When it slowly gets dark, the engines are started. With snow groomers, they freshly prepare all the slopes night after night. In good weather, the men are on the road from 5pm and ski every meter of slope until well after midnight.
On a well-attended slope, snow sports enthusiasts move the snow from the center of the slope to the outside and downhill every day. Without the daily preparation, the slopes would be brown and unusable within days, even in good snow conditions.
The blade pushes the snow back to the center of the slope and uphill. The caterpillars press the snow into a compact blanket. At the rear of the snow groomer, the tiller ensures loose snow on the surface. It reduces snow and ice so finely that the snow behind it is loose and powdery, as if it had just fallen from the sky.
The finishing touch to the perfect slope is provided by the finisher. The thick rubber mat provides the typical groove pattern in the snow. This is far more than simply a visible feature for slopes. The grooves increase the surface area of the piste. The larger the surface, the better for the sintering process, which now begins and takes a long time. Ideally eight hours before the first enthusiastic snow sports enthusiasts take possession of the virgin surfaces.
During sintering, the individual snow grains bond together without melting. The closer the temperature is to zero, the better this process works. Over time, the interconnected snow grains form a stable and solid base without becoming icy.
This creates a compact slope with good grip
In the past, the snow groomers also ran during the day. There are two reasons why they are no longer seen during the day.
First, snow groomers are by their nature hard, angular objects that can also still move. Soft, fast skiers and hard moving objects do not get along well on the same slope – if they came into close contact, the result would always be very unpleasant.
Secondly, the slope needs a lot of time after preparation to become compact at all. Directly behind the finisher, the fresh slope is soft and would look worse within a very short time than in front of the groomer.
Nature has the last word
New snow is always good, except at night. When it snows at night, the pistons, who want to do a good job, are left with a choice between two not really satisfying options.
If they ski in the evening, the slope has enough time to sinter and become firm, but in the morning it will be covered by fresh snow, which will be distributed on the slope quite chaotically within a short time and will not make the most beautiful slope picture.
However, if the snow is not prepared until the morning (usually from 3:00 a.m. onwards), the slope will not have time to become firm, depending on the temperature. The result is unsatisfactory for the night workers in any case.
In the end, one has to admit that even in the 21st century, skiing is – fortunately – a natural experience that cannot be controlled in all details by man.
Fresh snow on cross-country ski trails: If there has been more than 10 cm of fresh snow, it may not be possible to groom classic trails because the snow is too soft for the track.
Put on a leash
Some snow groomers have a superstructure with a crane-like structure – the winch. This is coupled to the engine. The wire rope can be up to 1,200 meters long. Attached to a fixed anchor point, the steel cable can be unwound and retrieved in a controlled manner. Although the winch’s power is not sufficient to pull the heavy vehicle up the slope, it does support the snow groomer. As a result, the tracks are less likely to lose their grip on the ground. After all, spinning is pretty bad on the slope. The heavy machines would dig through the snow cover in a flash and leave ugly holes.
But the long steel cables are not entirely harmless. Especially for nocturnal ski freaks, they can become a life-threatening threat. When the snow groomers switch from one side of the slope to the other, the finger-thick rope initially gets stuck in the snow. Only when it is pulled does it then spring from one side of the slope to the other. Anyone standing there would have bad cards. Therefore, the official slope opening times (respectively the last slope control) are really meant seriously and should be respected.