Engineers that Changed the World - Andre Citroen - Part I
written by: johnsinit•edited by: Lamar Stonecypher•updated: 2/28/2009
André Citroën, founder of the Citroën automobile company, was a brilliant and enigmatic man. Fascinated with double helical gears, he nonetheless was unenthusiastic about cars or driving. Educated in engineering, Citroën was also a compulsive gambler. Read more about this magnificent engineer.
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Childhood and education
The child of a Dutch Jewish diamond merchant, André Citroën was born February 5, 1878. Though his home life was comfortable, his father committed suicide when André was six, casting a shadow over the rest of André’s childhood. But André was smart, graduating from the Lycee Louise le Grand in 1894 with stellar grades. At 22, he earned his Diploma in Engineering from the École Polytechnique, though his academic standing there was only middling. After four years in the French army, Citroën, visiting Poland, saw something in a backwoods workshop that would change his life: a pile of wooden gearwheels.
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Helical and double helical gears
Helical gears, rather than the leading edges of the gear teeth running parallel to the axis of rotation, they run at a fixed angle. Thus, those gears look like a segment of a helix, or spiral. The angled gear teeth engage gradually, making helical gears run much smoother than traditional gears.
Citroën developed a double helical gear, resembling two single helical gears, threaded at opposite angles, stacked on a single axle. This allows for smoothness of helical gears, but adds the ability to take more torque than a traditional gear. Citroën returned to Paris and secured the patent for the double helical, or “herringbone" gear. Two herringbone “V"s, representative of the teeth of a double helical gear, still comprise the emblem of Citroën cars, and is recognized worldwide.
Citroën’s first factory, begun in 1904, mass produced double helical gears.
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World War I Munitions
In 1913 , when Citroën returned to the army as a captain in the reserves, he was assigned to a regiment equipped with the French 75 mm field gun. In the trenches in 1914, Citroën’s unit was unable to reply to an enemy artillery barrage, because they were short on shells. Having run his gear factory, Citroën was an expert on mass production of small, precision objects.
He wrote a report detailing how to employ mass production techniques to make 75 mm shells, and the army’s Chief of Artillery enthusiastically sent Citroën on his way.
But after the war, the demand for shells dried up, and Citroën’s passion for gears evolved into an idea to mass produce cars, like Henry Ford was doing. Two men have actiually met in 1920-s, understanding they were very much alike in their passion for cars. Soon after this encounter, Citroen established his automobile company - read about it more in Part II of this great person biography!