I've written before about the icemaking process. This post is about ice removal. Once ice goes in for hockey in September or October, the only time it comes out is for the circus. For all other shows it is covered but the circus needs to access tie-in points in the concrete.
To remove the ice, the compressors are turned off and "downdraft" fans are turned on to push the heat from the ceiling down at the floor to facilitate melting. It actually starts melting pretty fast. Once it 'pops' then it's time to take it out. Basically the pop us just the melting process at the point when the ice bond to the concrete below is broken.
Then, bring in the Bobcat. I've done ice removals before where we just let it melt and then cleaned the floor by a massive spray-down with a fire hose. The Bobcat method is not only quicker, but it conserves water. I did not participate in the removal that happened March 1, 2009 but I did get pictures of the aftermath.
You can see the giant piles of ice that was sheared up by the Bobcat and deposited outside the southeast corner of the building:
You can see that from the chunks that it is not terribly thick. Ice acts as an insulator; in fact an inch of ice has about the same insulation qualities as an inch of pink fiberglass attic insulation. Yes it is cold, but the raw insulation factor is about the same. So if you let the ice build up too think, it actually insulates against itself whereby the top of the ice is too far away and too insulated from the cold pipes below, so the top stays soft and slow to skate it.
Here are close-ups of just how thick (well, thin, actually) the ice is:
Keep rooting for the Cyclones while they are on the road for the next two weeks, then be sure to come out for their homecoming March 18!