Friday, January 21, 2011

Celebrating Frank Zamboni

We can't resist watching the Zamboni at work...

There are three things in life that people like to stare at: One is a rippling stream, another a fire in a fireplace, and the other is the Zamboni going around and around and around -- Charlie Brown

Today, like "Kleenex" for tissue and "Xerox" for photocopying, Zamboni is the generic name most people use to descibe ice resurfacing machines.

No matter how well-groomed the ice rink, the ice will eventually be cut and pitted, and dust and bugs will dull it. The ability to quickly and effectively resurface the ice is as important to skating as the development of indoor ice itself.

Before ice-resurfacing machines, ice rinks were resurfaced manually, using scrapers, towels, a water hose and squeegees. Resurfacing a regulation-size rink was time-consuming and labor-intensive. In the 1940s, Frank Zamboni began to experiment with building machines that would shave, scrape, wash and squeegee the ice surface all at once before putting down a fresh layer of water.

Early ice-resurfacing machines cost about $5,000 and were built by hand on war-surplus jeeps. Today, ice-resurfacing machines cost significantly more (about $55,000), are mass-produced, and every rink has at least one. Professional hockey teams, including the Carolina Hurricanes, routinely use two machines to cut down on the time needed to resurface the ice between periods. Most ice-resurfacing machines have a maximum speed of 9 to 10 mph (14 to 16 kph) and weigh between 5,000 and 6,000 pounds (2,300 to 2,700 kg)!

The NHL requires that two machines resurface the ice between periods. The ice is resurfaced before the game, after warm-ups, between periods, during playoffs, and when the game is over. With two resurfacing machines, it takes three minutes to complete the floor, each making four full passes up the ice. With one, it takes between six and seven minutes with eight full passes up the length of the ice.

The basic driving pattern is a clockwise motion of slightly overlapping ovals. MacMillan says that he uses 80 to 100 gallons (300 to 380 liters) of heated water between periods to resurface the ice. "With both machines," says MacMillan, "we can scrape about three-quarters of a bucket during each game."

While MacMillan's Olympia machines have an 84-inch long, 1/2-inch thick blade, most Zamboni machines have a 77-inch long, 1/2-inch thick blade (A). The blade scrapes a 1/16-inch to 1/8-inch layer of ice off the ice surface. The blade runs the width of the machine and looks like a thick razor blade. The amount of ice taken off depends on the ice conditions. The rougher the ice surface (i.e., the more use it has had), the deeper the blade cuts.

Just above the blade is a horizontal, rotating screw, or auger (B). The auger gathers the shaved ice, or snow, and rotates it up to a vertical auger (C), where a spinning blade picks up the moving snow and throws it into the bucket (D). The bucket can hold an amazing 2,600 pounds (or 300 gallons) of snow!

Under the bucket, there are two tanks of water, one for "washing" the ice as it's shaved and one for making ice. As the resurfacing machine moves over the ice, the blade shaves layers of the ice off. Water from the wash-water tank (E) is pumped over to a cleaner (F) that blasts the water into the deep cuts in the ice and forces out dirt and debris. The excess water left on the ice is squeegeed off with a rubber blade (known as a towel) at the back end of the machine (G) and vacuumed up. The hot water loosens the crystal structure of the old ice underneath, so the new ice will form a solid bond with the old ice, instead of a separate layer that chips off easily.

The last step is to resurface the ice. Warm water from the second water tank is pumped over to the squeegee blade and spread evenly over the ice. This softens and fills in the deep cuts in the ice and helps to even out its surface.

After the final pass on the ice, tbe uce-resurfacing machine returns to its garage. At this point, the snow bucket is raised and the snow is dumped into the snow pit. As the snow melts, the pit is drained.

Some Ice Milestones

* 1876: The first indoor ice rink opens in London. The ice is made through an expensive process of sending a mixture of glycerin and water through copper pipes.

* 1879: The first indoor ice rink in the United States opens in Madison Square Garden in New York City, NY.

* 1908: The first Olympic figure-skating competition is held on a refrigerated indoor rink as part of the Summer Games in London.

* 1976: Ice dancing becomes a Winter Olympics sport.

Years before hockey or the Winter Olympics, ice skating was a means of getting across the frozen waterways in northern Europe. It was only when ice became available year-round that sports such as hockey and figure skating took off.

The success of modern ice rinks owes a lot to Lester and Joe Patrick, two brothers who created hockey leagues in Canada in the early 1900s. On Christmas Day 1912, the brothers opened Canada's first indoor ice rink in Victoria, Canada. The arena cost $110,000 to build and seated 4,000 people. Three days later, the Patrick brothers opened another arena in Vancouver, Canada. This was a more expensive arena -- $210,000 to build -- and it could hold more than 10,000 people. Underneath the ice was the world's then-largest refrigeration and ice-making system.

Over the next few decades, the Patricks were responsible for creating arenas all across the northwest United States and throughout western Canada. Today, the United States has more than 1,700 ice rinks. New arenas today can cost hundreds of millions of dollars to build.

