A riprap The entire Laviolette Bridge is useless, because a drifting ship would run aground before hitting the ends of the bridge, due to the shallow depth of the water there.
In the 1970s, studies identified it as a very fragile structure. […] On the other hand, the pillars of the bridge were filled with rock in the 1980s to avoid collisions with ships.
A quote from Pascal Desrochers, president of the Corporation despilotes du Saint- Laurent Central
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Six people still missing, says Maryland governor
ELSEWHERE ON INFO: Six people still missing, says Maryland governorLoading in progress
Six people still missing, says Maryland governor
ELSEWHERE ON INFO: Six people are still missing, says the governor of Maryland
In Quebec, the pillars of the bridges are on the shore, very far from the navigation channel, while in Montreal, ships circulate in the seaway and therefore cannot deviate from their trajectory. Approximately 6,000 vessels transit the St. Lawrence River each year in the Central St. Lawrence Pilot Area.
Only the Jacques-Cartier Bridge, between Montreal and Longueuil, is an exception, but the volume of the pillars, the reduced navigation speeds (around 6 knots) and the more modest size of the ships mean that the impact force n&# x27;would have no common measure with what happened in Baltimore, according to Pascal Desrochers.
Furthermore, around the only pillar of the Jacques-Cartier Bridge submerged in water, the depth of the river is relatively shallow and a large ship would likely run aground before hitting the pillar.
In the transport sector Jacques-Cartier Bridge, reduced navigation speeds, in particular, would reduce the force of impact.
The carrier Dali containers, which collided with Baltimore's Francis Scott Key Bridge at 1:30 a.m. Monday night, measured 1,000 feet long, 150 feet wide and could carry up to 16,000 tons of cargo.
Bruno Massicotte, professor in the Department of Civil, Geological and Mining Engineering at Polytechnique Montréal, also notes that the Baltimore Bridge appeared to lack protection around its piers. In an interview, he emphasizes that in Canada as in the United States, federal laws govern maritime requirements. Afterwards, he adds, it is up to the owner of the bridge to meet these requirements.
Why 'riprap was not done in an area as busy as the Baltimore bridge? This is a good question, added the professor, mentioning that, according to him, it is a prevention problem which was not taken strictly enough.
At the time of publication, six people were carried disappeared in the Patapsco River which runs along the Maryland metropolis.
With information from Mathieu Papillon and Éric Plouffe