How do contests load and test a bridge?
Common loading setups: a hook or eyebolt at mid-span, a loading block or plate, buckets of sand, and what to check so your bridge works on the test rig.
Updated · 1 min read
Short answer: most hang a weight from the middle of the bridge, through a hook, an eyebolt or a loading plate, and add weight until the bridge fails or a cap is reached. The details vary, and they can decide your design.
Common setups
- Hook or eyebolt through the deck. The bridge needs an opening or attachment point at the load position.
- Loading block or plate. A small block sits on or under the bridge, with a rod through it, and the load hangs from the rod. Rules limit the block's size.
- Platform or roadway on top. The load rests on a deck or platform you provide.
- Bucket of sand or weights, added in steps, or a hydraulic or screw rig that pushes or pulls.
- Supports. Two stands or blocks set the span. The bridge may rest on top or hang between them.
What to check
- Where the load goes, and how the bridge must connect to it.
- Whether the bridge must leave a gap or opening for the rod, a plate or a car.
- How the supports hold the bridge. Does it simply rest, or may it be fixed?
- What counts as failure: breaking, bending a set distance, or touching the floor.
Match your practice rig to these details. See testing safely and reading your rulebook.