A few days ago, the Beijing Winter Olympics Yanqing Division
National Alpine Ski Center
About 800,000 square meters of snowmaking tasks
It is almost complete
The snowmaking thickness of the race track is about 1.5 meters
Snowmaking at the National Alpine Ski Center
Q: Where did all this snow come from?
Is it heaven and earth?
In fact, it started many years ago
Natural snowfall is no longer used in the Winter Olympics snow sports
Especially the snow on the slopes of many projects
It's all "ice-like snow" made by a specific process.
Alpine skiing competition Photo/Xinhua News Agency
Alpine skiing is known
"The jewel in the crown of the Winter Olympics"
And the manufacture of icy snow
It can be said that the cornerstone of casting this pearl
Because of its large hardness, it is not easy to be destroyed
Ice-like snow attracted a lot of attention during the competition
Well, the icy snow before "going to work"
What are the necessary processes and steps that need to be gone through
Xiaobian takes you to reveal the secret together~
STEP 1 Snowmaking
Snowmaking is particularly important as the first part of the track production. Artificial snowmaking is the use of snowmakers to mix water and high-pressure air to create snowflakes under suitable conditions.
Wu Longxing, engineering construction consultant of Yanqing Competition Area of Beijing 2022 Winter Olympic Games, introduced:
"Snowmaking machine snowmaking is the same principle as a small amount of frost when the core of a bicycle valve is rapidly deflated, and when the high-pressure gas and the small droplets of water mixed in it are sprayed into the cold outside air, they will solidify into tiny ice crystals."
In addition, the role played by snowmakers cannot be ignored. Snowmakers need to consider meteorological factors such as temperature, humidity, wind speed, wind direction, etc., place the position of the snowmaker according to the wind direction and wind speed, control the compression and mixing ratio of water and air, and inject water into the water pipe of the snowmaker.
Snow machines are making snow
Under the action of high-pressure air, the water will be divided into tiny particles through a special nozzle and then sprayed into the cold external air (the farther the spray distance, the better the snow quality), and these small water droplets will solidify into ice crystals before falling to the ground, which is what people see artificial snowflakes.
STEP 2 Water injection
Different from the Volkswagen snow field, the manufacture of the ice-like snow track requires the addition of water injection steps after the snowmaker makes snow, so that the surface of the snow track remains in a crystalline state similar to the ice surface.
Icy snow with water-filled contours clearly visible
The density of artificial snow used in volkswagen ski resorts is 400 to 500 kg/m3, while the density of icy snow needs to reach more than 590 kg/m3, so as to ensure that the track has a certain strength and sufficient elasticity, so that the snow quality of the skiers who start before and after is consistent, and thus ensure the fairness of the race.
Ice-like snow measures water injection
Let's start with a video
How exactly does the water injection step work?
Before the competition, the staff will make predictions according to the weather forecast issued by the meteorological department, adjust the water injection plan according to the characteristics of the climate, and then, like ploughing the ground, turn the snow under the slope up to form a loose snow layer of about 40 cm, and use the cannon to inject water below the snow surface to increase the water content of the snow.
Crews are filling the track with water
During the process of filling the water, the staff will also perform a series of operations such as repeatedly turning the wet snow until it is evenly beaten.
STEP 3 Snow pressure
Compared with the smooth snow surface, the "noodle snow" pressed by the snow compressor makes the snowboard eat the snow deeper, which better responds to the power of the skier's body.
The snow plow depth, the number of snow ploughs and the speed of the snow plough, as well as the driver's operating level, are all important factors affecting the quality of the snow pressurized snow. The staff needs to check the water injection according to the temperature on site and at night, and then press the snow to form a snow surface.
Snow grooming
In view of the problem of different heights and uneven slopes, snow presses can sweep the snow surface to play a role in uniform snow volume, and can also break snow masses and thin ice on the snow surface, so as to make the snow softer and make the snow more flat.
STEP 4 detection
Since there are so many requirements for making an ice-like snow track, how to judge whether the snow quality is qualified?
In the past, people mostly used the method of manual judgment, finding some experienced referees to step on the track and subjectively judge the construction quality of the ice-like snow track.
Today, the Snow Support Research Team of the Winter Olympics has cooperated in the development of ice and snow particle size measuring instrument and ice and snow hardness measuring instrument.
Particle size measuring instrument
Hardness measuring instrument
The track state is more accurately described from the aspects of particle size, hardness and density, which provides a reference for the transparency of the production standard of the ice-like snow track in the post-Olympic era.
Snowmaking, water injection, snow pressurization, testing
Go through these processes
A qualified icy snow track
Paved out
Did you get it?