St. Clair Tunnel
The St. Clair Tunnel is the name for two separate rail tunnels which were built under the St. Clair River between Sarnia, Ontario and Port Huron, Michigan. The original, opened in 1891 and used until it was replaced by a new larger tunnel in 1995, was the first full-size subaqueous tunnel built in North America.[3] (By full-size it is meant that it allowed a railroad to run through it.) It is a National Historic Landmark of the United States, and has been designated a civil engineering landmark by both US and Canadian engineering bodies.
The St. Clair Tunnel is the name for two separate rail tunnels which were built under the St. Clair River between Sarnia, Ontario and Port Huron, Michigan. The original, opened in 1891 and used until it was replaced by a new larger tunnel in 1995, was the first full-size subaqueous tunnel built in North America.[3] (By full-size it is meant that it allowed a railroad to run through it.) It is a National Historic Landmark of the United States, and has been designated a civil engineering landmark by both US and Canadian engineering bodies.
Contents
First tunnel (1891-1995)[edit]
The first underwater rail tunnel in North America[4] was opened by the St. Clair Tunnel Company in 1891. The company was a subsidiary of the Grand Trunk Railway (GTR), which used the new route to connect with its subsidiary Chicago and Grand Trunk Railway, predecessor to the Grand Trunk Western Railroad (GTW). Before the tunnel's construction, Grand Trunk was forced to use time-consuming rail ferries to transfer cargo.
The tunnel was an engineering marvel in its day and designed by Joseph Hobson.[5] The development of original techniques were achieved for excavating in a compressed air environment. The Beach tunnelling shield, designed by Alfred Ely Beach, was used to assist workmen in removing material from the route of the tunnel and left a continuous iron tube nearly 7,000 feet (2,100 m) long.[6]Freight trains used the tunnel initially with the first passenger trains using it in 1892.
The tunnel measured 6,025 feet (1,836 m) from portal to portal. The actual width of the St. Clair River at this crossing is only 2,290 feet (698 m). The tube had a diameter of 19 feet 10 inches (6.05 m) and hosted a single standard gauge track. It was built at a cost of $2.7 million.
The first underwater rail tunnel in North America[4] was opened by the St. Clair Tunnel Company in 1891. The company was a subsidiary of the Grand Trunk Railway (GTR), which used the new route to connect with its subsidiary Chicago and Grand Trunk Railway, predecessor to the Grand Trunk Western Railroad (GTW). Before the tunnel's construction, Grand Trunk was forced to use time-consuming rail ferries to transfer cargo.
The tunnel was an engineering marvel in its day and designed by Joseph Hobson.[5] The development of original techniques were achieved for excavating in a compressed air environment. The Beach tunnelling shield, designed by Alfred Ely Beach, was used to assist workmen in removing material from the route of the tunnel and left a continuous iron tube nearly 7,000 feet (2,100 m) long.[6]Freight trains used the tunnel initially with the first passenger trains using it in 1892.
The tunnel measured 6,025 feet (1,836 m) from portal to portal. The actual width of the St. Clair River at this crossing is only 2,290 feet (698 m). The tube had a diameter of 19 feet 10 inches (6.05 m) and hosted a single standard gauge track. It was built at a cost of $2.7 million.
Locomotives[edit]
Steam locomotives were used in the early years to pull trains through the tunnel, however concerns about the potential dangers of suffocation should a train stall in the tunnel led to the installation of catenary wires for electric-powered locomotives by 1907. The first use of electric locomotives through the tunnel in regular service occurred on May 17, 1908.[7] The locomotives were built by Baldwin-Westinghouse.[8]
In 1923, the GTR was nationalized by Canada's federal government, which then merged the bankrupt railway into the recently formed Canadian National Railway. CN also assumed control of Grand Trunk Western as a subsidiary and the tunnel company and continued operations much as before.
The electric-powered locomotives were retired in 1958 and scrapped in 1959 after CN retired and scrapped its last steam-powered locomotives on trains passing through the tunnel. New diesel-powered locomotives did not cause the same problems with air quality in this relatively short tunnel.
