Germain Sommeiller

Germain Sommeiller (1815 to 1871) was a civil engineer from Savoy, born at Saint-Jeoire and described by his source as Italian, who directed the building of the Fréjus Rail Tunnel, better known as the Mont Cenis Tunnel, between France and Italy. The 13.7 kilometre bore was the first of the great Alpine railway tunnels of the later nineteenth century that tied northern and southern Europe together. Sommeiller is remembered for putting pneumatic rock drilling and dynamite to work on the heading, which allowed record excavation speeds, and the tunnel was finished on 26 December 1870, eleven years ahead of the original schedule. It stayed the longest tunnel in the world until the Gotthard Rail Tunnel opened in 1882. Credit for the compressed air drill itself is contested: Grace's Guide notes that one source names Giovanni Battista Piatti as an earlier inventor and another says it grew from an idea of Thomas Bartlett, so Sommeiller is best read as the engineer who made the technology work at scale on this tunnel.