The Contribution of Leonardo Torres Quevedo to Lighter-Than-Air Science and Technology

Abstract On 5 May 1902, Leonardo Torres Quevedo applied for a patent in France for 'Improvements in dirigible aerostats'. He had conceived a complex triangular inner structure for airships: a longitudinal frame made up of non-rigid ropes, permeable curtains and metal cables, joined to a metal articulated plane keel and two metal longerons, which rigidify altogether through the excess of pressure level of the gas. The initial system evolved to the design of an auto-rigid airship with a trefoil shape based upon a triangular non-rigid inner structure. After trials with two small models in Spain and France between 1906 and 1909, more than thirty units were manufactured in France between 1911 and 1936, and more than sixty in the UK between 1915 and 1919. But the number of different possible systems for the construction of dirigible balloons included in Torresquevedian contribution would cover more than one hundred years in airship designs.