The Townline Tunnel is an underwater tunnel in

Welland Welland is a city in the Regional Municipality of Niagara in Southern Ontario, Canada. As of 2021, it had a population of 55,750. The city is in the centre of Niagara and located within a half-hour driving distance to Niagara Falls, Niagara-on ...

Ontario Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

carrying Highway 58A as well as the Canadian Pacific Railway under the

Welland Canal The Welland Canal is a ship canal in Ontario, Canada, connecting Lake Ontario and Lake Erie. It forms a key section of the St. Lawrence Seaway and Great Lakes Waterway. Traversing the Niagara Peninsula from Port Weller in St. Catharines ...

The tunnel

The Townline Tunnel is a two-cell reinforced concrete tunnel with a rectangular cross-section. The roof is a post-tensioned concrete slab. The tunnel was built as a part of the

Welland By-Pass The Welland By-pass, completed in 1973, was a massive construction project on the Welland Canal in Ontario, Canada. A new channel long was constructed, providing a shorter, more direct alignment between Port Robinson and Port Colborne and by-pa ...

project. Its construction was relatively easy since, like the

Main Street Tunnel The Main Street Tunnel, located in Welland, Ontario, Canada, is an underwater tunnel, carrying Niagara Road 27 and the unsigned designation of Highway 7146 under the Welland Canal. It is named as a part of East Main Street. The structure was bu ...

, it was being built at the same time as the channel above it and a simple

cut and cover A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A pipeline is not a tunnel, though some recent tunnels have used immersed tube cons ...

method could be used. The tunnel provides a sidewalk for pedestrians, two lanes for vehicular traffic, as well as room for three sets of tracks for rail vehicles. It was opened for automobiles on July 13, 1972, and the first train crossed the tunnel on January 31, 1973. The tunnel is 330 metres (1083 ft) long and 35 metres (115 ft) wide. The low grade required for trains makes necessary that each approach to the tunnel stretch be 4 km (2.5 miles). There was removed about 13,750,000 cubic meters (18,000,000 cubic yards) of material and construction of three viaducts on each side of the canal. As well, a solid earth plug had to be put into the

Welland Recreational Waterway The Welland Recreational Waterway is a water channel in the city of Welland, Ontario, Canada. It is an old alignment of the Welland Ship Canal that was abandoned after the construction of the Welland By-Pass in the 1970s. The Waterway is now man ...

(the old alignment of the canal), cutting it in two
satellite photo
. The construction cost was $40 million. The middle rail line was removed in the 1990s and the two remaining tracks now serve as the CPR Hamilton Subdivision and the CPR Brookfield Siding. Townline Tunnel is known locally as the "Stinky Tunnel" due to the strong odor of rotten eggs as one passes through it. The distinct smell of hydrogen sulfide that is sometimes present in the tunnel is created by dissolving layers of gypsum which are present in the bedrock of the area.

Issues with Flooding Control

Rain and snow falling on the approaches to the tunnel, as well as ground water flow, necessitate the operation of a pumping system to prevent flooding. Water is pumped via pipes located under the road and discharged into the canal. In February 1985, excessive runoff during a winter thaw caused flooding in the tunnel which closed the route to both rail and vehicular traffic. In late March, 2010, a routine inspection of the concrete pipes through which the water is pumped revealed erosion which threatened to cause a sinkhole within the road. The tunnel was closed to vehicular traffic to allow for repair. It re-opened April 22.

External links

Newspaper clippings about the tunnel's construction

References

{{Crossings navbox , structure = Crossings , place =

, bridge = Townline Tunnel , bridge signs = , upstream =

Highway 3 The following highways are numbered 3, H-3, PRI-3, AH3, E03 and R3. For roads numbered A3, see A3 roads. For roads numbered M3, see M3. For roads numbered N3, see N3. For roads numbered 3A, see 3A. International * Asian Highway 3 * Europea ...

/Main Street Lift Bridge (

Port Colborne Port Colborne is a city in Ontario, Canada that is located on Lake Erie, at the southern end of the Welland Canal, in the Niagara Region of Southern Ontario. The original settlement, known as Gravelly Bay, dates from 1832 and was renamed afte ...

) , upstream signs = , downstream =

,
Canboro Road ( Former Hwy 20),

Thorold Tunnel The Thorold Tunnel is an underwater tunnel in Thorold, Ontario, Canada carrying Highway 58 underneath the Welland Canal. Built between 1965 and 1967, the tunnel is 840 metres in length and consists of two separate tubes each containing two lanes ...

( Highway 58) , downstream signs = Canadian National Railway tunnels Railway tunnels in Ontario Road tunnels in Ontario Welland Canal Buildings and structures in Welland Transport in Welland Rail transport in Welland Tunnels completed in 1972 1972 establishments in Ontario