After spending the past seven weeks designing and constructing bridges, Shepparton Christian College students tested their work.
Using only bulsa wood, glue, string and hard cardboard the best bridge absolutely dominated the afternoon.
Built by Year 9 students Caroline Gigimon and Shana Scanlan, their bridge was so strong it needed to be force broken.
Filling a bucket with sand and bricks weighing 27kg was not enough.
Using all of his force, science and math teacher Caleb Milburn said the bridge gave way at about 41kg.
Other bridges went down around 10kg and second place snapped at about 18kg.
The winners said it was "amazing" to reach well above their expectations of 20kg.
They reckon the trick was the joint design and use of cardboard.
The students were assisted by engineering contractor John Holland during the past few weeks.