The goal of this test was to gather data on how higher tip speeds affect American eel (Anguilla rostrata) passing through an RHT. In this test, we spun the turbine at 980 rpm and peripheral speeds reached 28.2 m/s (63.1 mph).

As established in tests conducted by Alden Lab, there is a direct relationship between the length of a fish that can survive a turbine blade strike and the thickness of the blade that struck the fish. When fish length is similar to blade thickness, fish are slowed (up to 30%), and their bodies conform to the blade shape, pushing them away from the leading edge before impact.

In this test, we used small (106 to 270 mm / 4.2 to 10.6 in) eels with our smaller (.55 m / 1.8 ft) test turbine to match the fish length to blade thickness ratio that would be present at a full-scale hydropower site through which full-grown (400-800 mm / 15.7-31.5 in) eel were migrating downstream.