Watch out Bonnie, there might be big propellers under the water in the East River.
A company that seems to have some trouble designing cast aluminum turbine blades has installed a small number of test turbines in the East River. The currents are so strong that several of the turbine propellers have been sheared off a third of the way down, and stronger replacements were hampered by insufficiently strong bolt connections to the turbine hubs. The East River is not actually a river; it's a tidal strait, and one can easily observe the current moving in opposite directions with the tides. The plan is to install a field of turbines anchored to the bottom of the East River and use the currents to generate electricity for the city.
It is worrying when the founder of the company, Trey Taylor, thinks that: "The only way for us to learn is to get the turbines into the water and start breaking them." The trial turbines — five generating electricity and one housing the dynamometer that measures water rotational speed — have been installed on the bottom of a narrow strip of the river’s eastern channel.