More Classes Today…A Tribute to the Snowmakers.
We pay a lot of homage to the snowmaker of our region. After all without them we might ski ten or fifteen days a season. Okay maybe more, maybe less…but the point is without the advancements in snowmaking technology and the invaluable people behind the scenes…we would certainly not ski approximately 130+/- days a season. Without snowmaking and the people who put in countless hours in the middle of the night, in some of the most bitter conditions imaginable, you would not have the groomed, perfect cordoroy-surface in which we love to play on.
These facts are not lost on those of us who have wanted to make some turns at our favorite resorts thus far this season. We’ve fielded a lot of emails from you guys wanting to know the scoop about snowmaking. Common questions are:
"We hear it’s artificial, does that mean it’s like foam?"
"Why doesn’t all the snow melt when temperatures hit 50 degrees or so?"
"How do snow making machines work?"
…and there are others.
Thankfully snowmaking crews all across the southeast have now cranked up their equipment and are laying it down for what now looks to be a wonderful Holiday season of sking and riding. We were at Snowshoe Resort this past weekend and although we had some moderate-to-heavy snowfall all day on Saturday (December 11, 2004) there would not have been enough snow to handle the skier traffic on Sunday if it were not for the fact that the mountain ops people began firing the snowguns all over mountain long before visitors awoke, showered, had breakfast and hit the slopes. One of our On-Snow Reporters, Austin Beeghly, from Orlando, spent one late night at Cataloochee a couple of weeks ago watching Sammy and his talented crew go up and down the mountain countless times readying and adjusting equipment for over six hours. Austin left without seeing the snowguns going. It turns out that just a short time later these devoted snowmaking people were able to crank them up and pour the snow to the slopes.
What is behind snowmaking…We thought that we’d answer some of your questions and provide some interesting information about how it works…and the people behind the scenes. Now that winter has hit and temperatures have been COLD, we’ll be focusing on THE SKIING AND RIDING. However today we want to focus on the people behind the scenes that just don’t get enough credit. Today it is all about snowmaking.
A Little HistoryIn the early 1900’s, the sport of snow skiing skyrocketed in popularity. As more and more people discovered the sport and made it a yearly getaway, ski slopes became profitable businesses. (Note: Not all resorts were that profitable from the start. Many of our region’s resorts struggled to stay afloat and many didn’t.) However, the most important factor in that success was the weather. If it didn’t snow, or didn’t snow enough, they had to close everything down until the weather decided to cooperate. In most areas, the ski season was limited to a month or so. Without snowmaking capabilities NONE of our Southeastern resorts would have ever been opened in the first place.
The solution was to figure out a way to make snow when you needed it, in case nature failed to provide. The result was an invention called the snow gun. This device proved useful even when natural snow was plentiful because it gave resort owners greater control over the consistency of the top layer of snow, allowing them to create better skiing conditions. These days, snow-making machines are standard equipment in the vast majority of ski resorts around the world. They have made it possible for many resorts to stay open four months or more a year, and there are even a few indoor slopes that stay open year-round!
Is Manmade or Machine Made Snow "Artificial"? That is a common question. Technically it’s actually the same stuff that falls from the sky. It is simply created by a machine rather than Mother Nature.
Natural snow comes from water vapor in the atmosphere. Clouds form when the water vapor (water in gas form) in the atmosphere cools to the point that it condenses — that is, changes from a gas into a liquid or solid. The droplets in a cloud are so light that the air in the atmosphere keeps them aloft. If the droplets get too heavy, they fall in the form of precipitation. If it is cold enough, this water vapor doesn’t condense as liquid water droplets, but instead as tiny ice crystals. In most parts of the world, rain generally starts out as snow but melts as it falls through the atmosphere (it is very cold at cloud level, even in the summertime).
Oddly enough, water doesn’t automatically freeze at "freezing temperature" — 32 degrees Fahrenheit / 0 degrees Celsius. You have to cool pure water to a much lower temperature (as low as -40 F / -40 C) for it to lose enough heat energy to change form. Usually, however, water in a cloud does freeze around 32 F / 0 C because of the work of nucleators, tiny bits of naturally-occurring material that help water molecules coallesce. The nucleators attract water molecules, which reduces their energy to the point that they form ice crystals. The nucleators in snow crystals are just dirt bits, bacteria and other material floating around in the atmosphere. Water condenses onto the nucleator, which becomes the nucleus — the center — of the snow crystal.
