Louis-hippolyte lafontaine bridge–tunnel

Lawrence River near Longueuil. The Louis-Hippolyte Lafontaine bridge-tunnel was built by the Government of Quebec between andnot only to connect Montreal to the cities of the south shore, but also to connect eastern and western Canada. The tunnel portion of the crossing is 1. The tunnel is the longest underwater tunnel in Canada and consists of two tubes, a central service corridor and two ventilation towers.

The retrofit involved completely updating the electrical system supply to 12 kV. Two new electrical rooms to house An Inergen fire protection system was used in the electrical rooms. Made with a combination of nitrogen, argon and carbon dioxide, the suppression system is an environmental alternative to replace halon. Named after Lower Canada political reformer Louis-Hippolyte Lafontainethe Lafontaine Tunnel is an immersed tube structure, measuring 1, m 4, It carries the Autoroute 25 expressway and passes beneath the main shipping channel in the Saint Lawrence River, immediately downstream from the Saint Lawrence Seaway.

In Montreal, to avoid having to build a huge bridge that would have disfigured the city and destroyed a neighbourhood, engineers opted for the construction of a tunnel located under the Saint Lawrence River and dug a trench under the river bed and buried the tunnel sections 4. The church in Longue-Pointe had to be demolished to make way for the tunnel, and families were expropriated from the village in Each of the seven tunnel sections weighs 32, t 31, long tons; 35, short tons and [ 3 ] is metres ft long, 37 metres ft wide, and is 8 metres 26 ft high.

In total, the bridge—tunnel is 1. The tunnel was built with sections prefabricated in dry dock and then sunk in the river [ 7 ] 24 metres 79 ft below the surface of the water. It louis-hippolyte lafontaine bridge–tunnel one of the largest prestressed concrete structures in the world and is the longest bridge-tunnel in Canada. Contents move to sidebar hide.

Article Talk. Read Edit View history. Tools Tools. Download as PDF Printable louis-hippolyte lafontaine bridge–tunnel. In other projects. Wikimedia Commons Wikidata item. Bridge—tunnel in Quebec. You can help expand this article with text translated from the corresponding article in French. December Click [show] for important translation instructions.

View a machine-translated version of the French article. Machine translation, like DeepL or Google Translateis a useful starting point for translations, but translators must revise errors as necessary and confirm that the translation is accurate, rather than simply copy-pasting machine-translated text into the English Wikipedia. Lawrence River, a buoyant concrete caisson for the southern eastern approach and ventilation building was prefabricated off-site, floated into place, and sunk into position just off the shore of Ile Charron.

A casting basin to protect the caisson was built behind an earthen dyke for the fabrication of the tunnel sections and ultimately the southern approach. Work on the casting basin, which extended north west from Ile Charron, was completed in May Workers then dug the trench to accommodate the seven immersed tube tunnel ITT sections that would comprise the main underwater tunnel.

The Ile Charron casting basin resembled one large floating assembly line. When each section arrived, it was placed at the end of the dock where the "assembly line" began. Assembly teams placed the concrete roadway deck and steel reinforcement bars inside each ITT section. The concrete and steel were placed carefully so as not to capsize the ITT section that was being floated.

When each section was finished, it was floated out by barge to the trench in the St. Lawrence River, and the next section was pushed up the "assembly line. Lawrence River in September ; the last section was immersed April To this day, the Lafontaine Tunnel remains the longest underwater vehicular tunnel in Canada. Conceived originally as a link in A before the Ville Marie Autoroute extension was shelved indefinitely, the bridge-tunnel complex has carried the A designation since it opened.

It was named in honor of Louis-Hippolyte Lafontaine, who was the first Canadian to become prime minister of Lower Canada. Trucks are restricted to the center travel lane because of lower clearances on the left and right lanes. In the early 's, the MTQ upgraded the electrical system serving the ventilation, lighting, surveillance, and fire protection systems.

From toconstruction crews carried out a major rehabilitation of the Ile Charron causeway approach that added a fourth southbound eastbound lane to A for exiting traffic. In the spring and summer ofthe Lafontaine Tunnel was closed on the weekends so that workers could repair concrete supports for the large basins positioned at the tunnel entrances; they also made additional repairs to the ventilation and electrical systems.