“The Perfect Sheet”

Zamboni operators’ quest for perfect ice

Matt Gilmore, sitting behind the wheel of a Zamboni
Matt “Happy” Gilmore smiles behind the wheel. Zamboni-driving takes focus, but Gilmore says that he loves waving to children in the crowd and making their day.
Photograph by Jim Harrison

Matt Gilmore sits straight up on the Zamboni’s elevated seat, his left hand guiding the steering wheel, his right controlling the water spurting out the machine’s back. He leans leftward, his eyes trained on the few inches of space between the vehicle and the boards. Hitting the wall with the five-ton machine would be one of the worst things he could do, but his 14 years of experience ease the concern. “Once you’ve done the pattern for long enough, you can basically do it with your eyes closed,” he says. But Gilmore’s focus is palpable as he handles the Zamboni; a self-described “social butterfly” and popular figure at the Bright-Landry Hockey Center, he’s noticeably less talkative behind the wheel. He doesn’t even seem to notice the half-dozen people who have gathered to observe the legendary vehicle in action.

The quality of the ice affects the quality of the game. Bad ice—chipped, slushy, sticky—can lead to slow skating, errant passing, sloppy attacking, and even broken bones. Highly variable ice conditions are a problem that has plagued the National Hockey League for decades. Some of the world’s best players find their speed and skill squandered on rough ice. Quick, precise exchanges are easiest when the ice is level, smooth, and cold (but not too cold).

On a Thursday afternoon, rink manager Scott Anderson and Zamboni operator Gilmore perform “ice maintenance.” During this three-hour period, they restore the rink to ideal conditions, repairing any spots affected by the gradual wear-and-tear of hockey, figure skating, open-skate sessions, and even broomball—each of which leaves different “scratch patterns.” Figure skating produces divots and holes, but hockey produces a more even shave of the ice, with the most wear in the rink’s center.

Anderson and Gilmore begin by drilling 23 holes into the ice at specific locations, to measure its depth. If a spot’s too high, they’ll shave it with the Zamboni. If it’s low, they can “flood” the area with cold wash water. Anderson, who’s been working at Harvard since 1978—as the head men’s lacrosse coach between 1988 and 2007, director of athletic facilities, and assistant director of athletics for facilities and operations—knows how high the ice should be kept at each spot. Because the concrete base beneath the rink is not completely even throughout, the ice thickness ranges from about one to one-and-a-half inches. Within the concrete, glycol-filled pipes keep the surface stable and quickly freeze any added water to between 20 and 22 degrees, the hockey coaches’ preferred temperature. Figure skaters tend to prefer a temperature in the mid-to-high twenties for softer landings, but colder ice makes it easier for hockey players to push off and fly down the ice, and creates less slush. A temperature in the teens could mean brittle, easily fractured ice.

At Harvard, ice maintenance is slow and regimented, with an eye toward perfection; just before the game is not the time to make major adjustments.


Before the Zamboni’s invention in 1949, rink employees would attach a scraper to a tractor, and then drive the machine around the ice. A few workers followed the contraption, swept away the shavings, squeegeed the surface, and sprayed on a new layer of water. Lacking a tubing system beneath the ice, they had to wait for the water to freeze naturally; the process took more than an hour. The Zamboni revolutionized ice resurfacing, cutting the total time to around 10 minutes, and removing the need for a team of dedicated squeegee men. It’s become so popular that Zamboni (the name of inventor Frank Zamboni’s company) has become the de facto name of the machine for those unfamiliar with its less catchy, technical name: ice resurfacer.

The machine itself is a picture of efficiency. A long, heavy, razor-sharp blade shaves a thin layer—typically about one-thirty-second of an inch—from the ice’s surface. A horizontal auger gathers the shavings and pumps them into a vertical auger, which sends them into the snow tank. Cold water is fed from a wash-water tank to the “conditioner,” which rinses the ice as dirty water is vacuumed, filtered, and returned to the tank. Finally, warm water is delivered through a pipe, and spread by a cloth towel across the floor, which gives the ice its glossy, even coat. “The ice resurfacer is really a brilliant machine,” says Zamboni operator Joe Marrero. He takes the responsibility of driving it seriously: “I’ve been here for 14 years. It doesn’t matter how much you perfect it. I get anxiety every single time.”

On a Friday night two hours before a women’s hockey game against Quinnipiac, Marrero, Gilmore, and a small group of others prepare for action. Once all the youth-hockey athletes clear off the ice, two men remove the goals, and Marrero backs the firetruck-red Zamboni around a tight corner, ducking his head under a metal gate as he approaches the ice. He heads straight for the boards, angling himself parallel to them, a fingertip away. “He’s about as flush as he can be,” Gilmore tells me from behind the glass. “Joe’s been doing it for a long time, so he has a big range.” As he slows down on tight turns, he decreases the rate of water delivery, making sure the machine’s speed variation doesn’t affect the evenness of the ice. Marrero hopes to hit the sweet spot: a nine-to-10-minute ride, with clean passes (not much overlapping), that uses about two-thirds of the machine’s water and fills up about three-quarters of the hundred-cubic-foot snow tank. This time, he nails it. “The ideal sheet,” he announces as he pulls into the garage. “Three-quarters.”

The crew stays vigilant as the game continues. Commercial breaks and time-outs are a good time for a quick sweep in front of the benches and goals. When a Quinnipiac player tumbles into the Harvard net, knocking it out of place, Gilmore runs on to re-anchor it in two flexible Marsh goal pegs. The 15 minutes between periods present the greatest stakes. As Marrero sits in a back room, filled with extra clothing, shoes, and boots, Gilmore sticks his head in and nods, indicating the second period’s end. About two minutes later, when the “Chuck-a-Puck” challenge is over and the crowd’s rubber pucks have been cleared off the ice, Gilmore nods again and Marrero climbs atop the Zamboni. This time he completes his rounds in a tight seven and a half minutes. Given the time restrictions, it’s a good shave.

After 60 minutes, Quinnipiac comes out on top, and the ice, thankfully, has played no part in the outcome. Most of the crew leaves, and after about 14 hours straight at the rink, Marrero does too. Gilmore, the last man standing, is proud of their work tonight. “For me it’s fun,” he says, “It’s an honor. You’re being trusted to make ice for a nationally televised game. I know it’s not a big deal, but it is in my eyes.” He takes out the Zamboni one last time. The nine-minute ideal-sheet time comes and goes, and he’s still on the ice, traveling in neat concentric ovals. As he pulls back into the garage, he explains that he did two ices in a row, filling the whole tank completely with snow. I check my stop-watch: 18 minutes—perfect timing for two flawless, glistening sheets.

Read more articles by: Jacob Sweet

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