John Isaac Thornycroft

John Isaac Thornycroft
This photo of John Thornycroft appeared in Cassier's Magazine in 1896
Born	1 February 1843 Via Sistina, Rome, Papal States
Died	28 June 1928(1928-06-28) (aged 85) Bembridge, Isle of Wight, England
Nationality	English
Spouse(s)	Blanche Coules
Parent(s)	Mary Francis and Thomas Thornycroft
Engineering career
Discipline	Civil, Mechanical, Naval architect
Institutions	Institution of Naval Architects (Honorary Vice-President), Royal Society (Fellow, 1893), Institution of Civil Engineers (Council Member 1899-1907), Institution of Mechanical Engineers (Honorary Life Member), University of Glasgow (LL.D., 1901).
Projects	High speed vessels, steam- and combustion engine vehicles.
Significant design	Hull designs, boiler designs

Sir John Isaac Thornycroft (1843–1928) was a British shipbuilder, the founder of the Thornycroft shipbuilding company and member of the Thornycroft family.

He was born in 1843 to Mary Francis and Thomas Thornycroft. He attended the Regent Street Polytechnic and then the Royal School of Naval Architecture and Marine Engineering at South Kensington and at the same time, he began building a steam launch, the Nautilus in his father's study. The Nautilus was a fast boat with a reliable engine (also built by Thornycroft), and in 1862 it proved to be the first steam launch with enough speed to follow the contenders in the University race. The ensuing publicity prompted his father to purchase a strip of land along the Thames, adjacent to Chesterman's yard at Chiswick in 1864, and that became the start of John Thornycroft's shipbuilding career.

In 1866 Thornycroft took over Chesterman's yard completely, and John I. Thornycroft & Company was formally established, but at the beginning, John Thornycroft did not work there full time. Instead he worked for a while at Palmers Shipbuilding and Iron Company in Jarrow-on-Tyne before studying for a diploma in engineering at the University of Glasgow. At Glasgow he studied under Lord Kelvin and Professor Macquorn Rankine. On his return from Scotland he built the fast steam yacht Miranda in 1871, and thereby proved that small vessels could obtain speeds that were not thought possible at the time.