Third link: Go 80 meters underground for the bus

If this ever happens, the Quebec-Lewis tunnel will force public transport users to descend to a record depth of 80 meters to pick up the bus.

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Those who want to cross the river via the “third link” on the electric bus can do so from the platforms of the incredibly shallow “Parliament Hill” station, which is the equivalent of twenty floors underground.

By comparison, the average depth of Montreal metro stations is 15 meters. The deepest is the Charlevoix station, which is 29.6 meters underground.

The deepest in Canada will soon be the Edward-Montpit station of the REM (Riso Express Metropolitan). With 72 meters of rails underground, it becomes one of the deepest in the world.

Up to 80 meters underground

However, the Quebec-Lewis tunnel puts the capital at risk in Montreal. MTQ confirmed to our Bureau of Investigation that Parliament Hill Station next to Complex G “reaches a depth of 70 to 80 meters”. It is impossible to be more specific at this point.

Two sections of the Risso Express de la Capital (REC) meet there, each in its tunnel: the tunnel’s electric bus and the Quebec City Tramway, which also tunnel the lower town to a depth of 15 to 40 meters.

Pierre Brissett, a retired architect who studied topographic maps of the area, believes that the station near the National Assembly is deeper than the MTQ claims. Parliament Hill sits on a rocky plateau 85 meters above river level.

Slope of 5% to 6% in the tunnel

Mr Brisette also stressed the extent of the challenges associated with the construction of the under-river tunnel – particularly worth between $ 6 billion and $ 10 billion due to the slopes. The Ministry has confirmed to us that the slopes are “5 to 6%”.

“150m drop, for this kind of structure, I have not seen anywhere else on the planet. », Retired Architect Note, The construction of a bridge reserved for public transport between the two city centers and two other road bridges on the east through the island of Orleans will allow many billions in savings.

The Legalt government, which has not yet released any study on the other options analyzed, said in its part that the 8.3-kilometer tunnel between the two city centers was the best solution.

Steep slopes do not pose a problem, one assured us, “comparable to what one found on the Henry-IV road” between Charest and Hochella. Truckers have no access to the tunnel during rush hour, which is specified to ensure traffic flow.

The depth of Parliament Hill Station, “does not represent a major technical challenge”, has been argued to be due to the expertise gained with REM.

The deepest subways in the world

• Pyongyang Network (North Korea): 110 meters
• Station Arsenal, Kiev (Ukraine): 105.5 meters
• Hangtudi Station, Chongqing (China): 94 meters away
• Admiralty station, St. Petersburg (Russia): 86 meters away
• Victoria Park Station, Moscow (Russia): At a distance of 84 meters
• Washington Park Station in Portland, Oregon (United States): 79 meters away
• EM Dowd-Montpit Station of the REM, Montreal (Canada): 72 meters (* Under construction)
• Charlevoix Station, Montreal (Canada): 29.6 meters

The longest road tunnel in North America

Much has been said about its width, 19.4 m above its planet. Simple and unique with, but so far very little about its length. However, the Quebec-Lewis tunnel seeks another record, the longest road tunnel in North America.

At 8.3 km, the tunnel proposed by the Legalt government will be twice as large as the current record holder in Alaska.

An hour from the American state capital Anchorage, vehicles and trains alternate on the single track of the Anton Anderson Memorial Tunnel, which is approximately 4.2 km long.

Elsewhere in the world, mainly in Asia and Europe, nearly fifty road tunnels are already 8 km long. The tallest, Lorddall in Norway, was built 24.5 kilometers away.

The tunnels, intended specifically for train travel, are in their own classroom. One of the most famous, more than 50 km below the channel (between France and England). The Great Champion, the St. Gotthard Railway Tunnel in Switzerland is 57.1 km long.

“Too much risk” project

Engineer Bruno Masicot was also among those who publicly questioned the choice of an under river tunnel connecting Quebec and Lewis, saying the project was “too risky”.

The technical challenges of this massive project – which could break many records worldwide and in America – are many. He warned that while they could not be overcome, obstacles would come at a very high cost.

“It’s big … there are limits to pushing technology at some point. Yes, we can go to the moon, but it is expensive. Everything is doable, it’s just a question of costs […]If we want to do anything financially, a large tunnel (19.4 meters in diameter with a single pipe) is probably not the best solution, ”said an expert from the Polytechnic de Montreal in an interview.

Bruno Masicot has known what he is talking about since a feasibility study on a tunnel in 2016 on behalf of the Coillard government. Five years ago, at the request of the MTQ – the only corridor studied was further east below the peak of the Old de Orleans.

Mr. Masikot has already stressed that such a project is “risk”, confirming that it is possible for about 4 billion. Keep in mind that the current project connecting downtown Quebec City and Lewis will cost two and a half times more.

Two tunnels instead of one?

The engineer was instructed to focus specifically on a two-pipe project instead of a huge monotube with six lanes on two floors, the largest in the world.

“To beat such a record, you really need to and make sure that this is definitely the only solution and that this solution is very profitable. […]I have big doubts. ”

Like retired architect Pierre Brisset, Mr. Masicot also argued that securing a two-level tunnel with entrances and exits was too difficult. He argues that even government engineers refused to consider the monotube option five years ago.

“Two submissions need to be made: one large tunnel or two parallel tunnels,” he suggests. Both tunnels cost much less and have a lower risk than the larger tunnel. “

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