SNOW GROOMING

SLOPE GROOMING AND SNOW CONDITIONS

I was going to give details on grooming and snow conditions but I found this article on the Falls Creek page and thought it worth putting here. Grooming makes the snow last longer and the skiing better for most people, Falls Creek are also careful to leave enough areas for those that prefer it a bit rough.

I spent a night out on a groomer, its an amazing job, these guys do lot more than just drive up and down the slopes, they know the snow, how to work it and are very fanatical about getting the best result while doing minimal damage to the slopes.

This information sheet is intended to give the skiers at Falls Creek a brief introduction to the Slope Grooming Operation and how the changing snow conditions can affect a skiers day.

A GROOMER NEAR THE FALLS CREEK SKI LIFTS OFFICE MAY 2000

The material ....... Snow and it's changing nature. Snow falls in various forms. Temperature and atmospheric conditions combine to form anything from dry powder to soft hail, each presenting different problems for slope preparation. Fresh snow contains ice crystals, linked together, and containing a great deal of air. By compressing or packing the fresh snow, some of the air is removed, and a load bearing surface is created. Beginners need this load bearing surface to be able to turn.

Fresh , powdery conditions can last for weeks without any further snowfalls, if the temperature remains well below freezing. In Australia this is rarely the case. Within a few hours, the passage of skiers, and temperature fluctuations have begun to melt the snow crystals. Once this water has formed in the crystals, an overnight temperature drop will create a binding affect, and the slope becomes hard and icy.

This process of thawing and refreezing may take place hundreds of times in a few weeks and eventually the crystal structure deteriorates, to become a collection of small balls of ice, surrounded by water. This "loose snow" has very little binding between the grains, and is common in high traffic areas and Village roads. "Spring slush" and "sugar" are two types of this loose snow. This type of snow is very easily moved by skiers and huge bumps can form within hours. It also offers very little traction for grooming machines.

GROOMING IN THE FREAK MAY 2000 DUMPING

Spring snow also accumulates dirt, and this darker colour combined with the poorer reflective power of it's structure, causes the sun to attack it rapidly. Not only does it melt, but it can also sublime directly from a solid to a vapour, during a warm north wind. These effects can cause a rapid end to a good ski season if the weather is not favourable in Spring.

What is a Grooming Machine and what can they do for the skier The grooming machines at Falls Creek are made by Kassbohrer in Germany. Kassbohrer's are a specialist machine, specifically designed for ski slope maintenance. They have a 12 way blade on the front of the machine and a rotary "snow tiller" on the rear of the machine. The tiller also has special finishers to give the characteristic "corduroy" groomed product. The tracks are very wide, to give maximum traction in soft conditions.

Two of the snow cats are special Winch Cats, designed for steep terrain. These machines can hook onto anchor points, and winch up and down the steeper slopes, without sliding . They also have the capability of pushing snow uphill, to preserve the ski slope.

FALLS CREEK WILL CREATE THE PERFECT HALF PIPE

The work the Kassbohrer's do is vital to maintaining the quality of the skiing terrain. Skiers not only seek out the groomed slopes, they demand them. The corduroy finish formed by the tiller, is the end product of many tasks performed during the night. These tasks may include

Smoothing bumps and moguls
Maintaining snow depth in high wear areas
Reshaping and rebuilding ski trails
Stockpiling snow reserves
Pushing out wind fences and snow drifts
Removing excess snow around lift stations
Filling creeks and covering rocks
Spreading "man made" snow
Packing of fresh snow

All ski lifts are level sensitive at the load and unload Stations. These levels must be maintained every day by either pushing fresh snow in or removing excess after a storm.

HOW TO CREATE THE PERFECT HALF PIPE

Kassbohrer's can move masses of snow with their blades, and there is hardly a run on the mountain that hasn't been sculptured and reshaped to suit the skiers needs. Some types of snow are very poor skiing unless groomed. The snow tiller can improve the finish and create a decent ski surface. The snow tiller spins at 1900 rpm and can process snow that is not groomable with other implements.

Operations and grooming hours Falls Creek has 10 Kassbohrer groomer's which include four of the latest design. Up to 80 hours are spent each night working on the ski slopes. The work is divided into two shifts;

The Swing shift (4.30 pm to 1.30 am) and the Graveyard shift (1.30 am to 10.30 am ). Due to safety considerations, the machines must be off the slopes during the Ski Lift hours and no grooming is done during the day. The department has up to 17 full time operators and three maintenance mechanics.

OPERATORS

The operators are a mixture of highly experienced local people, experienced Canadians and Americans and several local trainees.

Summer grooming is also important. The work is mainly slashing and maintenance of regrowth. Creeks are piped, rocks are removed, intersections improved and trails are widened, to increase the skiable area during poor snow depth periods. The summer grooming program has made the skiing more reliable and has increased the ski area considerably over the last 6 years.

What areas can you expect to be groomed each night The groomed area is governed by the conditions, but when the whole mountain has enough snow , nearly every slope is maintained regularly.

EVERY NIGHT TRAILS

Wombats Ramble, Broadway, Last Hoot, Junction, Days End, Lower Denis', Skyline, Final Muster, Orry's

Runs Panorama (both sides), Towers... Main St and Highway 83, Tom Thumb, Lakeside... Powder Keg and Funnel, Scott Chair... Scotties and Corkscrew Gully, Playground (both sides), Ruined Castle Chair... Ruined Castle, Racetrack and Big Dipper South Face, The Bowl, Village T bar.... Village Run and Short and Curly, International Poma ...... Zipper ,Grand Couer and Jigsaw, Summit Chair... Oeste Wand or Slot, Headwater.... Barbigal,

This is the minimum standard and covers about 80 hectares. In good conditions this can go to 128 hectares.

