By: Brendan Lenko, P.E. Ice in many different ways can effect a skater's performance. Whether its controlling a puck in hockey, landing a jump in figure skating, or holding a corner in speed skating, the quality of the ice is important for skaters to perform their best. Just as there are many different ways to sharpen a skate blade, there are many different qualities of ice. Most are aware that figure skaters prefer warmer, softer ice at a temperature of 25 F - 26 F and hockey players prefer harder ice at 22 F or so. But, there are other qualities such as brittleness or chippiness, friction, smoothness, and snow quality which can all either help or hinder a skater's performance. Imagine a little tiny ice chip, for example, stuck to the ice because of the humidity in the ice area. Although a figure skater may never even acknowledge it, a hockey player would certainly know if a pass hit this chip causing the puck to suddenly jump two feet over his stick. This would be even worse if he were on a break away. That ice chip was likely caused by brittle (or chippy) ice, the type that either froze too quickly or was maintained too cold. When either of these happens, the ice forms into long grains of high stress which are just waiting to break. Then, because ice will usually fracture along its grain boundaries (like wood for example) longer the ice grain formations cause larger the ice chips. When ice chips break away, they usually leave deep cuts or ruts in the ice. Although a puck can glide over these ruts easily, a skate blade in such a rut can slow a player down or even cause injury. Now, because ice is actually a high temperature material like many metals, brittle ice can be treated just as brittle metals are tempered to become tougher and more ductile. In both cases, raising the material's temperature closer to its melting point for a period of time will relax the built up stresses and temper it to prevent the brittleness. Raising ice temperature up to 26 F or 28 F for 6 or more hours at a time will effectively temper the ice to toughen it and help prevent the chippiness. Even if the temperature is later brought back down to 22 F for hockey, it will still be tougher and more resistant to ice chippiness. Snow too, if it is heavy can stick to the ice and prevent it from being smooth. This again effecting puck movement in hockey. In humid or damp rinks, the snow can act almost like a sponge and become very heavy and wet. Then, if the ice is really cold, it can refreeze to the ice causing a very rough surface for the puck to glide on. Maintaining a relative humidity of 40-50% with a space temperature of 45-55 F will certainly help prevent the wet snow. In fact, because a puck will glide more easily through light, dry snow, it even makes sense to dry out the rink further to 30% temporarily during the important events. The friction of the ice is also important to skater's performance. Mechanical friction, for example, occurs when a skate cuts in and deforms the ice. Where skates cut deeper into soft ice, it will slow down the skater because of the added force required to cut through the ice. Keeping the ice hard certainly reduces this mechanical friction and allows all skaters to skate with less effort. That is, when the ice is hard, skates will not penetrate as deeply into it and therefore they will not have to cut through as much ice. Sliding friction, on the other hand is more important to speed skaters because even the smallest difference in speed is critical. This type of friction is basically the surface to surface friction that occurs between any two objects in contact. Although sliding friction is actually reduced with warmer ice temperatures (up to 28 F), it is not normally advisable to warm up ice because of the increase in mechanical friction. The best way to improve sliding friction is to remove the minerals in the water which is used for ice making. The amount of sliding friction is actually reduced with the mineral content in the water. Water purification systems that purify the water for ice making can drastically reduce the friction and actually speed up the ice. Such pure water also makes the ice sheet denser and harder resulting in less mechanical friction as well. The tools to achieve these good ice conditions are readily available on the market today. Ice temperature control systems that control the ice surface temperature with an infrared sensor can be used to set ice temperatures higher for tempering and removing brittleness. They can also be used to accurately control ice at different temperatures for different activities such as 22 F for hockey, 25 for figure skating etc. Water purification systems for ice making are also available and can help provide some of the qualities that make good ice. When properly controlled, demineralized water has been known to provide the fastest, hardest and toughest ice. It also typically results in less snow build up because the skates do not cut as deep into the ice. As such, there can be compound improvements with the use of a flood water treatment system. More importantly, these tools alone are not the only ingredient to making good ice. These is no substitute for a knowledgeable and experienced ice maker who understands how the ice performs under different conditions and can make the necessary adjustments to keep ice in good standing. Only such an individual will be able to use these tools to their fullest and provide the desired results on the rink reliably and consistently. About the Author: Brendan Lenko, P.E. is a professional engineer and president of Energy Ice. Over his career, he has designed many infrared ice temperature control and monitoring systems as well as demineralized flood water treatment systems for ice rinks including facilities in the NHL, Olympic, Curling Championship and others. If you have questions relating to infrared ice temperature control, water treatment or just ice quality & engineering in ice rinks in general, you can reach him in Canada at (905) 632-8840. |
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