A European-style immersion tunnel seems to offer a viable and cost effective option
To the Expositor:
How long do the people of Manitoulin have to wait for a reliable passageway on and off the Island? Once again our poor old bridge is in trouble. It’s not the main bearing this time, and the asphalt doesn’t need a touch up. The new computer controls seem to be operating as they should, but the darned thing is having trouble locking into the “closed” position ( enabling vehicles to safely cross to and from the Island).
According to the recent article in The Expositor, one of the eight iron wedges that lock the bridge into the “safe” position has suffered from metal fatigue and needs to be replaced. Having been in service for 103 years this is hardly surprising! But how long until any of the remaining seven suffer the same fate?
And so we are restricted to the number of ‘swings’ the bridge can make for the busiest time of the year. Car and truck drivers will be thrilled but boat traffic between the North Channel and Georgian Bay will be hugely inconvenienced. If a total shutdown occurs in either the ‘open’ or ‘closed’ position it would be a disaster for everyone.
Is it not time for someone to start planning for a replacement? One reads of the remarkable advancements in tunnels being built in Germany, Denmark, the Netherlands and the U.S.A.
These “immersion tunnels” are built in sections on land, floated off into the water and sunk in a pre-dredged channel which has been blasted out of the river-bed. There they are securely fastened together. They are made either of steel or re-enforced concrete and provide several advantages over ‘above water’ options:
1. They are cheaper than ‘fly-overs,’ lift bridges or other types of structures;
2. They are safer to build than bored tunnels particularly with our limestone base;
3. There is no winter maintenance;
4. There is no ‘wait-time for either maritime traffic or vehicles (most sections are large enough to allow two traffic lanes); and
5. Our iconic old swing bridge could be safely anchored in the ‘open’ position and left in peace to remind our grandchildren of what we had in the old days.
Bill Caesar, bridge enthusiast
White’s Point
