Robert Mylne (architect) - Blackfriars Bridge

Blackfriars Bridge

Mylne intended to establish himself as an architect in London, and to begin preparing his notes and sketches of Sicily for publication. However, on his arrival, he heard of the proposal to build a third bridge over the River Thames at Blackfriars. The closing date for the design competition was set for 4 October, giving Mylne less than three months to complete his scheme, although in his favour, he apparently found a friend in John Paterson, secretary of the Bridge Committee, and a fellow Scot. 69 schemes were entered into the competition, which was soon reduced to a shortlist of 14, including designs by the established engineers John Smeaton and John Gwynn, and the architects Sir William Chambers and George Dance the Elder. Mylne's design stood out, however, as it was the only one to propose flatter, elliptical arches, rather than round ones. This departure, as yet untried in Britain, provoked a public debate, and brought Mylne under attack from Dr Samuel Johnson, a friend of John Gwynn, who suggested that elliptical arches would be too weak. In response Mylne published a pamphlet, under the name "Publicus", in which the pseudonymous author praises Mylne's design, while criticising those of his competitors.

On 22 February 1760, Mylne was finally declared the winner of the competition, and he was appointed surveyor to the new Blackfriars Bridge, with overall responsibility for design, construction and future maintenance of the structure, on a salary of £400 a year. The foundation stone was laid on 31 October, and on 1 October 1764 the first arch, the 100-foot (30 m) wide centre arch, was completed. Mylne corresponded with Piranesi regarding the project, and the latter made an engraving, based on Mylne's reports, of the bridge under construction. Mylne introduced several technical innovations, including the use of removable wedges in the centring which supported the arches during construction, making it easier to dismantle. The foundations of the piers were on timber piles, levelled with an underwater saw, and the stonework was then built inside a huge caisson, a floating, submersible workspace, 86 feet (26 m) by 33 feet (10 m), and 27 feet (8.2 m) high.

The bridge was opened to all traffic in November 1769. As surveyor, Mylne was also responsible for laying out the approach roads; Bridge Street (now New Bridge Street) from the north, and Surrey Street (now Blackfriars Road) from the south. The squares of Chatham Square and Albion Place were laid out at the north and south ends of the bridge, respectively, and Mylne also designed the obelisk, which still stands, at St George's Circus, in 1771. Although Mylne was briefly the target of satirical anti-Scots cartoons and pamphlets at the time of winning the competition, the completed bridge was universally well-received, and tolls repaid the £152,840 cost of building within a few years. Mylne received his final payment for the works, of £4,209, in 1776, and held the post of surveyor until his death, but the bridge had to be replaced in 1869, after the rebuilding of London Bridge in 1831 affected the flow of the river.