Bridge Testing Machine
This machine was used for the Bridge Building Challenge at the RIBA Family Fun Day in April 2016.
A contestant's bridge was placed across the end supports, and possibly held in place if it was very light.
The testing machine was then placed in the middle and its feet adjusted so that there was a slight gap between the bridge and machine. The bridge was then loaded up with nuts and bolts until it flexed enough to activate one of the four tactile buttons inside the machine, lighting an LED and sounding a buzzer.
After the nuts and bolts were weighed, and the weight of the bridge was also taken into account, each contestant's bridge could be given a score.