Snowmaking and grooming
Thredbo's automated snowmaking systems mean our skiiers and boarders enjoy around 100 days of riding in the village each year
Snowmaking
Why do we need snowmaking?
Well to put it simply Mother Nature is fickle. It's hard to tell when she's going to deliver in the snow department, for how long and where. Add plenty of other weather factors that can affect the snow once it's fallen into the mix and great snow riding conditions are not always a guarantee. Therefore, to enjoy the maximum amount of riding days possible, the problem of unpredictable weather and unreliable snowfalls has to be overcome.
Snowmaking is one of the most important installations ever made in Thredbo. Before snowmaking was installed Thredbo would enjoy 19 days of top to bottom snow riding, but now on average skiers and boarder enjoy around 100 days of riding to the village.
Without it we would not have the consistent conditions we have now. It is also very important to keep on improving the system so Thredbo visitors can always have the best possible snow conditions, even in marginal natural snow seasons, like 2006.
So just to recap this is why we have snowmaking:
Making snow is intricate business - so let's make it as simple as possible:
It's a common misconception that man-made snow is "artificial". In fact man-made snow is more or less the same as natural snow. "Real" snow starts as water vapour in the atmosphere. As temperatures dip, the water vapour condenses into tiny drops, or if it's cold enough, as tiny ice crystals. When enough ice crystals collect together they become heavy enough to fall towards earth (we see the collected snow crystals as snow flakes). Then if it's still cold enough they fall all the way to the ground, where hopefully they settle and form a rideable base. If it's warm the crystals melt and become the dreaded four letters "R-word" – rain.
Once the snow on the hill loses its crystalline structure it becomes spherical and loses it's ability to lock together like building blocks. However adding machine made snow to the snow surface re-initiates the crystalline structure, bringing the cover back to life. Yee-ha!
That said trying to re-create what nature does using thousands of metres of altitude and an incredibly complex weather system is not easy…. though funnily enough snowmaking was discovered by accident.
A 50's revelation installed by the 80's generation
In the 1950's a Californian citrus farmer was spraying his crop with water to prevent frost damage. The following result wasn't so great for him but as it happened the temperature was so cold the spray turned to snow. Jump forward 3 decades to the 80's (the decade of all things artificial) and Thredbo decided to give this idea a go.
In the winter of 1984, Thredbo started a snowmaking pilot system at the bottom of the Supertrail next to Valley Terminal, making snow with just three snow guns. "The pilot system ran for three winters and it was very successful. In the summer of 1986/87 the first stage of the current system was installed, this included the Supertrail from top of Snowgums chairlift to the bottom, Sundowner from Bunnywalk station and the Lovers-Leap bypass to the bottom of Snowgums chairlift. At that time the system was able to pump 5400 litres per minute of water and 12,000 cm3 of air per minute. In the summer of 1987/88 the second stage was installed adding Friday Flat, High Noon Merritts and the lower parts of Funnelweb. At the same time the water pumping capacity increased to 7200 litres per minute and air to 30,000 m3 per hour. At that time it was the biggest system in the southern hemisphere and it was able to operate up to 80 guns at an average temperature of -4 producing approximately 180,000m3 of snow in 700 hours of snowmaking hours per winter."
Phew! That's a lot of information. That was for the history buffs courtesy of our Mountain Manager, Werner Siegenthaler.
OK, enough background info, how does it actually work?
The actual process of making snow is pretty basic; just inject a mist of water into the atmosphere when it's cold. As the fine mist travels through the cold air, the water freezes and accumulates as snow on the ground. To do that there are very large air compressors and water pumps and a 10 km underground pipe network with 400 hydrant outlets. Water is drawn from the Friday Flat lake and it is pumped up the mountain in an underground water pipe. At the same time air is pressurised and sent up the mountain in another underground pipeline. The air and water are mixed under pressure in the snow gun and blasted into the freezing air.
Got that? Now you're probably thinking this uses up a lot of water… and it does, but the snowmaking water is eventually returned to the "snowmaking pond" so it's really just recycling on a rather large scale.
Perfect snowmaking conditions… as elusive as the Abominable snowman
Fair enough, optimal snowmaking conditions may not be this rare, but you do have to make the most of them when they occur as plenty of factors are at play.
The first thing you need is cold temperatures, that's why most snowmaking is done at the start of the season when nights are crisp and cold. But it isn't just the temp that needs to be right; it's also the humidity. Although the temperature may read minus 6 degrees on the dry bulb thermometer, the level of moisture in the air affects how quickly the water droplets will freeze. So the temperature snowmakers go by is the wet bulb temperature, which is a calculation of the ambient temperature and humidity in the air. As soon as it hits minus 2.5 degrees wet bulb the system kicks in and snow is made.
