Building of the St. Clair Tunnel National Historic Event

Sarnia, Ontario
Building of the St. Clair Tunnel © None
Building of the St. Clair Tunnel
© None
vBuilding of the St. Clair Tunnel © NoneBuilding of the St. Clair Tunnel © None
Address : Sarnia, Ontario

Recognition Statute: Historic Sites and Monuments Act (R.S.C., 1985, c. H-4)
Designation Date: 1992-01-01

Other Name(s):
  • Building of the St. Clair Tunnel  (Designation Name)

Importance: First underwater tunnel in North America, 1889-91

Plaque(s)


Existing plaque:  Sarnia, Ontario

THE ST. CLAIR TUNNEL This was the first subaqueous tunnel in North America and one of the great feats of the 19th century. Built in 1889-1891 to link the Canadian mainline of the Grand Trunk Railway with Chicago, the tunnel is 1,837 metres long with a 6-metre bore. Joseph Hobson, a Canadian engineer, designed and supervised its construction. His innovative combination of cutting shield excavation, cast iron tunnel lining, and compressed air broke the transportation bottleneck caused here and elsewhere by the impossibility of tunnelling through soft riverbeds