Kellett started by making a prototype, or test version, of his invention. He had to get permission from local officials to install the test wheel alongside a dock.
The prototype consisted of a water wheel attached to a conveyor belt. As water turned the wheel, it also moved the belt. The conveyor belt carried the trash out of the water and into a large trash bin. When the current was weak, solar panels used the sun’s energy to power the belt (see How the Wheel Works).
Soon after the wheel was in place, people began to notice the river was looking cleaner. The wheel was doing its job!
There was just one problem. The harbor had much more trash than anyone expected. The wheel was not big enough to handle it all. “The concept worked well,” says Kellett, “but we realized we needed something bigger, stronger, and faster.”