Piste preparation by night

How to prepare perfect slopes

Night shift on the slopes

When night falls on Lenk, the motors start. Night after night, eleven snow groomers prepare and freshen up the slopes. If the weather is good, the men set out at 5 p.m. and groom every slope until well past midnight.

Daily grooming

On the more popular ski slopes, winter enthusiasts push the snow from the middle of the slopes outwards and downhill daily.

Within the day, even with good snow conditions, the slopes would become unusable and brown without daily grooming. Thirty years ago, water was used to simply ice over the slopes so that at least the lowest layer survived the season. Nowadays, such slopes would not make the final cut.

The snow plow blade pushes the drifted snow once more up and into the middle of the slopes. The piste caterpillar presses the snow into a compact blanket. A milling machine at the rear of the snow groomer is responsible for the loosely-packed snow on the surface. It «shreds» the snow and ice so finely that the snow left behind is as loose and powdery as freshly fallen snow.

Pistenpräparation am Metsch
Piste preparation at Metsch

Completely fresh!

The snow finisher puts the final touches on the perfect ski slope

The thick rubber mat creates the typical diagonal grooves left in the snow. This is more than just a visible feature of a freshly groomed piste.

The surface area of the piste is enlarged by the grooves. The bigger the surface area is, the better the sintering process which now begins and needs a lot of time. Ideally eight hours before the first guests come whooping in, taking possession of the virginal slopes.

Sintering is the process in which individual snow crystals combine with each other without melting. The closer the temperature is to zero degrees, the better the process works. Over time, the combined snow crystals form a stable and solid base layer without becoming icy.

This results in a compact slope with a firm grip

In the past, the snow groomers worked during the day. No longer being able to spot them during the day doesn’t mean the mountain resorts are trying to be more economical. There are two good reasons why.

Firstly, snow groomers are naturally bulky and awkward machines that are still capable of moving. Soft, quick skiers and hard moving machines do not get along well on the slopes – the result of close contact would always be unpleasant.

Secondly, as described above, after grooming the slopes need a lot of time to even become compact. Directly behind the finisher, the fresh slope is soft and it would not take long before it looks even worse than before it was groomed.

Nature has the last word

New snow is always good, except at night

If it snows at night, the men who still want to do a good job are left to make a choice between only two not-so-satisfying options. If they work through the night, the piste is sure to have enough time to sinter and become solid. The next morning it will not take long, however, for the fresh snow covering the piste to be chaotically distributed across the slopes; thus taking away from the beautiful piste views.

If the men first start work in the morning at the usual 3 a.m., the slopes, depending on the temperature, do not have enough time to become solid. In every case, the result is unsatisfying for the finicky night shift workers. Ultimately, it must be admitted here that skiing in the 21st century is, fortunately, still about experiencing nature. Not every detail can be controlled by humans.

Pistenpräparation Nacht Ratrac bei Schnee
Piste preparation by night while it’s snowing

Taken on the leash

Some of the snow groomers have a crane-like structure mounted onto them. This is a winch which is coupled with the motor. The wire cable can be up to 1’200 meters long. Attached to a fixed anchor point, the steel cable can be collected and unrolled in a controlled manner. The wind is not powerful enough to pull the machine up the slope. But it supports the snow groomer. The piste caterpillar, thereby, is less likely to lose its grip. Skidding on the slopes is far from good. The heavy machines would dig through the blanket of snow in a flash and leave behind ugly holes.

The long steel cables are, however, not completely harmless. The cables could become potentially life-threatening, especially for nocturnal ski-freaks. When the snow groomers change from one side of the slope to other via cable, the finger-thick cable initially remains hanging in the snow. Only after a pull, does it dart from one side of the slope to the other. Those standing in the way would not have much of a chance. The official opening times for the pistes (respectively the last patrol) are therefore meant to be taken seriously and should be abided by.


Ratrac mit Seilwinde
Piste vehicle with a leash