What kind of water is used to pour ice for competitions? How thick is it? How is it removed afterwards?
Many such questions may arise when watching elegant figure skating competitions or dynamic and hard hockey games. Many ice sports events are held in the same arenas that also host basketball games, concerts and other events. How does that work?
Well, it depends on the arena and its capabilities, but there are some things that we know.
For example, Žalgiris Arena in Kaunas, Lithuania, is mostly famous for basketball games and concerts, but skating events are also held there. This capability was planned when the arena was being built – the concrete under the floor has a cooling system. The European Figure Skating Championships were held at Žalgiris Arena in January 2024. That’s when we learned about the ice.
Ice in an arena is poured layer by layer – water is poured, it freezes, then more water is added on top until the specified thickness is reached. For Žalgiris Arena it took a couple of days. The air temperature in the ice area is maintained at approximately +5°C, but the ice is cooled from below to avoid melting. The spectators sit at much cosier +18°C.
Do they use special water? Nope. Just regular tap water. The ice for the 2024 European Figure Skating Championships was just over 4 cm thick. Maintaining a thicker block of ice would require more energy. 4 cm is plenty strong and it doesn’t matter – under it is concrete, not water. Some arenas pour thicker ice and some – half as thick, especially if it’s a short one day event.
The top layer of the ice needs to be maintained and cleaned. It’s a good thing that in the 1940s Californian Frank Zamboni invented a self-propelled ice-cleaning machine now best known by his name. Zamboni machine scrapes off the top layer of the ice, creating smooth even surface, and coats the ice with a thin layer of warm water. That water immediately freezes. Some deeper holes need to be filled by hand.
Removing the ice is simple, but it depends how quickly it needs to be gone. If they can scrape it off and then allow the remaining bits to melt or be swept away – that’s a good way to do it. But sometimes the ice is broken in large chunks and is thrown outside – that’s what Žalgiris Arena did.
