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Resort Information

Snowmaking at Perisher Blue

Waking up to the hum of the snowmaking machines during the winter at Perisher Blue is a welcome sign that there will be fresh snow on the ground from the season’s start to finish.

Perisher Blue invests heavily in snowmaking to ensure guests are provided with the best possible conditions all winter. In 2008, $9.75 million has been spent (in addition to the $3.6 million investment in 2007) on improving and expanding the resort's snowmaking system. The 2008 upgrade will deliver a new sustainable water supply, an upgraded pump station and 34 new automated snow guns in addition to the resort's 154 existing snow guns.

Techno Alpin has supplied the latest in automated snowmaking technology that will be up to nine times more energy efficient than existing systems and will improve snow reliability and quality.

Perisher Blue’s snowmaking now covers 43.9 hectares (an additional 3.5 hectares in 2008) across the resort. 188 snow guns pump snow out across Front Valley, from Mid Station of the Forester Quad Express through Yabby Flat and Goats Gully to Front Valley (new in 2008) and Tube Town at Perisher: the base of the slopes, rope tow and Captain Cook J-bar at Smiggin Holes; Early Starter, Road Run/Boot Hill, Zali’s, Snowsports School, Road Run to Roller Coaster and Excelerator (including Upper Excelerator) runs at Blue Cow.

Extensive work over the summer months is also carried out to create terrain that requires less snow to produce a safe and acceptable cover of snow for skiing and boarding. Examples of this work include summer grooming of the slopes, such as the removal of rocks and the erection of snow fences to help build up snow that can then be spread across the resort to locations which need additional cover.

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Future plans to increase snowmaking at Perisher Blue

Perisher Blue plans to increase snowmaking coverage to 110 hectares, aiming to have all the trails linking the four ski areas covered from the season’s start to finish. All new snowmaking at Perisher Blue will be automated to ensure that all snowmaking opportunities are maximised and that the snowmaking operation is as efficient as it can be. Perisher Blue also plans to automate its existing snowmaking over time. The result - skiers and boarders will be able to ski to and from each of the four areas all season long!

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How does snowmaking work?

To understand snowmaking, it is first necessary to understand what exactly snow is!

What is snow?

By definition, snow is ’crystallized ice particles having the physical integrity and the strength to maintain their shape’. Normally created by Mother Nature, but when Mother Nature does not deliver and snow is needed for ski resorts, that's when the snowmakers step in to ensure visitors to the resort are able to enjoy on-snow activities.

Natural snow forms when water vapour in a cloud formation condenses into a raindrop. Given cold atmospheric conditions the raindrop freezes and forms an ice crystal with six tiny arms (called dendrites). This is the classic snowflake. On the other hand, man-made snow forms a compact six-sided structure more like an ice cube.

How does snowmaking make snow?

Simply put, snowmaking replicates nature by converting water into snow.

Snowmaking requires a significant level of infrastructure including water storages, pump stations compressors, pipes, electricity supply, hydrants and weather stations. Snowmaking machines (commonly referred to as ‘snow guns’), make snow by breaking water into small particles, cooling the water by causing the particles to move through cold air, nucleating (the creation of small ice crystals) the particles and distributing the resulting snow on the ground.

The efficiency of snowmaking is largely driven by weather conditions. Low temperature and low humidity increase snowmaking efficiency, so in Australia, snowmaking is practicable mainly during the early to middle part of the season (typically mid-May to mid-August).

Efficiency of snowmaking is enhanced by snowmaking additives, which are added to the stream of water to promote the nucleation of the snow. Scientific research both here and overseas shows the additives cause no environmental concern. The National Parks and Wildlife authorise additive use.

Water

Snowmaking ‘borrows’ water from the catchment and eventually returns it. The majority of the water used for Perisher Blue's snowmaking comes from a Snowy Hydro aqueduct. About 93% of the water used for the snowmaking is returned to the streams in the spring thaw starting in September. In may ways snowmaking stores water for the winter and returns it to the streams in the spring.

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What is required for snowmaking?

An extensive system of steel piping is required to supply the snowmaking operation with compressed air and high pressure water through separate pipes to the snowmaking hydrants on the slopes. A pumphouse at the end of the system produces the compressed air and has high pressure pumps to supply the water.

Perisher Blue has two plant rooms, one at Perisher’s Front Valley and one at the base of the Terminal Quad Chair at Blue Cow.

