There was shipbuilding along the River Leven probably as early as the 15th century. Denny’s, the most famous Dumbarton yard,was sited just below the Rock at the mouth of the Leven. Over 1500 ships were built there between 1844 and its closure in 1963. This innovative company built the world’s first turbine steamer in 1901. Denny’s was the first commercial yard to use a Ship Model Experiment Tank (now part of the Scottish Maritime Museum) to refine the design of its hulls.
Members of the Denny family had been involved in shipbuilding in Dumbarton from the early 19th century. John Denny had built the first steamship to cross the Channel – the Margery – in 1814. However, it was William Denny & Sons who operated the most important yard on the Leven from 1844 to 1963. Always innovators they were responsible for a number of firsts: in 1878 the Rotomahana was the first all steel merchant ship; 1901 the King Edward was the world’s first commercial turbine steamer; in 1934 the Robert the Bruce, a car ferry on the Firth of Forth, was the first all welded vessel as well as the first diesel-electric paddle. Their ship model experiment tank, (1883) was instrumental in enabling Dennys’ to establish a reputation as specialist builders of fast cross-Channel steamers. In their final days they were experimenting with hovercraft.
Until very recently, one Denny’s vessel, The Second Snark, launched in 1938, used by them both as a tender and as a vessel for private entertaining, cruised out of Greenock. It has now been retired but is listed on the UK National Register of Historic Vessels.
Denny's were not the only ships famed for their speed. The tea clipper Cutty Sark, now under restoration in Greenwich,was also built in Dumbarton.