- Engineering & Materials
- Ferranti, Sebastian Ziani de (1864–1930)
Ferranti, Sebastian Ziani de (1864–1930)
English electrical engineer who pioneered the high-voltage A.C. electricity generating and distribution system still used by most power networks. He also designed, constructed, and experimented with many other electrical and mechanical devices, including high-tension cables, circuit breakers, transformers, turbines, and spinning machines.
Ferranti was born in Liverpool on April 9, 1864. From his youth he was fascinated by machines and the principles by which they operate. After moving south he attended St. Augustine's College in Ramsgate, Kent, and so impressed his teachers with his mechanical ideas that they set aside a room in which he could experiment. During this time he constructed an electrical generator. He left school in 1881 and took a job at the Siemens works in Charlton near London. He discovered that he could rotate and therefore mix the molten steel in a Siemens furnace by applying an electric current, and within a year he was supervising the installation of electric lighting systems for the company. A year after that—still only 18 years old—he was engineer to his own company, which designed and manufactured the Thompson–Ferranti alternator and installed lighting systems. The company was formed in partnership with Lord Kelvin (Joseph Thompson) and a solicitor named Ince.
In 1886 Ferranti became engineer to the Grosvenor Gallery Company in London. The gallery had its own electricity generating system for lighting, and was also selling electricity to outside customers. Ferranti modified the system considerably to meet extra demand and, realizing the business potential, led the Grosvenor Company into the formation of a separate enterprise, the London Electric Supply Corporation Ltd., and suggested building a large generating station at Deptford. Extending an electricity supply to such a large area would, he argued, eventually become more economical and practicable than hundreds of small electrical enterprises serving limited areas. Most of the small systems used direct current of 200–400 volts together with storage batteries (accumulators), and were suitable only over short distances and when the demand for electricity fell within suitable limits. To achieve large-scale distribution, Ferranti proposed using alternating current (A.C.) at 10,000 volts, which was fed by mains to London, where step-down transformers reduced it to a voltage suitable for its purpose. The idea was revolutionary, because electricity at more than 2,000 volts was considered to be extremely dangerous. The cable for the mains was made to Ferranti's design, and produced in 6 m/20 ft lengths that were spliced together without the use of solder. The Deptford power house and its associated distribution network became the basic model for the future of electricity generation and supply.
In 1888 Ferranti married Gertrude Ince, the daughter of his solicitor partner. Three years later he left the London Electric Supply Corporation and concentrated on work as a consultant and on the development of his own company. This firm went on to design and build all kinds of electrical equipment, most of which was designed by Ferranti himself. He was also involved with heat engines of various kinds, turbines, cotton-spinning machines, and, during World War I, the design and manufacture of steel casings.
He became president of the Institution of Electrical Engineers in 1911 and a year later was awarded a DSc degree by the University of Manchester. In 1929 he was elected a fellow of the Royal Society. He enjoyed motoring and was very proud of his fast journey times. He died after an illness while on holiday in Zürich, Switzerland, on January 13, 1930.
From the Hutchinson Dictionary of Scientific Biography, © RM, 2020. All rights reserved. Published under license in AccessScience, © McGraw-Hill Education, 2000–2020. Helicon Publishing is a division of RM.