Gary S' 2010 Summer Challenge - Bridge

[Gary S]

In your photo, with the red arrows, the legs are equidistant at the top, and the two to the left show as angled out at the bottom. Model what you see, there's a reason for the angled legs. Look at any timber trestle, you'll see the same thing.

But the odd thing is the asymmetry from one side to the other. And also the asymmetry from bent to bent. And then there is the asymmetry between the spans. The three spans on each end are 25 feet, the four in the middle are 35 feet. The middle three bents at the 35 foot spans are doubled fours, but the two on the ends of the 35 foot spans are single fives. And the other ones under the 25 foot spans are single fours. I'm sure it is all based on sound engineering practice.

RE: length of bridge:

Thankyou for the verification. I used your Xacto knife as a reference to determine the width of the model, and then used the width to determine the length. That I got so close to your determination of the prototype length, verifies the process. I got 40" which converted to 290'.

Great method on determining the length. I've been using similar methods with the bridge photos to determine dimensions.