The Denny family was engaged in steamship construction from as early as 1814 when William Denny Snr ( 1779-1833 ) formed a partnership, located in Dumbarton, West Dunbartonshire, Scotland, with Archibald McLachlan. After his death, three of his six sons, William, Alexander and Peter ( 1821-1895 ), set up a partnership in 1844 , known as Denny Brothers , marine architects, to design iron steamers. William had been chief draughtsman in the Belfast, Northern Ireland, yard of Coats & Young before he was appointed yard manager at Robert Napier's Govan yard in 1842 . Alexander had been in business independently as a marine architect in Paisley, Renfrewshire, Scotland, and Peter had worked as a clerk before becoming assistant to, first, William in Govan, Glasgow, Scotland, and then Alexander in Paisley. .
Within a year of establishing their new company, the brothers moved back to Dumbarton and were in business as shipbuilders, taking up the lease of a small yard known as Kirk Yard situated on the banks of the River Leven. In 1845 , they leased the Wood Yard which had been their father's old premises and they fitted this out for the building of iron steamers. At this point, the firm employed 14 men and had a capital of £800. The business prospered, and in 1846 , another brother, James Denny, was taken on as a fourth partner
In 1849 , Alexander left the partnership and the name was changed to William Denny & Brothers . In 1850 , with his brother William's agreement, Peter Denny set up a separate marine engineering company in Dumbarton, to fit out the hulls that William Denny & Brothers were building and, up until that point, sending up the Clyde to Glasgow to be engined. His partners in this venture were John McAusland and a Greenock, Inverclyde, Scotland, engineer, John Tulloch. The new company was known as Tulloch & Denny. Within a very short time, however, William Denny died, leaving his younger brothers James and Peter in control of the firm. Peter Denny was the more active partner and he began to expand the company's horizons, investing in other shipping companies, building ships speculatively and operating some vessels. By 1859 , the total assets of the company, covering shipping, shipbuilding and engineering amounted to £136,634. In that year the firm acquired the North Yard on the River Leven and extended the engineering shops of Tulloch & Denny.
In 1862 , James Denny and John Tulloch both resigned. Peter Denny became sole partner of the shipyard, William Denny & Bros and a partner with John McAusland in the re-formed engineering company, Denny & Co. Through his connections in the Free Church of Scotland, Peter Denny came into contact with the partners of the shipping company, Paddy Henderson & Co. In addition to building ships for the company, Peter Denny joined with the partners in speculating in Confederate Bonds and also in building a Blockade Runner, a cargo transporter used by the Confederate navy to evade the Union blockade by trading with Britain and Europe via the West Indian or Caribbean islands during the American Civil War ( 1861-1865 ). The association with Henderson & Co continued and in 1864 , Peter Denny became a major investor, putting up 18 per cent of the capital, in the Albion Shipping Co, Henderson & Co's New Zealand shipping operation. In 1865 , the partners of Henderson & Co and the Denny companies established the Irrawaddy Flotilla & Burmese Steam Navigation Co.
Meantime Peter Denny continued to expand his shipbuilding operation in Dumbarton, and by 1867 , had transferred his whole operation to a new purpose built yard on the River Leven. In 1868 , Peter Denny took the eldest of his sons, William Denny III, into partnership and in 1871 , his nephew Walter Brock joined the company, becoming a partner in 1873 . Walter Brock was an engineer who, while at Dumbarton, developed the quadruple expansion engine and ways of installing it into older vessels. William Denny III was an experimental scientist and in 1870 , he persuaded his father to adopt progressive speed trials over the measured mile, ensuring a qualitatively more standardised product for customers. He also pioneered the construction of double cellular bottoms for cargo vessels and ensured that the company adopted mild steel in vessel construction. In addition he encouraged his father to build a large experimental tank for testing ship models. In 1881 Denny built a tank 300 ft 22 ft and 9 ft deep, the first such experimental tank in any commercial shipyard in the world.
In 1874 , Peter Denny became the chairman and managing director of the incorporated firm of the British & Burmese Steam Navigation Co, jointly owned by Henderson & Co and by Peter Denny, Walter Brock and John McAusland, the latter three partners taking 580 of the 2,299 shares of £50 each. This company, reformed in 1876 as the Irrawaddy Flotilla Co, built flat bottomed river craft for use in the Burma area. In 1882 , encouraged by their success in Burma, the partners set up another company, La Platense Flotilla, to build river craft in the Argentinian and Uruguayan river systems. William Denny III represented the Denny shareholding. The venture ended in financial loss and tragedy when revolution, drought and inflation left the combined Denny and Henderson interests with unpayable gold based obligations and debts entailed in attempts to buy out local competition. William Denny III took his own life and La Platense was wound up in 1890 . It is a tribute to the strength of the business as a whole that it was able to survive losses amounting to over £487,000.
Maurice Denny ( 1886-1955 ), son of Archibald Denny and grandson of Peter Denny, became a partner in William Denny & Brothers in 1911 . He had studied naval architecture at the Massachusetts Institute of Technology in Boston, USA, graduating with first class honours in 1909 . In 1918 , the two parts of the business, the Leven shipbuilding firm of William Denny & Brothers and the marine engine works of Denny & Co were amalgamated as a single limited company, William Denny & Brothers Ltd. In 1922 , Maurice Denny became chairman of the company, a post which he held for the next 30 years. After the first world war (1914-1918), conditions became generally more difficult. There were immediate shortages in steel production, and more long-term over-capacity in shipping leading to a worldwide depression of markets. Moreover there was a growth of competition especially in the far-eastern waters where the company had developed much of its earlier business. Nevertheless, the company strove to retain its high reputation for research and innovation, particularly in the areas of high-pressure turbines, for high-speed passenger vessels, hull forms and stabilising systems. The Denny-Brown stabilising system, developed by Maurice Denny in collaboration with William Wallace of Brown Bros, was first fitted extensively during the Second World War to give greater stability for gunnery, but post-war, it became a feature for passenger vessels.
Difficulties in the market, led Maurice Denny into a more politically active role in the industry. He and the firm were founder members of the Shipbuilding Conference established in 1928 to deal, initially, with unfair contract conditions imposed by shipowners. Maurice Denny became a leading official in the Shipbuilders' Employers Federation (Chairman from 1940 ) for which he received a Baronetcy in 1936 . Serving on the Advisory Committee on Merchant Shipbuilding to the Ministry of Shipping during the Second World War Sir Maurice worked with Sir Henry Lithgow to co-ordinate the shipbuilders' work and represent their interests. Sir Maurice perceived clearly that conditions would be very different once the war was ended and sought to prepare shipbuilders for that time, arguing especially that there was a need for shipbuilders and shipowners together to co-operate with government in planning the future development of the whole industry. His hopes were fulfilled, in a limited sense relating to technical innovation, in the setting up of the British Shipbuilders Research Association in 1944 , of which he was a member and later, chairman.
After the second world war, William Denny & Brothers Ltd maintained their place in the market by building fast cross channel passenger craft. But they were increasingly forced into the business of producing cargo vessels where they encountered strong competition from cargo lines like Ellerman and the Bowater Steamship Co and where it was increasingly difficult to rely on existing customer links. Sir Maurice retired from the position of chairman in 1952 . The company did not long survive and went into voluntary liquidation in 1962 . The liquidation was handled by McLellan Moores & Co, then of 112 West George Street, Glasgow. The experiment tank at Dumbarton was purchased in 1964 by Vickers Ltd and was subsequently acquired by the Scottish Maritime Museum.