Sommeiller
Sommeiller, Germain
ACHIEVEMENTS:
Invented first pneumatic drill
NICKNAME/ALIAS:
None
DATE AND PLACE OF BIRTH:
15 March 1815, Saint-Jeoire, France
DATE AND PLACE OF DEATH AND AGE AT DEATH:
11 July 1871, Saint-Jeoire, France. Aged 56
DISCIPLINE:
Engineer
FIELD:
Engineering
LANGUAGE:
French
PARENTS:
?
SIBLINGS:
?
SPOUSE:
?
CHILDREN:
?
EDUCATION:
University of Turin
MAJOR WORK:
None
LIFE AND TIMES:
Sommeiller was still a pupil at Turin when with two colleagues he applied for a patent for the utilisation of major falls of water to obtain compressed air. The three men had been named engineers for part of the railway line between Genoa and Turin.
In order to propel locomotives along steep inclines, they constructed a machine in which compressed air was introduced into a cylinder attached to a tube propeller which acted as a ram.
The machine worked so well that Sommeiller decided to adapt it for rock drilling. He obtained permission from the Piedmontese parliament to run trials with a view to excavating a tunnel through the Alps which would link the provinces of Piedmont and Savoy (which were then united under the crown of Sardinia but were separated geographically by the Alps).
Experiments were carried out in April and May 1857 at Coscia near San Pietro d’Arena with a drill driven by a reciprocating piston powered by compressed air. This was the first pneumatic drill* which over the next ten years Sommeiller developed and perfected.
The experiments at Coscia showed that the compressed air remained at a safe temperature due to the cylinder into which it was transmitted being constantly bathed in the compressing water. The loss of pressure deep into tunnel was found to be negligible and Sommeiller was also able to supply ventilation in the tunnel.
In August 1857 the king of Sardinia presided over a ceremony to mark the initiation of the project to excavate a tunnel through Mount Cenis. The work began by hand while Sommeiller worked on his machines.The waters of the river Arc in the north and the river Melezet in the south were utilised in order to raise the necessary volume of water.
The regulation of the water caused various setbacks, including flooding of the work site. In January 1861 Sommeiller’s drilling machines were introduced into the mountainside at Bardonecchia. Two years later they were introduced at the other end of the tunnel near Modane in the north.
During 1861/2, work progressed more slowly than it had when the drilling was done by hand but gradually became more rapid, although in July 1866 they met a bank of quartz which caused them great difficulties.
On December 26 1870 they completed the tunnel which was seven miles (12 kilometres) long.
ASSESSMENT: Sommeiller’s invention of the pneumatic drill made practicable the excavation of hard rock deep inside a mountain.
EXTRA CONNECTIONS: None
ONELINER: Germain Sommeiller, inventor of the pneumatic drill
BIBLIOGRAPHY:
Skeet, Charles J., The Mount Cenis Tunnel, Its Construction and Probable Consequences, London, 1873
Alphandery, M.F.,Dictionnaire des inventeurs francais, Paris, 1963