laid out the Rochdale Canal and the Lancaster Canal with the noble Lune aqueduct, as well as the Aberdeen Canal, the Crinan Canal, the Royal Canal of Ireland, and the Royal Military Canal (a product of the Napoleonic invasion scare of 1803-4).

Rennie also took on a multitude of river navigation and harbour improvements, fen drainage schemes, and waterworks. In London, he was a key figure in the expansion of the commercial docks during the French wars. He acted as engineer to the London docks (1800-05) and with Ralph Walker to the East India docks (1803-6), and he built extensions and some remarkable sheds at the West India docks (1809-17). For the Admiralty, Rennie made wartime improvements to the Thames naval dockyards, including a superb steam-powered smithy at Woolwich, but his detailed scheme of 1807 for a wholly new dockyard at Northfleet was not carried out. His grandest executed work for government was the mile-long protective breakwater at Plymouth Sound, started in 1811 and completed in 1848. Its scale was admired by Napoleon when he arrived as a prisoner at Plymouth in 1815, to Rennie's gratification.

The thoroughness of his reports was a key to Rennie's reputation. He was often asked to adjudicate on others' projects, and his name was of great value to promoters. He worked well with others and could delegate, but was conscious of his own worth. His foremost collaborative endeavour was with Robert Stevenson, on the famous Bell Rock lighthouse off Arbroath (1807-10). The apportionment of responsibility for this work led to prolonged disputes between their respective descendants, but it is now certain that while Stevenson designed the lighthouse in the main, Rennie's role too was significant.

Rennie is now chiefly admired and remembered as a bridge-builder. He was designing bridges as early as 1784 and extended their range throughout his career. His masonry bridges were marked by solidity, precision, and a definite structural philosophy. He was alive and receptive to the ideas of French engineers of Perronet's school, but critical of their practical record. The multi-arched road bridges of his maturity all had swept walls to the abutments, elliptical or segmental arches, pointed breakwaters, hidden inverted arches over the piers, and a level surface from end to end.

Rennie's crowning achievement was the trio of metropolitan bridges spanning the Thames: Waterloo Bridge, Southwark Bridge, and London Bridge, all constructed by Edward Banks (1770-1835) of the early contracting firm, Jolliffe and Banks, which had built many of his canals. Waterloo Bridge (1811-17) was his masterpiece. Though privately promoted, it was the most prestigious bridge project Britain had yet seen. The design was based on his earlier bridge at Kelso. It had nine equal arches, facings in granite (then a new building material in London), and twin Doric columns against the piers. Canova is said to have remarked it was worth coming to England merely to see Waterloo Bridge, while a modern authority has described it as 'perhaps the finest large masonry bridge ever built in this or any other country'  (A. W. Skempton, Transactions of the Newcomen Society, 44, 1971-2, 36). The subsidence of one of the piers led to its destruction by the London county council in the 1930s, despite strenuous and prolonged public protest. Southwark Bridge (1814-19), another private undertaking, had a superstructure of three unequal iron arches on granite piers, the central arch being the widest cast-iron span ever built in Britain. These arches followed on from a previous iron bridge by Rennie (with Thomas Wilson) at Boston, Lincolnshire (1805-8). Though he was keen to vie with Telford in the design of iron bridges, and made an early sketch for crossing the Menai Strait with a single arch and flat deck (1801-2), he was less completely a master of this developing genre. The complexity and expense of the Southwark arches led to the bankruptcy of the iron subcontractors, Walkers of Rotherham, and Rennie was never fully paid for his work; a second large iron bridge, designed on similar principles, was sent out in sections to Lucknow, but not erected there for many years. London Bridge, designed in conjunction with his sons and built posthumously (1823-31), was the last of his masonry bridges. It was removed in 1968 and re-erected in abbreviated form at Lake Havasu City, Arizona, leaving London with no extant memorial to Rennie's genius.

Rennie was elected fellow of the Royal Society in 1798, but declined the knighthood offered to him by the prince regent when Waterloo Bridge was opened. Though strong, Rennie consistently overworked. His one recorded 'holiday', to France and the Low Countries in 1816 with James Watt junior, was largely taken up with visits to docks and harbours. He did however have a country retreat for family life at Frensham Vale, Farnham. Eventually he fell victim to his own energies, and died of liver disease on 4 October 1821 after a short illness at his home in Stamford Street, Southwark. He was buried in St Paul's Cathedral, where a plain granite slab in the crypt marks his grave. Among his many engineering pupils or assistants were, besides his sons, John Aird, Henry Bell, Anthony Bower, William Tierney Clark (also a fine bridge-builder), Peter Ewart, Francis Giles, James Hollinsworth, John Thomas, and Joseph Whidbey.