THE CONVERTED KAT USED ON MT McKAY SKIING

When conditions are good, the groomed area will increase, and an extra run will be included for nearly all lifts. The terrain in "The Maze" and areas such as Darkside and Rapunsels will get extra grooming. After snow storms, the machines spend most of their time pushing snow from the "level sensitive" lift stations, removing snow drifts and making sure the lifts will open on time. The amount of grooming is restricted to the priority beginner and intermediate areas, as the machines struggle to keep up with the storm. It generally takes at least 24hrs to get the grooming back up to the normal area standard, after a storm. Poor visibility can also hamper grooming operations during storms.

CONSERVATION OF SNOW RESERVES

Falls Creek has a finite amount of material to be spread over the mountain. Skiers push masses of snow down the hill every time they turn, and if a snow cat operator can't get it back up again, then the slope will begin to deteriorate. Stockpiling, wind fences and good grooming techniques are as important as snowmaking, when it comes to making a slope last the whole season. The high wear zones and sun affected slopes are constantly maintained to make them last. Summer works are often specifically designed to increase snow retention.

TYPES OF SNOW AND THEIR ASSOCIATED GROOMING PROBLEMS
FRESH SNOW

Fresh cold snow is a groomers delight, and maximum groomed area, with a first class finish can be achieved. These are the best conditions, for all skiers.

Fresh snow can also fall when the temperature is not cold enough for good skiing. This "heavy powder" or gluggy snow is very common in Australia. This snow is as difficult to groom, as it is to ski. It glugs together and won't spread evenly, creating major grooming problems on steep terrain. A poor finish can result, but it is still easier skiing, than the ungroomed, heavy powder. After 24 hrs the grooming conditions improve and an excellent finish is again possible.

MAN MADE SNOW

Man made snow can behave very similarly to wet powder. This snow requires a 24hr "curing time" before any successful grooming can take place. Sheet ice and chunky lumps can result if this curing time is not allowed. The curing time can cause a "priority snowmaking area" to be uneven and covered with "whales" for the first skiing day after production. Good management during the night, and more advanced snowmaking guns, have improved the snow quality of the raw man made slopes. The slopes are always groomed before snowmaking starts, and good snowmaking techniques during the night can result in a flat skiable slope, similar to packed fresh snow.

THE CONVERTED KAT USED ON MT McKAY SKIING

WET SPRING SLUSH

Wet slush or "loose snow" can offer such limited traction for grooming machines, that even intermediate slopes, are impossible to climb. Downhill grooming can cause a "wake" effect, creating large windrows and "death cookies" that can't be repaired until after a freeze.

Wet slush causes reduced groomed area, a poorer quality finish, short slope life and heavy snow loss. Conservation priorities can keep a slope ungroomed until conditions improve.

Wet slush begins to freeze, on a clear night, by about 9.00 pm. There is a period of one hour when grooming is almost impossible, as the snow is "going off". A sensible operator usually breaks for dinner, during this period and returns after the freeze.

If slushy spring snow has not had a good freeze overnight, even a groomed slope can form moguls by 10.00 am

SPRING ICE

Spring ice can become so hard, that slow "triple cut" methods have to be employed, to get a decent finished product. This can dramatically reduce the grooming possibilities after midnight.

The skiing will be hard and fast, first thing in the morning, but the slope quickly softens by 10.00am. Most good skiers, love the hard and fast conditions, but the weaker skiers generally stay away, until the sun has had it's desired effect. Spring skiing on the groomed slopes is excellent, provided the overnight freeze is strong enough to form a good base.

WINTER ICE

Winter ice is usually only a hard packed surface layer. Aggressive grooming can usually restore the skiability of the slope, by bringing up the lower layers.

SUGAR

Sugar snow is formed when "loose snow" is skied, while the temperature is below zero. The grains are dislodged by the skiers and they become separate floating particles. Sugar snow will generally bind together after grooming, if a sufficient "set time" is allowed. Spring slopes must be groomed as early as possible during the night to allow the maximum set time. The slope will then last till midday without moguls forming.

RAIN (WOOPS SAID THE R WORD)

Rain reduces the groomed area. The risk of opening up creeks due to the machines weight, can prevent grooming in some areas. Generally, rain packed snow offers better skiing, than trying to improve it with a snow cat.

STORMS

Storms can create drifts in level sensitive, lift related areas, that require many pushing hours to recover the ski lift function. Some lifts can be almost totally buried. The amount of pushing and clearing work can reduce the groomed area available to the early skiers. All beginner areas, intermediate areas and home trails become a priority. Expert skiers usually revel in the unpacked powder conditions until the machines can catch up to their normal schedule. Visibility or "white out" conditions can make life difficult for the groomers. It is just as difficult for the cat drivers to see where they are going, as it is for the skiers.

So get out there and enjoy the skiing. The slope groomers will be working all night trying to provide a 1st class product, in the variable Australian conditions.

A daily grooming report is available to the public each morning. It can make a big difference to a skiers day if he or she knows where to find the groomed runs.