# Dictionary of National Biography, 1927 supplement/Arrol, William

​ARROL, Sir WILLIAM (1839–1913), engineering contractor, was born at Houston, Renfrewshire, 13 February 1839, the son of Thomas Arrol, who began life as a spinner and afterwards became manager at the works of Messrs. Coats, thread manufacturers, at Paisley. At the age of nine Arrol began work in the bobbin department of Messrs. Coats, but disliking factory work was apprenticed in 1853 to Thomas Reid, a blacksmith at Paisley; in 1863 he became foreman at the works of Laidlaw and Son, boiler and bridge manufacturers, at Glasgow. Five years later (1868) he was able to set up as a boiler-maker on his own account, and in 1872 began the construction of the Dalmarnock ironworks, near Glasgow, which in time covered 20 acres, employed 5,000 men, and became the largest structural steelworks in the United Kingdom. Among early contracts were two for the Caledonian Railway; one, a five-arched bridge at Bothwell, the other, a heavy viaduct carrying the main line over the Clyde into Glasgow.
Before 1870 direct railway communication between the north of Scotland and England was barred by the estuaries of the Tay and Forth. At that time plans were approved for a long girder bridge over the Tay and a suspension bridge over the Forth. The Tay bridge was built in 1870–1877, and a beginning made with that over the Forth, the contract for the latter being placed with the Dalmarnock firm. But on 28 December 1879, during an exceptionally heavy storm, the centre spans of the Tay bridge were blown down, together with a railway train which was crossing at the time. A new Tay bridge of eighty-five spans, designed by William Henry Barlow [q. v.], was constructed by Arrol's firm in 1882–1887; and a cantilever bridge of a new type was designed by (Sir) John Fowler [q. v.] and (Sir) Benjamin Baker [q. v.] for the Forth. In 1883 the firm of Tancred, Arrol, & Co. was formed to undertake the construction of the Forth bridge, and it was completed in 1890. On the site of the bridge the estuary narrows to about a mile across and is divided into channels, 200 feet in depth, by the island of Inchgarvie. The bridge consists of two main spans, each one-third of a mile (1,710 feet) in length, and side spans. Larger at that time than any rigid or stable bridge, and little exceeded by any similar structure since, the design of the Forth bridge was governed by the condition that the erection had to be effected without scaffolding, by building out from the piers. For its construction there were required 51,000 tons of steel, 65,000 cubic yards of concrete, 49,000 cubic yards of rubble, and 750,000 cubic feet of granite. The piers were sunk by excavation in compressed air. The total length of the bridge is 8,295 feet, the height above high-water level 150 feet, and the height of the towers 361 feet. Great as is the credit due to the engineer designers, much is due also to the constructors, without whose courage, resource, and mechanical skill, the bridge could not have been built in the time, and at the moderate cost of £3,000,000.
Arrol added a designing department to the Dalmarnock works, and constructed many other bridges, including the steel work for the Tower bridge, London (1886–1894), the Nile bridge at Cairo (1904–1908), and the Wear bridge at Sunderland (1905–1909). The first is interesting owing to the size of the bascules, which open for the passage of ships; they each weigh 1,200 tons, and are moved by hydraulic power.
Arrol, who was knighted in 1890, did not take a large part in public affairs. He was deputy lieutenant for the county of Glasgow, J.P. for the county of Ayr, and for fourteen years (1892–1906) he represented South Ayrshire in parliament ​as a liberal-unionist. In 1885 he bought the estate of Seafield, at Ayr, built a house there, took pleasure in gardens, and collected pictures. He died there 20 February 1913.
Arrol was married three times: first, in 1864 to Elizabeth Pattison (died 1904); secondly, in 1905 to Miss Hodgart (died 1910), of Lockerbank, Ayr; thirdly, in 1910 to Elsie, daughter of James Robertson, of London. He had no children.
[Philip Phillips, The Forth Bridge, 1889; Proceedings of the Institution of Mechanical Engineers, February, 1913; Transactions of the Institution of Engineers and Ship-builders in Scotland, vol. lvi, 472, 1912–1913; Engineering, 21 February 1913.]
W. C. U.