Snowmakers will make either wet, medium or dry snow depending on the condition of the slope. Increasing water flow to the gun will result in wetter snow while decreasing the flow makes drier snow. The guns in Thredbo can make all types of snow from very wet to sugary dry. The snowmakers have a scale from one to ten in which one is wet and ten is dry. They normally make snow at around six, however at the beginning of the season they make the snow quite wet so that it sticks to the ground and does not get blown away, and as a result builds a good base.
Other factors like wind speed and direction, air pressure and the temperature of the water being used to make the snow can also have a huge impact on snowmaking. The tricky bit is that all these factors are in a state of flux and need to be constantly monitored to make the best snow possible.
In the time it takes a snowmaking team to get the guns fully operational and the settings right for the current weather, conditions can change or the window of perfect snowmaking weather may be over – which can be very frustrating!!
But never fear! That's were automation comes into it
Automation – a very slick operation that creates the best snow riding foundation
In the summer of 2005/06 Thredbo installed the first stage of the new automated snowmaking system - automating 140 guns across the resort.
The beauty of automated snowmaking is that it's remotely controlled so with the click of a mouse the guns can be turned on and off, allowing the team to take advantage of the small windows of optimal snowmaking conditions, plus the guns adjust automatically and quickly as the conditions change.
Another factor that makes the Thredbo system different from other resorts is its size. It's an extensive system with a large underground pipe network that can be easily added to and upgraded.
Then summer 2006/07 the mountain crew installed another 72 automated snow guns, that saw the snowmaking system now fully automated, however there will always be some manual snow guns left in certain areas of the mountain.
Come summer 07/08 snowmaking was extended further, this time to the World Cup run that runs parallel to the mighty Supertrail. This enhancement will also see improved coverage of the run-out of Little Beauty and True Blue.
The three stage automation process has seen close to $6million being spent and the results of this upgrade are staggering. Thredbo's snowmaking system produced:
EUREKA! Where do I find this white gold?
The areas in Thredbo covered by snowmaking are:
Why do we need snowmaking?
Well to put it simply Mother Nature is fickle. It's hard to tell when she's going to deliver in the snow department, for how long and where. Add plenty of other weather factors that can affect the snow once it's fallen into the mix and great snow riding conditions are not always a guarantee. Therefore, to enjoy the maximum amount of riding days possible, the problem of unpredictable weather and unreliable snowfalls has to be overcome.
Snowmaking is one of the most important installations ever made in Thredbo. Before snowmaking was installed Thredbo would enjoy 19 days of top to bottom snow riding, but now on average skiers and boarder enjoy around 100 days of riding to the village.
Without it we would not have the consistent conditions we have now. It is also very important to keep on improving the system so Thredbo visitors can always have the best possible snow conditions, even in marginal natural snow seasons, like 2006.
So just to recap this is why we have snowmaking:
- It provides snow early in the season to get skiing and snowboarding started
- It improves and maintains the quality of the slopes during the season by topping up natural snow in the areas that have poor cover, either because of general rider "wear and tear" or not enough natural snow depth
- It supplements natural snow in locations that are prone to melting later in the season ensuring seasonal length and viability
- To have the best possible skiing product here in Thredbo for our guests.
Making snow is intricate business - so let's make it as simple as possible:
It's a common misconception that man-made snow is "artificial". In fact man-made snow is more or less the same as natural snow. "Real" snow starts as water vapour in the atmosphere. As temperatures dip, the water vapour condenses into tiny drops, or if it's cold enough, as tiny ice crystals. When enough ice crystals collect together they become heavy enough to fall towards earth (we see the collected snow crystals as snow flakes). Then if it's still cold enough they fall all the way to the ground, where hopefully they settle and form a rideable base. If it's warm the crystals melt and become the dreaded four letters "R-word" – rain.
Once the snow on the hill loses its crystalline structure it becomes spherical and loses it's ability to lock together like building blocks. However adding machine made snow to the snow surface re-initiates the crystalline structure, bringing the cover back to life. Yee-ha!
That said trying to re-create what nature does using thousands of metres of altitude and an incredibly complex weather system is not easy…. though funnily enough snowmaking was discovered by accident.
A 50's revelation installed by the 80's generation
In the 1950's a Californian citrus farmer was spraying his crop with water to prevent frost damage. The following result wasn't so great for him but as it happened the temperature was so cold the spray turned to snow. Jump forward 3 decades to the 80's (the decade of all things artificial) and Thredbo decided to give this idea a go.
