# Dictionary of National Biography, 1885-1900/Seaward, John

​SEAWARD, JOHN (1786–1858), civil engineer, son of a builder, was born at Lambeth, London, in January 1786, and began life as a surveyor and architect, working with his father. He was afterwards engaged by Grillier & Co., contractors for the erection of Vauxhall Bridge; the direction of that work was entrusted to Seaward, and this circumstance brought him the acquaintance of Jeremy Bentham and Ralph and James Walker. He next managed some lead-mines in Wales, acquired a knowledge of chemistry, and became friendly with Woolf, Trevithick, and other mechanical engineers. Returning to London, he superintended the construction of Gordon's, Dowson's, and other docks on the Thames, and became agent for the Gospel Oak Ironworks in Staffordshire. He was at the same time connected with the Imperial and Continental Gas Company, and introduced gas lighting into several towns in France, Belgium, and Holland. In 1823 he made drawings for a new London Bridge of three arches, each of 230 feet span. In 1824 he established the Canal Ironworks, Millwall, Poplar, for the construction of machinery, more particularly of marine engines. The first vessel built there in 1825, the Royal George, was intended to run between Dover and Calais. He joined the Institution of Civil Engineers as a member in 1826, and was a frequent attendant at the meetings.
A younger brother, Samuel Seaward (1800–1842), joined John about 1826; the brothers produced machinery for every part of the world, and made the name of Seaward widely known. In 1829 they assisted in the formation of the Diamond Steam Packet Company, and built the engines for the boats which ran between Gravesend and London. Of these, the Ruby and the Sapphire were types for speed and for accommodation. In 1836 the brothers brought out the direct-acting engines for the Gorgon and Cyclops, known as Seaward's engines, nearly dispensing with the heavy side-beam engines which up to that period were in general use. Their success was complete, and the saving obtained in the consumption of fuel by the double-slide valve, both for the steam and exhaust, with other improvements, caused the government to entrust the Seawards with the building of twenty-four steamboats and some smaller vessels. At the same time they adapted their engines to the vessels of the East India Company, the Steam Navigation Companies, and the ships of foreign governments. They early advocated the use of auxiliary steam power for the voyage to India, and experimented with the Vernon in 1839 and 1840 with great success (Trans. Instit. of Civil Engineers, 1842, iii. 385–401). They also designed large swing-bridges, dredging machines, cranes, and other dock-apparatus, besides machinery for lead, saw, and sugar mills. Among the improvements and inventions for which John Seaward was personally responsible were the tubular boilers, which are still used in the royal navy, the disconnecting cranks for paddle-wheel engines, the telescopic funnel, the self-acting nozzles for feed and for regulating the saturation of the ​water in marine boilers, the double passages in cylinders both for steam and eduction, the cheese-couplings used to connect and disconnect the screw propeller to and from the engines, and other minor improvements.
The death of Samuel Seaward, who was a F.R.S., at Endsleigh Street, London, on 11 May 1842 (Min. of Proc. of Instit. of Civil Engineers, 1842–3, ii. 11–12), threw upon John Seaward the entire management of the Canal Ironworks. In the construction of the engines of the Amazon, eight hundred horse power, he produced one of his most perfect works. The vessel unfortunately was destroyed by fire on her first passage to the West Indies on 4 Jan. 1852. He died at 20 Brecknock Crescent, London, on 26 March 1858.
He was the author of: 1. ‘Observations on the Rebuilding of London Bridge, with an examination of the Arch of Equilibrium proposed by Dr. Hutton, and an investigation of a new method for forming an arch of that description,’ 1824. 2. ‘Observations on the Advantages and Possibility of successfully employing Steam Power in navigating Ships between this country and the East Indies,’ 1829, signed J. S. & Co. For ‘The Steam Engine,’ by Thomas Tredgold, 1850, he contributed articles on ‘Steam Navigation,’ ‘Vessels of Iron and Wood,’ the ‘Steam Engine,’ and on ‘Screw Propulsion.’
G. C. B.