Front Valley

Front Valley has two large centrifugal compressors supplying a total of 340m3 of compressed air per minute. During the compression process a substantial amount of heat is produced and this hot compressed air is then cooled to a usable temperature by piping it through a cooling tower. From the cooling tower the air then passes through air dryers. The dryers remove moisture by passing air through cylinders containing desiccant pellets that separate the moisture from the air. This moisture is then drained off.

Water is supplied from a pumpstation at North Perisher that fills a storage tank adjacent to the Front Valley plant room. Both air and water are then fed into the dual underground reticulation system onto Front Valley.

Blue Cow

The Blue Cow plant room has two centrifugal compressors supplying 340m3 of compressed air and four screw compressors supplying 168m3 of compressed air, providing a total of 508m3 of compressed air per minute. As in the Front Valley plant room, the air is then cooled and dried.

Water for Blue Cow is pumped from a Snowy Hydro aqueduct near the bottom of the Ridge Chair.

Smiggin Holes

Smiggin Holes uses fan guns. A submersible pump in a submerged tank pumps water for use by the snow guns.

Compressors Water Pumps

Snow Guns

Perisher Blue uses two types of snow guns: air-water guns and fan guns.

Air-water guns use a jet of compressed air from a central compressor to break up a stream of water into fine particles and propel these into the atmosphere under conditions which causes them to freeze as particles of snow. Fan guns achieve a similar effect by passing a stream of water into an airflow produced by a fan.

While fans are slightly more energy-efficient than air-water guns, they produce snow in a broad dispersed band that’s difficult to direct, especially in windy conditions.

Air-water guns produce a more concentrated stream of snow, which can be more effectively directed along confined trails or accumulated in a large pile for distribution by grooming machines.

Both types of snow guns can be mounted on a tower to increase the amount of time (‘hang time’) the water droplets are in the air, which increases the amount of snow that can be produced.

Compressed Air/water gun Fan Gun

Snow Quality

The snowmaker determines snow quality. Snowmakers will make either wet, medium or dry snow depending on the condition of the ski slope and weather conditions. Adjustments of the snow guns, which are made every half to one hour throughout the night, allow optimum snow production for the prevailing weather conditions, including temperature, humidity, wind speed and direction.

While adjusting the snow gun, the snowmaker may make the quality of snow wetter or drier depending on what the ski slope needs. Increasing water flow to a gun will result in a wetter snow and alternatively, decreasing water flow will result in a drier snow.

Wet Snow

In making snow, the general objective is to make it wetter and denser than fresh, natural snow. Snowmakers try to make snow similar to three-day-old natural snow because it lasts longer, wears traffic better, resists wind scour, grooms more easily and is more energy-efficient to make. Wetter snow is more efficient than dry snow because more can be made with the same amount of equipment, the same energy and the same staff.

Medium Snow

Medium snow is made when a run has adequate snow depth. Fresh, medium quality snow is easier to ski on than wetter snow. If snowmaking continues after slope grooming has taken place, medium snow quality is made so as not to destroy the groomed surface.

Dry Snow

Dry snow is generally made just before the snowmaking operation finishes and leaves a lighter, powdery cover on the ski slope that we all love to ski and board on!

How snow quality is checked

Each gun is checked for snow quality in two ways:

  1. By grabbing a handful of snow and squeezing it; and
  2. By letting the snow from the gun fall onto the snowmaker’s jacket sleeve. (Some snowmakers prefer to use a plastic hand piece instead of clothing.)

  Hand Jacket Plastic
Wet No more than 1 - 2 drops of water. Will stick together and will be slightly translucent. Some will bounce off jacket, about 5 - 10 mm.
Some will stick to the jacket.
 Will stick to the plate and be slightly white when pushed together.
Medium No water drops.
Mainly white in colour.
Will stick together if crushed.
 Some will bounce off jacket, about 5 - 10 mm.
Some will stick to the jacket.
 Will stick to the plate and be mainly white when pushed together.
Dry No water drops.
Will be powdery.
Completely white in colour.
 Some will bounce 20 mm plus.
Some will fall off jacket
 May not stick to the plate and will be all white when pushed together. Probably fall off plate.
Snow deposited by the snow guns is groomed flat by the groomers to produce a skiable slope before opening each morning. On very cold nights (-10ºC or colder), it can be quite a job because of the amount of snow that can be produced.

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