This old rake-looking contraption is the Niagara Falls Powerhouse Ice Drag, originally used to pull ice chunks off of the top of the water before they could enter the power station. Many thanks to my friends Mint and Cado for helping identify this and track down some details! More information here: https://web.archive.org/web/20171224065630/http://www.niagarafallsreview.ca/2013/09/04/niagara-falls-powerhouse-ice-drag-on-the-move