Oh…that got too deep…so for the rest of this story we’re going to stay on the basics.
As the snow crystal moves around the cloud, more water particles condense onto it and freeze into crystals. The collection of individual crystals forms a snow flake. As the snow flake grows heavier, it falls toward the earth. If it is cold enough the whole way down, the flake will still be frozen when it reaches the surface.
So how is Manmade Snow created?Using nature as a guide, we find that the main things you need to manufacture snow are water and cool temperatures. It helps the process along if you mix in a nucleator of some sort into the water supply. The water will already contain lots of stuff that can act as nucleators, but increasing the count is a good idea because it ensures that more water droplets will freeze before they reach the ground. One of the most widely used nucleators is a natural protein called Snowmax that is especially good at attracting water molecules.
The traditional type of snow gun produces water droplets by combining cooled water and compressed air. On a ski slope, you’ll notice that these guns are attached to two different hoses that run to air and water hydrant stations, respectively. The hydrants are hooked up to two different lines which run under the snow or even underground. One pumps in water from a lake, pond or reservoir and the other pumps in high-pressure air from an air compressor.
The compressed air serves three major functions:
1. It atomizes the water — that is, disrupts the stream so that water splits into many tiny droplets.
2. It blows the water droplets into the air.
3. It helps cool the water droplets as they fly into the air.
The fact is When air is compressed, the different air particles are pushed tightly together, which means they don’t move around as much. When the air is released, the particles spread out and move more freely. This means the particles are using more energy, absorbing heat from the area around them and thus cooling the air around the water droplets.
Snowmaking inventors continue to search for easier ways to atomize the water into a fine mist, without using a huge amount of power to do so. You can’t imagine the cost of running all of those compressors!
Then came the airless snow gunGo to where you keep all of the cleaning fluids in your home and pull out a bottle of Windex. Turn the little adapter on the end to where it sprays liquid out, rather than a stream of fluid. That’s kind of how an airless snowgun works. Airless snow guns use simple nozzles to atomize the water into the finest mist possible. That mist (water droplets in their smallest form) is then blown up into the sky by a powerful fan and as that mist freezes in the cold air…voila…we get snow. The huge benefit of these kinds of guns…is that you don’t need all of that expensive-to-create compressed air.
There are some snowguns that actually atomize the water WITH high speed fans. We have marveled as resorts seem to be able to make snow these days in marginal weather/temperature conditions. Believe it or not there are now actually snow guns that use special cooling devices built into the machine that speed up the freezing process when natural conditions are not quite up to doing the job.
So let’s review for a sec –To make snow we want to get water down to it’s smallest level (atomize or mist) and we also want to get it up into the air so that the cold air can transform it into snow. That’s JUST the beginning…really. To give the water enough time to freeze before it falls to the ground, many resorts use snow gun towers. These are simply sturdy poles that elevate the snow gun above the slope. Another advantage of this set-up is that the snow guns can be less disruptive to skiers. And the snow falls from above, as it would naturally…kind of!
Now if you’re out there thinking, "Well this is cool…I’m going to make enough snow in my own back yard, strap on my skis and the heck with the expensive lift tickets," …not so fast! If you think snowmaking is all there is to it, think again. We happened to be over at Ski Beech installing a new camera on the second day of their snowmaking efforts just last week. Their talented snowmaking crews had REALLY poured on the snow and the hill was covered in a deep coating of white. It LOOKED impressive…and it could have been skied on that day. However, we walked out for some photo ops and while the surface WAS beautiful…and could have been skied on…it was quite inconsistent with a hard-to-walk on surface. That’s where the snow GROOMERS come into play.
At most resorts, workers will accumulate a big pile of manmade snow and then disperse it along the trail with snow-grooming equipment. Snow groomers are just tractors with very wide tracks that spread the snow around and compact it to make it dry and powdery. For ski resorts, regular grooming is an essential part of the snow-making process.
