I'm slightly concerned about just what is in the pipeline with this fencing after hearing about an Elephant Fence down the M1 Race Track - though the latest on the blog seems to be targeting specific areas.

The passing loop and immediately above passes through the Skirt of the White Lady - the most reliable line on the lower portion of the run that takes people back to the mid-station. This is a natural snow field shaped by the topography which accumulates snow esp well on drifting from South and West quadrants - accumulation is enhanced by the track leading to potential burial.

Large snow fencing has down-wind consequences. If you stop snow reaching the Funicular, you will also stop it reaching the White Lady.

On the CML blog Colin also writes:

"We trialled the cannon over the last two seasons for power and water use and how much snow it would produce. We now have a clearer idea of just what is involved in trying to produce significant quantities of snow."

They switched it on twice each season, and spent a minimum of £10,000 for the privilege. The first winter they hired it they only had the power socket for it in place in April, and nothing happened with the apparent plan of 'installing power points and sump to run it at the bottom of Burnside, and to keep a beginner area at the Shieling'.

I'm not sure that this trial could be considered anything other than lackadaisical, and as such I sincerely doubt that it could have resulted in any further understanding whatsoever of capabilities or what it means to make snow under varying circumstantial situations.

I can understand why you think that but to be fair I think they had enough snow, so much so that the team spent much time digging out the train tracks, to be asked to dig out the snow cannon could of been considered as taking the proverbial. Also I think the purpose of the trial was more to understand the power and water supply requirements than varying circumstantial situations. Also with the amount of snow CML focused on getting the area open as early as possible and once they are up and operating they don't really have that much capacity for trails. Though it would of been nice to see it run more than it did.

Also I think CML have visited other areas which I think you have to class as loosely similar (I say loosely as Scottish Highland condition's are pretty unique) to understand the number of snow cannons required to be effective, then its down to calculations - water and power supply for one cannon times the number of cannons to provide effective snow making. Just my thoughts on it

I guess there will be some compromise, but I think it is good that they are willing to try something to alleviate the drifting on the train track, lets hope there is not too much error in the trial and error. Plus the winchcat should be able to correct any errors fairly quickly and push the excess down to the lower runs. Lets hope it works and saves all the digging

This doesn't seem particularly credible. The equipment manufacturer can already tell you the power supply requirements, and how much water each individual snow-cannon would draw per hour based on different pressure settings. CML will know their system capacities at the pump house - they did not need to spend £10,000 on hiring a snow cannon to find out this information when a basic calculation would have sufficed.

What CML did need to spend £10,000 on hiring a snow cannon to do, however, was to understand how it operated under varying circumstantial situations. This is what they have not achieved.



Calculations are far from being that simple. While some pretty rudimentary parallels could be drawn between some areas (I presume you mean between Cairn Gorm and Scandinavia or Australasia?), how can you understand accumulation and ablation, and the true potential worth of snow-making on Cairn Gorm, by visiting other ski areas?

The opportunity was there for a proper trial, to test a piece of snow-making equipment in all conditions - from marginal temperatures, to high winds, to cold and calm days, to spring days with cold nights and warm days. With varying pressures to produce different densities, the opportunity was there to assess the volumes of snow able to be produced in differing scenarios, monitor effect of wind on different snow densities, and monitor ablation rates under the differing scenarios. From this information they could have made accurate projections about potential cannon numbers and the potential worth of the equipment.

The important part was understanding how the equipment performs under varying circumstantial situations, but as it was they appear to have simply switched it on twice a year when they saw that conditions were suitable, and saw that it indeed worked. They are therefore no further on in their understanding of snow-making than they were prior to hiring the snow cannon.

I work in the IT industry where proof of concept and the vendor standing up to their products capability are key to a successful solution/deal. I find it quite amusing that CML had to pay 10k to test out a snow cannon to prove that is was operationaly viable for the Cairngorm's fluctuating temps,winds and humidity. If CML had any procurement savvy they should have negotiated with the supplier that they prove the capability of the proposed snowmaking infrastructure at no cost to or at least minimal cost to CML and with the option of offsetting incurred costs against any future purchase.
This would have enabled CML to off-load the trailing process under CML supervision to the vendor who would have had responsibility to test and document the capabilities and value that the snowmaking kit would provide the CML winter operations.

As alan says, hopefully the new fencing won't further starve the white lady of snow. The train track already acts as a big enough fence stopping snow getting in there. I cant say the M1 ever seemed short of snow to me other than at the bottom below the race hut and you would hope the new winchcat could sort that out if necessary?

