If asked to state who invented the pneumatic vehicle tyre, most people would answer that the honour belongs to the Scottish veterinary surgeon John Dunlop, whose invention in 1888 of a reliable rubber tyre for bicycles was certainly a very significant step on the way to the modern tyre.
However, the concept of pumping air inside a tube surrounding a wheel, with a view to absorbing most of the bumps and producing a smoother ride, goes back to 1845 and the Scottish civil engineer Robert William Thomson (1822-73).
Thomson had his own workshop from the age of 17 and later became a civil engineer on the burgeoning railway system. One of his most useful inventions in this capacity was a method for firing explosive charges remotely by using electricity, which no doubt saved many lives as tunnels and cuttings were blasted out of solid rock.
He was only 23 when he thought up the idea of the pneumatic tyre, which he termed the “aerial wheel”. It consisted of an air-filled tube of natural rubber encased in leather which in turn was fixed to the wheel of a carriage. He patented his invention in France in 1846 and the United States in 1847, and it proved to be a reasonable success. However, the leather coverings did not prove to be very durable, and Thomson did not proceed with further developments.
Instead, Thomson turned his attention to the possibilities offered by a new form of rubber, namely vulcanized rubber, that was tougher and more resilient to changes in temperature. The process had been invented in 1839 by Charles Goodyear, and it involved heat-treating rubber to which sulphur had been added. However, Thomson abandoned the concept of air-filled tubes and concentrated on developing carriage wheels shod with solid rubber tyres.
It was therefore left to John Dunlop to combine the use of air-filled tubes and vulcanized rubber covers to produce the sort of tyre that is familiar to us today. Dunlop’s work was extremely timely, given the important improvements in bicycle design in the 1870s and 1880s. The combination of the “safety” bicycle and Dunlop’s tyres led to a massive boost in popularity of the bicycle, which was to become a “must have” for people across the social classes.
However, Robert Thomson had the last laugh, because Dunlop was told in 1890 that Thomson’s earlier patents invalidated his own of 1888.© John Welford