In the winter of 1984, Thredbo started a snowmaking pilot system at the bottom of the Supertrail next to Valley Terminal, making snow with just three snow guns. "The pilot system ran for three winters and it was very successful. In the summer of 1986/87 the first stage of the current system was installed, this included the Supertrail from top of Snowgums chairlift to the bottom, Sundowner from Bunnywalk station and the Lovers-Leap bypass to the bottom of Snowgums chairlift. At that time the system was able to pump 5400 litres per minute of water and 12,000 cm3 of air per minute. In the summer of 1987/88 the second stage was installed adding Friday Flat, High Noon Merritts and the lower parts of Funnelweb. At the same time the water pumping capacity increased to 7200 litres per minute and air to 30,000 m3 per hour. At that time it was the biggest system in the southern hemisphere and it was able to operate up to 80 guns at an average temperature of -4 producing approximately 180,000m3 of snow in 700 hours of snowmaking hours per winter."
Phew! That's a lot of information. That was for the history buffs courtesy of our Mountain Manager, Werner Siegenthaler.
OK, enough background info, how does it actually work?
The actual process of making snow is pretty basic; just inject a mist of water into the atmosphere when it's cold. As the fine mist travels through the cold air, the water freezes and accumulates as snow on the ground. To do that there are very large air compressors and water pumps and a 10 km underground pipe network with 400 hydrant outlets. Water is drawn from the Friday Flat lake and it is pumped up the mountain in an underground water pipe. At the same time air is pressurised and sent up the mountain in another underground pipeline. The air and water are mixed under pressure in the snow gun and blasted into the freezing air.
Got that? Now you're probably thinking this uses up a lot of water… and it does, but the snowmaking water is eventually returned to the "snowmaking pond" so it's really just recycling on a rather large scale.
Perfect snowmaking conditions… as elusive as the Abominable snowman
Fair enough, optimal snowmaking conditions may not be this rare, but you do have to make the most of them when they occur as plenty of factors are at play.
The first thing you need is cold temperatures, that's why most snowmaking is done at the start of the season when nights are crisp and cold. But it isn't just the temp that needs to be right; it's also the humidity. Although the temperature may read minus 6 degrees on the dry bulb thermometer, the level of moisture in the air affects how quickly the water droplets will freeze. So the temperature snowmakers go by is the wet bulb temperature, which is a calculation of the ambient temperature and humidity in the air. As soon as it hits minus 2.5 degrees wet bulb the system kicks in and snow is made.
Snowmakers will make either wet, medium or dry snow depending on the condition of the slope. Increasing water flow to the gun will result in wetter snow while decreasing the flow makes drier snow. The guns in Thredbo can make all types of snow from very wet to sugary dry. The snowmakers have a scale from one to ten in which one is wet and ten is dry. They normally make snow at around six, however at the beginning of the season they make the snow quite wet so that it sticks to the ground and does not get blown away, and as a result builds a good base.
Other factors like wind speed and direction, air pressure and the temperature of the water being used to make the snow can also have a huge impact on snowmaking. The tricky bit is that all these factors are in a state of flux and need to be constantly monitored to make the best snow possible.
In the time it takes a snowmaking team to get the guns fully operational and the settings right for the current weather, conditions can change or the window of perfect snowmaking weather may be over – which can be very frustrating!!
But never fear! That's were automation comes into it
Automation – a very slick operation that creates the best snow riding foundation
In the summer of 2005/06 Thredbo installed the first stage of the new automated snowmaking system - automating 140 guns across the resort.
The beauty of automated snowmaking is that it's remotely controlled so with the click of a mouse the guns can be turned on and off, allowing the team to take advantage of the small windows of optimal snowmaking conditions, plus the guns adjust automatically and quickly as the conditions change.
Another factor that makes the Thredbo system different from other resorts is its size. It's an extensive system with a large underground pipe network that can be easily added to and upgraded.
Then summer 2006/07 the mountain crew installed another 72 automated snow guns, that saw the snowmaking system now fully automated, however there will always be some manual snow guns left in certain areas of the mountain.
Come summer 07/08 snowmaking was extended further, this time to the World Cup run that runs parallel to the mighty Supertrail. This enhancement will also see improved coverage of the run-out of Little Beauty and True Blue.
The three stage automation process has seen close to $6million being spent and the results of this upgrade are staggering. Thredbo's snowmaking system produced:
- 2005 Pre-automated (before the upgrade) - 180,000 m3
- 2006 Stage 1 automation - 330,000 m3
- 2007 Stage 2 automation - 430,000 m3
- 2008 Stage 3 automation - anticipated production 480,000 - 500,000 m3
EUREKA! Where do I find this white gold?
The areas in Thredbo covered by snowmaking are:
- Supertrail to the village (from the top of Snowgums Chair downwards),
- High Noon
- the Cruiser area's Walkabout and Ballroom,
- Sundowner
- Lovers Leap bypass
- Friday Flat
- under Snowgums chair to the village via Milk Run
- Rossi Racecourse
- Both sides of High Noon
- Friday Flat
- World Cup
- Lower True Blue
- In total this is an area of approximately 67 hectares, covering 25% of the skiable terrain.
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