How do Big Bear Mountain Resorts provide world-class skiing and snowboarding when Mother Nature is being a bit, well…difficult? Snowmaking. Here is some interesting information and facts about our local resort’s snowmaking systems. Courtesy of SnowSummit.com

Snowmaking Basics

Man-made snow is real snow (not “artificial”) made by “guns” spraying atomized water particles under high pressure into the cold dry atmosphere, which freeze into snow particles before they hit the ground. The colder and drier the air, the more water can be put through the gun. No additive or chemical is put in the water.  The only difference between natural and man-made snow is that the latter falls as small round pellets due to the air turbulence, while natural usually comes in the form of small to large flakes.  However, in windy conditions even natural snow will be blown into small pellets or even marble-sized balls called “grapple”.  Natural snow can be very wet or dry, depending on its water content, the same as with man-made.  After two or three days on the ski runs, natural snow becomes indistinguishable from man-made as both are subject to skier traffic, grooming, and the freeze/thaw cycle.

Buried Pipelines

Many miles of buried steel air and water pipe lines, from 2 inches to 2 feet in diameter, deliver the high pressure water and air throughout the mountain. Attached to the main lines are hydrants placed on the sides of runs, every 50 to 150 feet or so. Each resort has about 500 hydrants lining its runs. The “air” guns are attached to the hydrants by air and water hoses and the “fan” guns by water hoses and electrical lines.  The guns are placed exactly where the snow is to be made and when enough snow is made at one location, they are moved to another.

The Guns

We use two types of snowmaking guns. One uses compressed air mixed with water at the gun (which is really just a tube with a small nozzle at the end) to atomize the water into particles small enough to freeze quickly. The other “airless” type uses an electric fan in a 5 foot long by 2 ½ foot wide tube that pushes an air stream into which small particles of water are sprayed by dozens of tiny nozzles on the rim of the tube.  (Fan guns aren’t completely “airless”; there is a small on-board compressor that helps to atomize the water at the nozzles.) If we just sprayed water straight out from a hose, without atomizing the water, it would be like rain water droplets that are too big to freeze before they hit the ground, which would then freeze on the ground as ordinary ice.

The colder and drier the air, the more snow can be made at each gun since more water can be introduced into the outside air mass because it can freeze faster. In 2006, about 70 “airless” fan guns and about 80 “air” guns can operate at one time at Snow Summit alone.  Bear Mountain operates about 45 fans and 90 air guns respectively.  (We actually have several types of air guns, but they all function basically the same way.) A number of both types of guns are mounted on towers, from 6 to 20 feet high.  While they can’t be moved to put the snow exactly where desired, they produce more snow than guns close to the surface because there is more “hang time” for the water particles to freeze before they hit the ground.

Tremendous Snow Production

Each gun can produce an amazing amount of snow in good conditions (5% to 20% humidity and 10° to 20° F), much faster than Mother Nature.  A compressed air gun can convert about 70 gallons per minute (gpm) into snow while a fan gun can convert up to 200 gpm in those conditions. (Consider that a garden hose puts out about 3 to 5 gpm.) So, in ideal conditions, each resort’s system can convert about 5,000 to 6,000 gallons of water per minute into snow! That’s a good sized stream flow that could fill a backyard pool in about 5 minutes! If a gun is left unmoved in those conditions, it can make several feet in front of it in a few hours, sometimes burying itself.

We can’t put 5,000 gallons per minute worth of snow on just one run at a time due to the limitations of pipe sizes and number of hydrants, so instead, we make snow on several runs at one time and might put an average of one foot of snow down on each. In normal snowmaking conditions we can open a run in about 48 hours of snowmaking over bare ground. At the start of the season, we typically open several runs and lifts after a couple of days and nights of snowmaking, and open still more soon after that.

Snowmaking Water

The practically unlimited water source for Big Bear Mountain Resort’s large scale snowmaking is Big Bear Lake. It’s pumped from the lake to the resorts and then up the mountains. Multi-million gallon reservoirs on the resorts store water for heavy production because the lines from the lake can’t flow enough water at those times. This lake water supply is the main reason Big Bear’s resorts can virtually guarantee skiing on most runs all winter long, even in the driest winter. Throughout the season, Summit and Bear each can produce at least twice the snow of any other local resort, which rely on limited amounts of on-site well water.

We have an annual allotment from the lake that we have never needed to exceed.  If used entirely, it would draw the lake level, when full, down only about 4 inches – and at least 50% of that runs back into the lake during the spring snowmelt!

Grooming

Grooming by snowcats pushing and tilling the man-made snow is an important element in providing good skiing. While the snowmaking guns are moved frequently, there typically will be piles left in front of each gun which must be graded into a smooth, relatively flat surface before operations. After a good period of snowmaking some of these snow mounds may be as big as a small bus and are called “whales” by the crew. After the new snow is spread evenly, the surface is gone over with a tiller on the back of the cat, which is a sort of grinder that pulverizes the top 3 to 6 inches of the snow to give it the ideal texture for skiing or boarding. Grooming is a real art to know when and how to push the snow around and condition it into a good grippy surface preferred by skiers and snowboarders. Fresh man-made snow is nearly always groomed into a consistently good surface prior to opening.

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