So you think YOU are ready to make snow? Oh NO grasshopper. Until you can snatch the snow crystal from my hand, you shall be resigned to pulling hoses and equipment around. Here’s where only the most experienced of SNOWMAKERS come in. While snowguns and snowmaking machine do the deed…it’s the snowmakers – real, living, breathing, hard-working souls do the hard stuff.
Ski resorts depend on the expertise of experienced snow machine operators, commonly called snow-makers. These guys have to figure out when conditions are right for the guns to be turned on and if you’re reading this thinking, "Duh, just watch the thermometer and when it hits 32 degrees turn the dang guns on"….quit thinking out there class and just read on.
It turns out they need a lot more information than they can get from an ordinary thermometer. Standard thermometers measure the dry bulb temperature of the atmosphere; but the most important factor for snow conditions is the wet bulb temperature.
The wet bulb temperature is a function of the dry bulb temperature and the relative humidity, the amount of water vapor in the air. Liquid or solid water cools itself by evaporating some water as water vapor. This releases heat, and so lowers the energy level in the water. When there is more water vapor in the atmosphere, water or snow can’t evaporate as much because the air is already saturated with water to a high degree. Consequently, water cools more slowly when the humidity is high, and more quickly when the humidity is low. In the words of Brittany Spears, "Oops I did it again." I went too scientific.
The bottom line is that HUMIDITY is a very important factor in determining snow conditions. If the humidity level is low enough, you can actually get snow even when the dry bulb temperature is several degrees above freezing. If the relative humidity is 100 percent, then the wet bulb temperature and the dry bulb temperature will be exactly the same. But even if both are at the freezing temperature, you might get rain instead of snow because the air saturation slows the cooling process down so much.
So, actually making snow is a bit more complex than we all think. snow-makers must carefully balance the levels of water and air to get the desired results. There are all different kinds of snow. The main difference between snow types is how much water a certain volume of snow holds. Snow-makers often talk about dry snow and wet snow. Dry snow has a relatively low amount of water, so it is very light and powdery. This type of snow is excellent for skiing because skis glide over it easily without getting stuck in wet slush.
Snowmakers change up the KIND of snow they make. While dry snow is great for skiing…wet snow plays an important role on ski slopes. Resort owners use this denser wet snow to build up the snow level on well-travelled trails. Many resorts build up the snow depth this way once or twice a year, and then regularly coat the trails with a layer of dry snow throughout the winter.
Snow-makers have to adjust the proportions of water and air in their snow guns to get the perfect snow consistency for the outdoor weather conditions. Just in case this didn’t sound tough enough, bear in mind that the weather conditions vary considerably from point to point on a ski slope! Snowmakers literally have to go up and down a mountain numerous times to adjust each machine accordingly.
There are now new innovations that are making it easier to handle these adjustments. Wintergreen Resort installed a system that allows them to now control their snow guns with a central computer system that is hooked up to weather-reading stations all over the slope. The computers make a determination of the best snow-and-air mix based on the temperature and relative humidity at a given point. These systems do not always get the mix right, of course, but they are a great snow-making aid.
The Human Element Imagine getting out in the middle of summer and walking up and down these steep inclines that are common to all of our resorts and while you’re enjoying your walk…lug some equipment around. Take some tools with you and mess around in the water all day and all night for a few months. You’re going to be one tired character with dishpan hands that you can only imagine. Oh and boy will that body be aching!
Now throw in that MOST of the time you’re doing this in the dark. Carry a flashlight because it REALLY gets dark out. NOW, fast forward to the harsh cold temperatures of winter in the mountains. Often temperatures are in the sub zero to ten degree range, with blustery winds. Now the snowguns are firing all around you carrying the heavenly snow mist that you worked so hard to make…all over your body.
I think you’re getting the picture. This stuff is HARD WORK and the people that do this to make our experience on the snow should be appreciated. However, more often than not, these guys don’t even get a thank you. So the next time you’re out on the snow and see a snowmaker over on the side doing his thing…cruise by, stop and give him a hug. Okay, that’s not the best idea because after all that hard work they’re pretty grumpy. However, you could stop, keep your distance and YELL THANK YOU!
In another story that we have planned, we’ll look into THE COST of making snow.
Until then THINK SNOW…and THANK YOUR SNOWMAKER!
More Classes Today…A Tribute to the Snowmakers.