A snow groomer (informally called a "piste basher" in the United Kingdom) is a
tracked vehicle equipped in front with a
shovel (or dozer blade) and behind with a cutter (or roller). It is usually driven by diesel engines. When the machine drives over a snowfield, it pushes snow ahead of it and, at the same time, smooths out any surface unevenness. Snow groomers built for ski slopes employ front mounted, hydraulically operated blades, powered rotary tillers and specialized shaping equipment for not only maintaining
ski slopes, but also for building
half pipes,
terrain parks and snow tube parks.
Cross-country skiing trails are also groomed in similar fashion, often with a wide "corduroy" area that allows skate-skiing plus classic ski tracks, imprinted with specialized ski guides. Manufacturers include
Kässbohrer Geländefahrzeug (Germany),
Prinoth (Italy),
Tucker Sno-Cat (US), the Ohara Corporation (Japan), Zaugg (Switzerland), Favero Snow Tech (Italy) and Aztec/CM Dupon (France). Snow groomers can handle very steep gradients due to their low
centre of gravity and large contact area, but they can also be assisted by
winches. Using cable lengths of up to 1,200 metres and a tractive force of up to 4.8 tonnes, winches can support the machines on steep slopes. Snow groomers warn skiers and snowboarders with visual or acoustic signals. Groomers are mostly sent out during the night time after the close of the
ski area so as not to interfere with daily and
night skiing. Due to their mobility and low
ground pressure (typically 0.040 to 0.060 kg/cm2 (about 4 to 6 kN/m2) snow groomers are sometimes used elsewhere, e.g. for agricultural purposes, moving bulk goods, working on
peat bogs or at
biogas sites. == Snow grooming equipment ==