by Dennis Doyon, contributing writer, June 12, 2020
Grooming equipment and operator expertise ensures the ultimate trail experience for cross-country skiers, snowshoers, and hikers at North Highlands Nordic in Cape North. The 12km trail system is maintained by a PistonBully PB 100 tractor, and groomed to a width of 16’. It’s the only XC trail system in Nova Scotia maintained by a tractor-style groomer – the optimal machinery used to produce pristine, consistent trail conditions for skiing including classic and skate techniques.
Behind every expertly maintained trail at North Highlands Nordic lies a strong community that works to find resources, recruits volunteer power, and perseveres to ensure everyone gets a chance to enjoy these facilities – through school try-it programs, youth programs, inclusive membership pricing with youth equipment loans, affordable rentals, weekly group ski/snowshoe/hike events, loppets, & more.
NHN’s snow coverage is among the most consistent and dependable in the Maritimes, operating daily each year from late December to early April. Plan your visit to this welcoming winter wonderland – there’s something for everyone and plenty of friendly folks willing to lend a hand. For additional details on rental equipment, weekly group outings, and lodging – visit www.nhn.xcski.ca.
Grooming with a PistenBully Tractor
Contributing writer Dennis Doyon explains part of the science of grooming cross-country ski trails with a PistenBully tractor that is specifically equipped for this task. Dennis is a Nova Scotian with extensive volunteer experience across many roles in cross-country skiing – from grooming trails, to serving on the board for our national governing body, chief of race official at national competitions, and more. Review his volunteer experience in the final paragraph of this article.
NHN’s PistonBully groomer in action during all hours of the day, producing high quality cross-country skiing conditions. We would like to extend a special nod to the skilled volunteer grooming team.
Overriding Concept
When fresh snow is agitated it momentarily experiences a slight temperature rise due to relative heat of friction. This momentary rise in temperature is quickly followed by a return to the original colder temperature, resulting in a changing of the snow from its original “fluffiness” to a more solid texture capable of supporting skier weight and maintaining a molded track. This stiffening is referred to as “setting up” and the agitation is referred to as “artificially aging”.
The agitation can be caused by all manner of snow manipulation, from simply stomping down with one’s feet, to driving over the trail with a track vehicle, to the use of large drum rollers to the ultimate tool, the snow tiller. The tiller, specifically designed for use on XC ski trails and alpine ski slopes, is mounted on the rear of the tractor and employs a high-speed revolving drum studded with short tines that create a high speed agitation; the tiller then uses hydraulically-controlled down pressure to press the momentarily marginally-warmed snow into a desirable surface. Then tracksetters, attached immediately behind the tiller, press the ski tracks into the trail surface just before the snow begins to stiffen (or “set up”).
The tiller is also used very effectively to change icy, possibly frozen tracks from the previous days’ skier use into a new, uniformly fine-grained snow surface. This is especially desirable in our maritime climate where the air features high humidity content and temperature fluctuations can result in freezes when warmer temperatures drop. (Such conditions, especially if rain is involved, often result in ski areas issuing statements to the effect that“…grooming will begin once temperatures drop below freezing…”, meaning that the grooming crew will let the wet trail ice up and somewhat dry out before using the tiller to change ice particles and frozen crud into a fine-grained uniform surface.)
The “front end” of the tractor features an articulated plow. What first appears to be a U-shaped plow is actually, on closer examination, a three-piece assembly consisting of a larger centre plow with a hinged side-blade on each side. The entire structure is mounted so as to be hydraulically raised and lowered. It can also be angled diagonally from the horizontal. Finally, the two hinged sections can be swung to change the U-shape into a straight design…or, swinging only one of the hinged sections creates an angle plow that can “grab” snow from one side of the trail and slide it to the opposite side. The versatility of this design is especially useful in areas that experience heavy snowfalls that are sometimes accompanied by windy conditions resulting in severe drifting. Using the angled plow the operator is able to level a drifted “side hill” condition, resulting in a trail that’s once again level side-to-side.
A “normal” grooming session (one with little to no overnight snowfall) might entail tilling and tracksetting with the tractor over the complete ski surfaces of all trails (usually requiring two separate passes to achieve the desired 16 foot width). A ski area with 12 km of trails requires the tractor to travel over 24 km over a few hours. On the other hand, a heavy snowfall may necessitate dividing the process into multiple steps covering two to three times that distance:
- The tractor might first make an initial packing/plowing pass, using the tractor’s travel tracks to pack the deep snow into a more manageable depth. At the same time, drifts are eliminated or modified using the plow;
- Once the packed trails have had a bit of time to “set up”, the operator makes a second series of passes, this time using the tiller to “artificially age” the snow. The tracksetters may be lowered at this time to create the “set track”; during extreme conditions, however, the tracksetting step may be delayed until the tilled snow more permanently sets up and a third series of passes is taken to again till, this time adding in the tracksetting.
Wear and Tear
Regardless of whether new snow falls or not, in the course of daily use trail surfaces will show signs of deterioration, whether from frequent skier/snowshoe use during the day or the occasional visits by moose who enjoy the firm footing afforded by the groomed surface. Consequently trails are frequently re-groomed (“renovated”) to eliminate all irregularities and to return the surface to pristine conditions. At good ski areas this renovation occurs on an almost daily basis.
Photos
Plan your next adventure skiing, snowshoeing or hiking. There’s a trail for every ability.
Dennis Doyon | Contributing Writer | Experience Highlights
Former Trail grooming contractor/operator for Cape Breton Highlands National Park; Former grooming operator, NHN; Former chair, Nordic Ski Nova Scotia; Former board member, Cross Country Canada; Cross Country Canada Level III official; Chief of Race, ’87 Canada Winter Games and ’89 Canadian Junior XC Ski Championships.
Cross Country Nova Scotia 