However, i shall commend cairngorm on any improvement work they do. They need to be encouraged in this regard in the hope that they do a lot lot more of it

Jamie/Rob123 - all fair comments - if the costs quoted are accurate then it was 5K a year for the time they had the cannon which turned out to be the best two consecutive snow years for a long time, I guess this would not have left them much spare capacity to trial the cannon to the extent you mention.

I also work in IT, Vendors will only invest if they see return for their money, I don't hear of any vendors falling over themselves to get a piece of the action with regard to snow making in Scotland, well not at Cairngorm anyway.



Edited 1 times. Last edit at 06.58hrs Sat 17 Sep 11 by daveski.

Then even more reason to keep the cannon for another year in order to perform a trial. Giving it to Glenshee having hardly used it will not have taught CML anything new about snowmaking.


That's putting a lot of unnecessary spin on it, Dave. For the past two years I have had to be in semi-frequent contact with several of the worlds largest snowmaking companies regarding the capabilities and specifications of their products. Some of the companies volunteered similar thoughts with regard to Scotland - and you'll forgive me for briefly quoting the president of one: "I often wonder with astonishment when looking at the ski areas in Scotland why only a few have invested in snowmaking". Alas, where there is no will, there is no way.



Edited 1 times. Last edit at 11.15hrs Sat 17 Sep 11 by Jamie.

Well he [president of a snowmaking company] would say that, wouldn't he!

I remain far from convinced that making snow on the margins of the snow-line (not to mention below it) is viable. Lack of snow on Scottish mountains is more the product of thaw than lack of precipitation. The problem is that if the precipitation is rain (as often the case) ... then all the expensively generated artificial snow gets washed away.

We need to respect snow as a bounty of nature. The Alps are far more conducive to snowmaking because they often experience prolonged drought but temps way below zero (Zermatt is a good example).

The snow farming project on Cairngorm - shifting the ploughed snow from the car park to patch or build the lower slopes - is probably more sensible.

David, without actual hard data, no one can say it is not possible. The 'it's Scotland it cannie work' line is no longer credible.

Once the Cas Gunbarrel is relatively well filled, it does not just get washed away when a warm sector comes through.

A good section of the Burnside run is only 4-5m wide - a very modest area for snow making which could have a dramatic impact on skier numbers. Analysis of skier days vs days skiable to carpark indicates the positive impact of being able to ski to the Daylodge is huge, equivalent several hundred skiers per day on average.

On the subject of the Funicular, drifting / digging out and snow fencing, this photo from Tuesday 22nd Feb shows the problem area through the Skirt of the White Lady nicely:



Full Size: [www.winterhighland.info]

The next photo taken on 25th October 2010 shows the Funicular track nicely, with the dusting of fresh snow providing a good contrast to the track:



As can be clearly seen in that photo the height of the funicular above ground diminishes as the track climbs through the Skirt, from being high enough to ski under at the passing loop to the track bearing beams being basically at ground level at the top of the Skirt.

Obviously re-profiling the superstructure to increase track height to allow the snow to drift underneath will no doubt be out of the question due to both cost and lengthy closure of the Funicular.

The distance between the Funicular track and M1 Poma measured from an aerial photo is about 20m. Esp with a topographical enhancement to the M1 Poma fencing, the funicular already lies within the potential drift shadow of the Poma uptrack fences. That rules out an elephant fence between the two.

Given a saturated drift profile of a snow fence is approximately 35x it's height, a 4m elephant fence even replacing the lower Race Track fence, may merely shift the problem to the Poma.

It's also worth considering that the capacity increase of a snow fence with height is a square law - A 3m high fence would store 4x the volume of snow. Thus such fences where there is a long upwind fetch will have a very significant effect downwind. In SE through West winds starving the White Lady of snow, while if snow predominantly comes from the North through East, reducing snow reaching the Cas Gunbarrel.

Potentially damaging two of the key signature runs on the mountain would be a heavy price for reducing burial risk of the Funicular. The renascence in the White Lady in recent years almost certainly has helped bring people back to the mountain.

Alternatives?

CML have a new much more powerful Piste Basher than was available in 2010. Instead of adding more and bigger fences, try this season removing the lower most fencing on the White Lady in it's entirety (the banana shaped section of fencing which points into the top of the passing loop). Thus allowing the machines free reign to keep removing snow from the immediate track side to stop it building up to a depth, where a problem may result.

Similarly remove the fencing on the other side of the track, where neccessary mark it off with movable poles, so again the machines can get in and push the snow out from the hollow by the track.




Edited 3 times. Last edit at 13.52hrs Sat 17 Sep 11 by alan.

I can only presume that you are referencing my projections referenced in the Scotsman newspaper for snow-making on the Coire Cas to Glenmore stretch? Lack of snow on Scottish mountains is more the product of factors which do not arrest ablation in particular areas. I think what you are missing out on, David, is that daily ablation has been calculated.

