Actually not the weight, but the height / clearance.
Having read the recent thread on bridge strikes, It reminded me at least one of our illustrious members has a talent for second guessing the real clearance on a bridge.
Rather than getting some steps and a tape measure, I’m blanking the signage on some bridge images and posting a poll to let you guess the marked clearance.
I don’t know how I could post a set up in one go, so this will grow a little over time. Feel free to add some yourself. If the forum still stops you posting more than 3 posts back to back, I won’t be able to keep going without someone posting in between.
That would help, but I also recall that the correct conversion from metric to imperial has caused some dispute, so it might be safer (plus easier) for me to keep with what I’ve blanked out from the image.
Here’s a table I’ve grabbed from a quick google, I hope it’s contents aren’t controversial to anyone…!
The odd thing with bridge signange, that I’ve just seen when doing the image for bridge 4, is when they have metric and imperial on the sign, they don’t look to match one another.
I think there is some rounding done once the leeway from the signed clearance and the actual clearance is worked out. On that bridge, you would think that the metric figure is 7cm too low.
This is the argument that is caused by converting between one system of measurement and another. The issue as you say is caused by rounding errors as well as incorrect conversion factor.
the other issue i guess is the safety margin. 1 inch is 2.54 cm lower that to 2.5 cm and you can be 7 cm out
So, I do have the imperial height that is on the sign in the poll. If you take that figure to the conversion table posted, the metric figure you come back with is 7cm more than the metric figure blanked off the sign.
It does become a bit baffling, and makes you wonder why they wouldn’t add 2 inches to the imperial figure…!
This one has a different height signed on the opposite carriageway. They have also had the road up here recently, so may now be a different height, or matching on both sides. Image circa 2019.
Edit : I retract the statement that the other side of the bridge is signed a different height, as google street view doesn’t back me up…!
