Seaway International Bridges over St. Lawrence River at Cornwall, ON

1962 North Channel: (Archived Bridge Hunter; Historic Bridges)

1958 South Channel: (Archived Bridge Hunter; Historic Bridges; Satellite, 14 photos)

South Channel.

CornwallSeawayNews, License: Creative Commons Attribution-Share-Alike (CC BY-SA) via BridgeHunter

This 2,480' (1061m) long bridge has a main span of 895' (273m). [HistoricBridges_south]

1958-2014 North Channel. The highest clearance was over the Cornwall Canal rather than the river.

Street View, Jul 2015

But the river had a fairly high clearance.

Street View, Jul 2015

The arched continuous truss main span is 414' (162m), and the length of the bridge is 5,350' (1631m). [HistoricBridges_north]

This bridge is also called the Three Nations Crossing because "an international Native American / First Nations reservation" is on part of the Cornwall Island. [BridgeHunter_north, HistoricBridges_north]

 

Photo from ezbordercrossing

2014 North Channel. The piers of the previous bridge have yet to be removed in 2017. Obviously, the girders are made with steel.

Street View, Aug 2017

The former south channel bridge is, in the foreground and the north channel bridge is in the background.

HistoricBridges_north

South Channel Predecessor Bridge

Chris Granger posted two images with the comment:

Cornwall, Ontario....September 6, 1898 and it was the day that a priest from Ottawa travelled to Russell and blessed the O&NY line.  Two hours later, which was also the amount of time photographer J.A. Noel finished his photos for the daily progression of construction for the St. Lawrence Bridges happened.  Just before Noon there was a loud sound of metal crashing against one another.  Noel went back to the south channel bridge and saw this.  Two of the three spans disappeared into the river, taking with it 15 souls and injuring 18 more.

The released report of what happened was that the Sooysmith Company did not properly find bedrock to build the piers.  What they thought was solid rock turned out to be 5 feet of gravel and beneath that was 20 feet of soft clay before bedrock.  Pier 2 collapsed from the weight of the steel work.  Phoenix Bridge Company was also found to be at fault.

A history tidbit, the centre span was found to be too heavy and the river current too swift to be retrieved so it was left in the river since the south channel did not have navigation ships use it and it was all but forgotten until 1957.  With the St. Lawrence Seaway using the south channel the bridge was removed (replaced with today's suspension bridge) and the dredges found the sunken steel work and had to get it removed before they could make the channel deeper for ocean ships.  Photos from the Cornwall Community Museum

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HistoricBridges_south, this webpage also has historical photos of the North Channel bridge.
"The former South Channel Bridge was opened to traffic in 1900....When both former bridges served vehicular traffic, they were called the Roosevelt International Bridges, a name given in 1934."