The underlying technology behind indoor ice rinks is the same technology at work in refrigerators and air conditioners.

Other than sheer size, the main difference in an ice rink is that the refrigerant doesn't cool the ice directly. Instead, it cools brinewater, a calcium-chloride solution, which is pumped through an intricate system of pipes underneath the ice. In most rinks, the pipes are embedded in a concrete or sand base.

To freeze the rink surface, the system pumps 9,000 gallons (34,000 L) of freezing brinewater through the pipes and then onto the ice-bearing concrete slab.

The brinewater is pumped into the pipes embedded in the ice-bearing concrete slab. The ice-bearing slab sits between the skating surface and a layer of insulation which allows the ice to expand and shrink as temperatures and time demand. The brinewater helps keep the ice-bearing slab's temperature just below 32 F so that the water spread onto it can freeze.

Underneath the layer of insulation, a heated concrete layer keeps the ground below the ice from freezing, expanding and cracking the rink structure. The entire rink sits on a base layer of gravel and sand which has a groundwater drain at the bottom.

To defrost the skating surface, the brinewater is heated and pumped through the ice-bearing concrete slab. This heats the under layer of the ice, making it easier to break up and remove with front-end loaders.

It takes between 12,000 and 15,000 gallons (45,000 to 57,000 L) to form a Hockey rink surface. The maintenance crew forms the ice in several different layers, in many steps:

1. The crew sprays the first two layers on using a paint truck. The paint truck creates a fine mist of water to create the first two layers, each only 1/30 of an inch thick. The first layer freezes almost immediately after it is sprayed on.

2. Once the first layer is frozen, the crew sprays on the second layer.

3. The crew paints the frozen second layer white with the paint truck, allowing for a strong contrast between the black hockey puck and the ice.

4. The crew then sprays on the third layer. This layer, which is only one-sixteenth of an inch thick, acts as a sealer for the white paint. The crew paints the hockey markings (the lines, creases, face-off spots and circles) and team and sponsor logos on top of this third layer.

5. Once the markings and logos dry, the crew gradually applies the final layer.

The crew slowly applies the remaining 10,000 gallons with a flooding hose. "We put on 500 to 600 gallons per hour until the remaining layer is complete," says MacMillan. "That means 15 to 20 hours (1 hour/500-600 gallons) for that final layer. Each of those layers is allowed to freeze before we put the next 500 to 600 gallons on. The less water you put on the floor at one time, the better your ice will be."

Temperature: Good Ice vs. Bad Ice

Brand new ice is called "green ice" because it hasn't been broken in yet.
When creating a new ice surface, indoor conditions are very important. MacMillan says he likes to "keep the skating surface at 24 to 26 F (about -4 C), the building temperature at about 63 F (17 C), and the indoor humidity at about 30 percent. But if it's warm outdoors and we have an event where the doors are open and all that warm air comes in, then we have to adjust it. Even one degree can make a big difference in the quality of the ice."

An indoor high humidity can create a fog over the ice. A Raleigh, N.C. arena has more than 770,000 square feet, and requires 12 dehumidifiers throughout the building to keep the air dry indoors. The outdoor temperature can also affect the ice conditions. The arena and ice temperatures must change to compensate for the heat and humidity that will come in when the arena doors are opened to fans and spectators.

Many NHL players have expressed concerns about ice conditions in very warm-weather cities during the Stanley Cup playoffs. They fear the outdoor temperature may be hot enough to soften the ice inside the building. In Canada, the problem is just the opposite. The buildings often have to be heated because the extremely low temperatures outside can cause problems with the ice.

Ice conditions can vary greatly with a temperature change as small as one degree. The type of water also can change conditions. For example, ice made with water that contains dissolved alkaline salts may have a sticky feel to it and will dull skate blades. To counteract these problems, many rinks -- including the Raleigh arena -- use water purifiers or add chemical conditioners to tap water.

Figure skaters and hockey skaters have different ideas of what good ice and bad ice are. Figure skaters prefer an ice temperature of 26 to 28 F. Ice in that temperature range is softer, so it grips the skate edges better. It is also less likely to shatter under the impact of jumps. Hockey players, though, prefer colder, harder ice. With many skaters on the ice simultaneously, it's easy for the ice surface to get chewed up at the temperatures preferred by figure skaters. For hockey games, the top of the ice is usually kept at 24 to 26 F. Ice that's too warm might cause players to lose their edge during a crucial play, but ice that's too cold may chip too readily.

Painting the Ice

Water-based paint is used to create lines and logos. The white paint used for the ice surface comes in 40-pound bags of powder that have to be mixed with water. The blue, black, red and yellow paints used for the lines and logos come in pre-mixed containers.

Now that you know about ice rinks and ice-resurfacing machines, you'll never look at them the same again. On a hot summer day when you go to the arena, you'll understand why the building is so cool and how the ice stays frozen!

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