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When entering a parking structure in the Big Smoke have you noticed how there is generally a bar of some sort hanging from a couple of chains that you are required to drive under? There is also a sign that advises you the maximum vehicle height that can safely park in the structure. But, because people don’t like to read signs, or they don’t have a good sense of heights and numbers, the hanging bar acts as a check. If there is a bump as you pass under the bar you know that you have bigger problems ahead. Time to back up and park somewhere else.

So what do you think would happen if a parking garage posted the correct maximum height sign but set the bar a foot higher? Do you think people would look at the sign and think that the bar is set too high? Or would they simply ignore the sign and see if they fit under? If they are driving a vehicle that is a bit higher, perhaps a pickup truck with a camper unit on the back, they would probably inch forward cautiously, and once they passed under the hanging bar, assume they are okay and drive into the garage. Surprise!

This is basically the situation on William Street in Parry Sound and the CN trestle where there have been three ‘decapitations’ complete and partial in the past year. As you approach the trestle there is a frame structure about 15 feet in front of either side of the trestle. The sign on the trestle says that the maximum height is 10’6”. That seems like enough information to warn the truck driver with an 11’ height to take another route. What would you think if I told you that the clearance of the trestle, where the trucks hit the trestle, is greater than 11’, offering drivers a considerable margin of error. But perhaps 10’6” is actually more reasonable. As you look at the photo below you realize that there is a drop down as the truck travels under the trestle but the box of the truck would still be at the higher road level. That would lead to an angle which might actually make it an effective 10’6”, even if it’s actually three-quarters of a foot higher directly under the trestle.

The problem is not just professional drivers not knowing the height of their rig, or not paying attention, it’s also the support frame about 15 feet in front of the trestle. This structure has a clearance of 13’. I can well imagine that a truck driver might cautiously approach this 13’ frame and, discovering that they are able to get under it, assume they can fit under the trestle. It’s a bit of an optical illusion the way the road dips down, suggesting there is more clearance than there is.

The answer it seems is pretty simple. Suspend a bar on chains under the two support frames at 10’6”, much as you see in parking garages. A truck would pretty quickly figure out that they weren’t going to fit if they heard a thump well before they ventured forward and tore the top off their trailer.

We have had three such incidents just this year. You would think that CN would have figured it out by now that something needs to be done.

Has the Town received a formal report from CN attesting to the integrity of the trestle? Three dings in the past year and many more over the past few decades could mean there is unrecognized structural damage. But, it seems the railways always find it cheaper to apologize and make repairs after the fact than practice prevention.