Where would you say the natural snow line is? Bob Clyde reckoned (1981) the 'minimum reliable' base-elevation on Cairn Gorm was 760m, and 'completely reliable' at 850m. We know that 600-630m is the base elevation of most ski developments in Scotland, and Clyde reckoned that this would see skiable cover for 50% of the average season. This is on open slope, and he pointed towards factors such as gully storage as decreasing the base elevation of skiable snow cover.

But gully storage is not the only factor that can promote snow longevity in this country. Look to Clashindarroch Forest at Huntly, where the Nordic ski trails are between elevations of 360m and 510m, with the site varying from dense plantation to thinned mature larch plantation to open moorland. The base elevation of 360m is similar to Glenmores, and far beneath where you consider the snow-line to be. However, in the years that have been recorded (from 2003 to present) an annual average of approximately 45 ski days have been possible at the Clash each winter (with a minimum of ~21 in 2007, and a maximum of ~108 in 2010). Here the positive effect of different micro-climates, primarily through provision of a sheltering biomass promoting snow-longevity, can be seen. I noted extraordinary snow longevity on a site visit in mid-March this year: despite south-facing tree-lined trails experiencing full exposure to the midday sun, a cover of firm snow continued to endure in these locations. This was in stark contrast to areas which were only lined on one side, or not at all, where no snow endured - regardless of aspect.

My recent university thesis used the failed 1960s Mar Lodge Ski Centre by Braemar as a case study upon which I examined the influence of snow-making equipment towards ski area viability both at its time of operation (1960s) and now. Within each scenario was a comparison between different standards of snow-making equipment (the primitive equipment they used in the 1960s, and modern equipment), between different exposures (open slope and forested), and between different aspects and elevations.

Using degree-day modelling techniques calibrated in the Mar Lodge catchment of the Cairngorms (as published primarily by Dunn and Colohan in various peer-reviewed journals in the late 1990s and early 2000s) I was able to predict daily snow ablation based on a series of variables: temperature, solar radiation, rain, aspect, slope openness... Most of these factors alter daily, while the latter two are kept constant throughout each scenario.

Doug Bryce mentioned on the Glenmore Gondola topic that I did not include wind as a variable in my calculations, and this is correct, and was done for a number of reasons: to begin with, there is a peer-reviewed hydrological paper (I will look up the name) which considers that on Cairn Gorm snow drifting is minimal beneath the 2000ft contour (my area of study was beneath this elevation band). Add in factors of a tree-lined and north-facing slope (considerable shelter from prevailing winds), as well as high density snow produced by snow cannons (more resistant to wind-drift, both in air and on the ground), as well as the mobility of snow guns (i.e., angle of production can be altered, guns can be moved backwards into the wind), and I consider it entirely reasonable to exclude wind drift from low-elevation snow-making calculations such as for the Coire Cas to Glenmore stretch. Please note that it is a factor which would absolutely have to be included in the production of any snow-modelling calculations above the 2000ft contour, and hence while my study has certain parallels to the present Cairn Gorm ski resort, parameters would have to be altered before direct parallels could be drawn.

The snow-making equipment I chose in my modern study was the Ratnik Sky Giant IV which starts up at -1.3°C wet-bulb. This has already been superseded by the Sky Giant VI which can start up at -1.1°C wet-bulb. Snow accumulation is calculated based on the number of hours per day for which the temperature was beneath the snow-guns start-up temperature (-1.3°C wet-bulb for Ratnik Sky Giant IV). I know how much water each gun can output, and the area requiring covered, so therefore (based on the industry standard snow density of 407kg/m^3) can build up the snow pack depth based on that. For info, in a single Sky Giant IV can produce 31.1m^3 of snow every hour at a middle-of-the-road pressure setting in marginal snow-making temperatures. The predicted daily snow depth is therefore simple the daily accumulation minus the daily ablation, and compiled over the course of a season.

What I expected to find was that modern snow-making equipment would have made the south-facing and low elevation (335m - 505m) Mar Lodge Ski Centre just viable at the time of its operation (in the 1960s), but certainly not in modern years. My requirements for a viable development borrowed the Alpine standard of 100 ski days and a minimum snow depth of 30cms for skiing to be possible. What my results found was that with 10 middle-of-the-road modern guns the development would likely be borderline viable today. If that slope was instead north-facing, and forested, I project well over 100 ski days per winter, even in the worst of modern winters, with just 10 guns. Note the parallels here to Clashindarroch and Glenmore.

