The Problem
Bridges and cable trams on West Coast Trail can fail if overloaded. The weight of a hiker and his/her pack could overstress a crossing.
The Assignment
Design and build a weigh scale to be placed at either side of bridges and cable trams on the West Coast trail. The scale must be accurate, lightweight (someone has to carry it in), and cheap (lot of crossing points).
The basic idea was to have a beam deflect with the weight of a person carrying a backpack. Strain gages on the beam would be calibrated to provide three signals: GO, STOP or USE CAUTION. The scale shown to the right was meant to be hung from a tree. The hiker would sit on it.
One or two people would stand on this scale.
The bridge at the West Coast trail.
Students testing the weigh scale.
Device being “stress-tested” by Pierre Bérubé, one of the instructors.