A channel of green water is adjacent to a steel surface protruding from the water at a 45 degree angle. This steel surface is a series of metal grates that prevent ice, trash and debris from entering the penstocks below.

Ice And Trash Racks in Forebay Nov 23, 2006

This is the last line of defense for the turbines!

Ok, maybe a bit dramatic. These racks prevent large chunks of ice (and other debris) from entering the penstock and falling down into the turbines where they can damage the blades.

Rankine had more problems with ice than the Toronto Power Company station, primarily because the water had to make a 90-degree turn before entering the forebay. The Toronto Power Company station was positioned advantageously directly on the Niagara River's edge (apparently due to better political connections at the time). While ice was still a problem at that station, it wasn't to the same degree as it was with Rankine.

Upstream, the Toronto Power Company power station is located adjacent to the Niagara River. Further downstream, a weir directs water at a 90 degree angle to the river, towards the outer forebay of the Rankine power station. — **Power stations on the Niagara River:** The Rankine power station requires its water to make a 90-degree turn before entering the forebay. This changes its speed and increases the likelihood of ice buildup. The Toronto Power Company station (located further upstream) is directly adjacent to the river. This limits the number of ice problems compared to Rankine station. (Archival photo from 1937)