APAI on Ice Throw

John Harrison is a retired physics professor who knows a lot about forces and vectors.  He did some calculations about how far the 113-metre-diameter wind turbines planned for Amherst Island would routinely throw ice.  He followed them up with some examples of real-world measurements that supported his calculations.  The answer?  300 metres.  The ice sheets thrown that far could well be lethal – like 1kg traveling from 100 to 200 km/h!  Unfortunately there are many instances where the setbacks to neighboring properties or right-of-ways are far less than 300m.

Harrison’s paper is necessarily dense with numbers, so it is not an easy read for the general audience.  But his conclusions can be understood by all, and they are a reason for concern.


Harrison, Report on Potential Ice Throw

One thought on “APAI on Ice Throw”

  1. I read the whole thing, understanding the frightening possibility and assuming that centrifugal force is involved. In the Conclusion paragraph you advise the wisdom of a conservative setback of turbines from roads, buildings, homes and lot lines of 300 metres. Then you mention that as the ice falls off it will strike the ground at a speed of between 100 to 200 kph. Then the ice will break up into fragments that will not represent thrown ice. My question: would it be fair to say that ice fragments flying at high speed off the blades would be felt by a human being as being hit by bullets? or by stones? or – knife blades? Would these chunks be able to draw blood if they hit my head? Might one expect a concussion if struck by these ice fragments? Frightening possibility. And so close to the lot lines, too – why these fragments could actually strike a window, I assume, – might these ice bullets, or ice “stones” break the windows? In such weather it is safe to assume that children would not be playing near their lot lines, I would hope. These are not happy thoughts.

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