Engineer and pioneer of ship-building on the River Clyde. Born in Dumbarton, Napier worked as an apprentice to his father before moving to Edinburgh where he worked for engineer Robert Stevenson (1772 - 1850).
In 1815, he began his own engineering business in Glasgow. Acknowledging Henry Bell's work in the development of the steam-powered Comet, Napier began building marine steam engines. His first engine performed well in the steamer Leven and is preserved today at the Denny Ship Model Experiment Tank. He founded Parkhead Forge in Glasgow in 1837 to make iron for boiler plate. In 1841, he began building ships, which included some of the earliest iron-clad warships. Napier did much to establish the international reputation of the River Clyde as an centre for ship-building. With the Canadian shipping tycoon Samuel Cunard, he planned steam-powered vessels for transatlantic service and helped set up a company to run them. Napier also proved the economy and versatility of steam-powered vessels to the Admiralty.
In 1849 he built Leviathan, the world's first train ferry, which sailed from Granton to Burntisland. The Persia, launched in 1854, was the world's largest ship and the ironclad Black Prince, which was launched from the navy at Govan in 1861, was the largest Clyde-built ship of its time.
In 1861, the Parkhead Works were bought by Napier's son-in-law and William Beardmore (1825-77). Napier won international respect; he became President of the Institution of Mechanical Engineers (1863) and was honoured by France and Denmark. He made his home at West Shandon, by the Gare Loch, which he filled with a remarkable collection of furniture, porcelain and paintings, including old masters and works by 19th C. artists such as Raeburn and McCulloch.
Napier's wife died in 1875 and, overtaken by grief, he took ill and died at West Shandon the following year. Thousands lined the route to Dumbarton Parish Church, where he was buried in the family vault.