Steam locomotives were used in the early years to pull trains through the tunnel, however concerns about the potential dangers of suffocation should a train stall in the tunnel led to the installation of catenary wires for electric-powered locomotives by 1907. The first use of electric locomotives through the tunnel in regular service occurred on May 17, 1908.[7] The locomotives were built by Baldwin-Westinghouse.[8]
In 1923, the GTR was nationalized by Canada's federal government, which then merged the bankrupt railway into the recently formed Canadian National Railway. CN also assumed control of Grand Trunk Western as a subsidiary and the tunnel company and continued operations much as before.
The electric-powered locomotives were retired in 1958 and scrapped in 1959 after CN retired and scrapped its last steam-powered locomotives on trains passing through the tunnel. New diesel-powered locomotives did not cause the same problems with air quality in this relatively short tunnel.
Freight cars[edit]
After the Second World War, railways in North America started to see the dimensions of freight cars increase. Canadian National (identified as CN after 1960) was forced to rely upon rail ferries to carry freight cars, such as hicube boxcars, automobile carriers, certain intermodal cars and chemical tankers, which exceeded the limits of the tunnel's dimensions.
After the Second World War, railways in North America started to see the dimensions of freight cars increase. Canadian National (identified as CN after 1960) was forced to rely upon rail ferries to carry freight cars, such as hicube boxcars, automobile carriers, certain intermodal cars and chemical tankers, which exceeded the limits of the tunnel's dimensions.
Recognition[edit]
The tunnel was designated a Civil Engineering Landmark by both the Canadian and the American Societies of Civil Engineers in 1991.[3]
The tunnel was declared a U.S. National Historic Landmark in 1993.[2][3]
The construction of the tunnel has also been recognized as National Historic Event by Parks Canada since 1992, with a plaque at the site. [9]
St. Clair Tunnel 
View of the original tunnel (closed in 1994) from a 1907 postcardOverview Official name Paul M. Tellier Tunnel (second tunnel) Location St. Clair River between Port Huron, Michigan and Sarnia, Ontario Coordinates 42°57′30″N 82°24′38″WCoordinates: 42°57′30″N 82°24′38″W Operation Opened 1891 (first tunnel)
1994 (second tunnel) Closed 1994 (first tunnel) Operator Canadian National Railway Technical Length 6,025 feet (1,836 m) (first tunnel)
6,129 feet (1,868 m) (second tunnel) No. of tracks Single (each tunnel) 
Location on a map of MichiganDesignated October 15, 1970[1] Reference no. 70000684 Designated April 19, 1993[2] Built 1889 Architect Beach, Alfred; Hobson, Joseph Governing body Private
The tunnel was designated a Civil Engineering Landmark by both the Canadian and the American Societies of Civil Engineers in 1991.[3]
The tunnel was declared a U.S. National Historic Landmark in 1993.[2][3]
The construction of the tunnel has also been recognized as National Historic Event by Parks Canada since 1992, with a plaque at the site. [9]
 View of the original tunnel (closed in 1994) from a 1907 postcard | |
| Overview | |
|---|---|
| Official name | Paul M. Tellier Tunnel (second tunnel) |
| Location | St. Clair River between Port Huron, Michigan and Sarnia, Ontario |
| Coordinates | 42°57′30″N 82°24′38″WCoordinates: 42°57′30″N 82°24′38″W |
| Operation | |
| Opened | 1891 (first tunnel) 1994 (second tunnel) |
| Closed | 1994 (first tunnel) |
| Operator | Canadian National Railway |
| Technical | |
| Length | 6,025 feet (1,836 m) (first tunnel) 6,129 feet (1,868 m) (second tunnel) |
| No. of tracks | Single (each tunnel) |
 | |
| Designated | October 15, 1970[1] |
| Reference no. | 70000684 |
| Designated | April 19, 1993[2] |
| Built | 1889 |
| Architect | Beach, Alfred; Hobson, Joseph |
| Governing body | Private |