Rennie was a handsome, big man nearly 6 feet 4 inches tall, with equal determination and charm. In private he had a short temper, but he made and kept friends. Charles Dupin pronounced him 'friendly and welcoming to all foreign engineers who came to England to study his works and profit from his genius'  (Dupin, 6). By religion he was brought up and remained Presbyterian. Like every engineer of his day, he took risks and made mistakes. His stone pipes for the Grand Junction Water Company were an abject failure, and the bridge he built at Highgate Archway was to collapse. A common criticism levelled at Rennie was the massiveness and expense of his structures, but Rennie built to last, and for safety and dignity's sake was free with his clients' money. His capacity for combining manufacturing with design derived from his origins as a millwright or mechanical engineer, but it is as a constructor that he is chiefly now remembered. He and Telford were the greatest civil engineers of their day. Although many modern historians of engineering have preferred Telford on the grounds of his originality in structural design, other authorities have been equally impressed by Rennie. He enjoyed a wider range of skills, greater theoretical ability, and more social approbation than Telford, but has been less fortunate in the survival of his major structures. A memorial of 1928 stands on the hill above East Linton, near Phantassie; in London there is only a poor modern plaque under the north end of the present Waterloo Bridge, where foundations of Rennie's bridge still remain.

Andrew Saint 

Sources  C. T. G. Boucher, John Rennie (1963) + W. Reyburn, Bridge across the Atlantic (1972) + Colvin, Archs. + C. Dupin, Notice necrologique sur John Rennie (1821) + D. Brewster and others, eds., The Edinburgh encyclopaedia, 3rd edn, 18 vols. (1830) + S. Smiles, Lives of the engineers, 2 (1861) + J. Rennie, Autobiography of Sir John Rennie, FRS (1875) + T. Ruddock, Arched bridges and their builders (1979) + C. Fox, ed., London, world city, 1800-1840 (1992), 54-6, 311-14 + DNB + private information (2006) [H. Mound]
Archives Inst. CE, drawings, papers, and reports + NL Scot., accounts, corresp., and notebooks + NL Scot., letters + TNA: PRO, letters, RAIL 1008/87 + U. Edin. L., corresp. | Bath and North East Somerset RO, Bath, report on Kennet and Avon canal + Beds. & Luton ARS, letters to Samuel Whitbread + Birm. CA, letters to Boulton and Watt + Birm. CA, corresp. with Boulton family + Birm. CA, letters to James Watt + BL, letter and reports to Viscounts Melville, Add. MS 41345 + BL, report on Northfleet New Arsenal, Add. MS 27884 + British Waterways Archive, MS plans + Cambs. AS, reports on fen drainage + Dorset RO, report and corresp. relating to Tamar navigation canal + Lincs. Arch., corresp. and papers relating to Boston Bridge + Lincs. Arch., reports and papers relating to Lincolnshire River Authority + LUL, specification for rebuilding London Bridge + Mitchell L., Glas., Glasgow City Archives, corresp. and papers relating to Clyde Harbour + NL Scot., papers relating to Whiteadder Bridge + Rochester Bridge Trust, corresp. and reports on Rochester Bridge + Southampton Archives Office, reports on Southampton docks + Staffs. RO, report on Leek canal + U. Birm. L., MS opinion on Shardlow and Nottingham canal + U. Edin. L., letters to Thomas Townshend + Warks. CRO, letters to Sir Roger Newdigate
Likenesses  M. A. Shee, oils, c.1794, Scot. NPG · H. Raeburn, oils, c.1800, Scot. NPG [see illus.] · G. Dance, drawing, 1803, NPG · F. Chantrey, marble bust, 1818, NPG; plater cast, AM Oxf. · W. Holl, stipple, pubd 1861 (after A. Skirving), NPG · W. Bain, bronze medallion, NPG · T. O. Barlow, mixed engraving, NPG · F. Chantrey, pencil drawing, NPG · G. P. Harding, pencil drawing (after F. L. Chantrey), NPG · H. Raeburn, portrait · E. Scriven, stipple and line engraving (after S. Kirven), NPG · E. Scriven, stipple and line engraving (after A. Skirving), NPG · F. J. Skill, J. Gilbert, and E. Walker, group portrait, pencil and wash drawing (Men of science living in 1807-8), NPG · J. Thomson, stipple (after W. Behnes), BM, NPG; repro. in European Magazine (1821)