To give this some perspective, Thredbo in Australia receive an average of around 200 snow-making hours at village level per season, and their snow-making plant has increased ski days to the village from an average of 19 days to just over 100 days (5 fold increase, and that's a fact - not a prediction!). To put that in perspective, in recent years Mar Lodge would have had the following numbers of snow-making hours - at an elevation of 335m (using Sky Giant IV - so the number of hours between November and April where the wet-bulb temperature is beneath -1.3°C):

2006/07: 270 hrs
2007/08: 703 hrs
2008/09: 737 hrs
2009/10: 1196 hrs

Extending the study to the Coire Cas to Glenmore stretch, using the assumption of 10 guns (for the length of the ski road, which is 3.9km):

Assuming piste width = 20m:
2006/07: 110 days (average snow depth = 48cm)
2007/08: 143 days (average snow depth = 95cm) - still open at end of April when my chart stops!
2008/09: 155 days (average snow depth = 102cm) - still open at end of April when my chart stops!
2009/10: 144 days (average snow depth = 127cm) - still open at end of April when my chart stops!

To be even more pessimistic, to a width of 25m (the standard piste width I used throughout my thesis):
2006/07: 100 days (36cm average)
2007/08: 137 days (89cm average) - still open end of April.
2008/09: 154 days (88cm average) - still open end of April. Just!
2009/10: 142 days (119cm average) - still open end of April.

My graphs demonstrating altering snow depth throughout the course of a season have shown me that the key is in being able to produce sufficient volume of snow to withstand any periodic thaw events - at present, Glenshee and the Lecht make 'just enough' to cover the brown patches, so it is no surprise that their artificial snow is washed away by the next thaw.

You will be aware that it is widely considered in peer-reviewed journals that North-East Scotland is expected to warm least out of anywhere in the UK. You will also be aware of the UKCIP09 climate projections where, based on their mean warming projections, 2007 can be considered to have been a warmer year than what they predict the mean 2080s average to be (their mean projection for the 2080s is +2.2°C with respect to 1961-1991).

It was considered at an international conference on winter tourism in 2003 that the most important for a ski resort to being technically viable is not so much in traditional factors such as climate, aspect or elevation, but rather in that ski resorts ability to adequately produce artificial snow.

With 2007 being a year considered to be out of the ordinary - both now and probably in the 2080s, it is because of the UKCIP09 climate projections that modelling snow-making capabilities in the past 5 year period can be considered so significant. If snow-making can be shown to produce 100+ ski days in 2007, would it be unreasonable to assume (referencing climate projections) that snow-making technology would continue to prove viable into the future? Also note that technological advances in the start-up temperatures of snow-making plant are presently far outstripping the rate of warming.

Two years ago I too was far from convinced about any of this, but following 1,600,000 cells of calculations it is now my absolute opinion that the old rules towards ski area viability have been thrown out the window. The idea of skiing beneath what you might consider to be the snow line can be seen on the ground as working due to protective biomasses at Clashindarroch, can be seen as working with provision of artificial snow-making at Thredbo, and it is my absolute opinion (backed by modelling) that with a combination of snow-making and a protective biomass we can see it work on the tree-covered north-facing slopes from Coire Cas to Glenmore.

Finally, I reference quotes attributed to CML employee Cathy Mordaunt in the book 'Snow Tourist' (2008):
Cathy, the mountain's ecologist, told me how the company planned to take lifts out at the bottom of the mountain and reinstall just a few of them at the top ... "We are losing infrastructure because we no longer use it - we no longer can use it", she continued, "we will gradually retreat up the hill"

I believe there is another way.

As I have said before, just look at the Sunnyside pomas at Glemshee - low level, west facing, but the upline lasts all season, even with natural snow, when it is full. The "trench" that the tows run in replicate a gully effect on snow capture and depth. If the same topographical strategy is used when snow making (ie pistes formed by banking to the side plus snow fences), the snow will last longer. The artificial snow would supplement the lower snowfall at lower and mid levels, in order to achieve sustainable depths for the season.

Zermatt is a bad example to quote. It has a surprisingly low natural snowfall, and there's a lot of rocks to cover, particularly at the very high altitudes that their snowmaking extends to. I suggest you visit a wider range of mid-level centres over the summer, and have a good look at how the pistes are now engineered to achieve this gully affect, especially where they have snowmaking. The strategy is very much as a priority to create thin-width season sustainable ribbon pistes, and once those core pistes are established, they turn their attention to the rest of the mountain for supplementary snow making and farming.

Respect to alan, Jamie and Hipennine for those very interesting responses to my points.

Obviously I'm happy to be proved wrong, but something seems to be holding Cairngorm back and ... question ... how much snow did The Lecht make last winter? I got the impression (only from viewing webcams) that they'd decided to make a lot less snow. If that's correct ... why? If anyone from The Lecht is reading this and is willing to share some data this would be interesting, since that centre is presumably now the most experienced user of snowguns.