On a cool, cloudy, but so far precipitation-free Saturday in Chicago, the NHL Ice Crew continues its work. The huge team logos on each side of the “little rink” are in place. The penalty boxes and team benches are almost finished. The poles that will hold the nets at the end of each side of the rink have been installed.
The challenges of making ice on an outdoor rink are different from those on an indoor rink. “This ice has to freeze from the bottom up,” noted NHL Facilities Operations Manager Dan Craig. (Usually, the process is to freeze from the top down, but a temporary outdoor rink has to be done this way.) “You need absolute solidity from the bottom so as not to get air-bubbles or what we call ‘shell ice.’”
In order to keep that new ice frozen, the crew has installed a state-of-the-art refrigeration system below the aluminum panels that will hold the eventual ice surface. This system, which will deliver some 3,000 gallons of coolant from a truck outside the stadium, is intended to remove all heat from the aluminum and ensure that the temperature of the metal never threatens the integrity of the ice.
This weekend, Craig and his crew intend to flood the both game rink and the auxiliary rink and use their two new Zambonis slowly, in layers, adding and adding new layers of ice. The crew can make one inch of ice in a 24-hour period, so there’s plenty of time to manufacture two inches’ worth before workers are scheduled to paint the ice on Dec. 27.