LAUBERHORNRENNEN (Wengen) Piste Illegally Prepared

A snowHead

In the swiss Newspapers this morning . No time to translate but they are claiming illegal Artificial Fertilisers were used to prepare the piste or the race wouldof been cancelled. This is a danger to Ground water.

http://www.espace.ch/artikel_306904.html

A snowHead

I know they used that ammonium nitrate , thought that was common knowledge. Is that what's illegal?

It seems strange they can do that when we aren't even allowed to salt the paths. Puzzled

Well, the person's real but it's just a made up name, see?

so I'm a bit more awake now and ready to deal with german.

Appears they used as much fertiliser for ther slalom course (less than a hectare) as what a farmer would use for 14 hectares over a year. And in the winter plants don't absorb it so it runs straight off into the water supply. Seems it was that or cancel the race.
To be honest the village was destroyed by last weekend, the pistes were ruined, now the ground is full of nitrates. Seems to me no alternative but to outlaw and ban skiing, possibly with a death penalty. Toofy Grin

Around the end of the season the race track always comes back, as the snow melts, it's still blue and icey Laughing

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Is the fertiliser to make the snow grow quicker?

Anyway, snowHeads is much more fun if you do.

petemillis, sort of, by adding the fertiliser to the water you change its properties so yes in effect you make the snow (well it's more like ice) grow quicker, the Swiss are normally very strict on enviromental issues (woe betide you should you put recyclable material in your non recyclable rubbish bag). I guess that the financial aspects of not running the race caused someone to ignore the enviromental issues

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At the same time, putting anything in snow/ice will lower it's melting point. It must be a very fine calculation, to get the volume, but have it last.

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I have only ever seen salt used in France. Obviously it will still get into the water but you don't have to keep the bags locked away.

After all it is free

rjs, they won't use salt in Switzerland because it will kill the grass underneath, not a good move when it's used as alpine pasture in the summer

I beleive its the stuff they used to add to the water to make artificial snow at above Zero Temperatures.

This was outlawed in Austria, Switzerland some years ago.

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Ah in this case I think what they did was scatter fertiliser over the top of the piste, this raises the freezing point of the snow and causes the surface to harden. The slalom course is all at fairly low level and would have suffered extensively in the recent warm spell

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D G Orf, You don't need very much if you are just scattering it on the surface.

They will probably have used a piste basher to churn up the top layer of snow, then mixed in the fertiliser before bashing it flat again.

Works like this apparently:

How do they work? These materials must first come into contact with free moisture (liquid water) and combine to form a brine solution. They cannot work in their solid state. Once a brine begins to form (in solution) it drains through the snow pack until it reaches the ground surface.
The key to the process is that the brine solution has a lower surface tension than water. Wet snow holds its water on the surface through, among other mechanisms, surface tension and hydrogen bonding. When the water mixes in solution with the salts it forms the brine. The brine solution has a lower surface tension, and free hydrogen radicals are captured that reduce hydrogen bond strength. Consequently, the water can more easily drain downward through the snow pack.

This is the secret to the chemical's effectiveness on a race course. Fundamentally, it drains off excess moisture in the snow, and compacts the ice crystals together where they can re-freeze into a firmer mass. This is why the FIS refers to these materials as compacting agents. This process can help explain why potassium chloride and urea are more effective than rock salt at air temperatures above freezing: the endothermic nature of the reaction assists the compaction and re-freezing of the snow pack by removing some latent heat from the snow pack.

What did I just say? I basically said that, in order for the materials to move into solution they require a little energy. They take that energy, in the form of heat, from the snow pack. The heat that is conducted from the surrounding material (snow) to facilitate the solution is known as the latent heat of solution. The latent heat in the snow pack is surrendered to fuel to reaction that forms a brine solution. In a similar manner, the mere act of mixing Kool-Aid crystals lowers the temperature of the mix water a tiny amount.

However, every upside has a downside as well. The endothermic materials are almost ineffective in dry snow, as they require free moisture to move into solution and drain through the snow pack. The exothermic chemicals can create enough heat to extract moisture from the snow, but that moisture may not drain through the pack very far before re-freezing. This is undesirable because a hard crust is formed that may fracture and cause other problems.

Also, exothermic chemicals require greater care in application because they require a good mix with the snow, and good contact with the snow, to kick over the reaction, render them into solution, and release their heat.

http://home.eznet.net/~vraguso/Book_2/Courses.html#12.2.3%20How%20the%20Chemicals%20Work

You know it makes sense.

laundryman, It does lower the freezing point of the bit of snow containing the additive.

Otherwise you'll just go on seeing the one name:

They mixed fertilizer in with the snow, to raise its freezing level. This retards its melting.

A snowHead

telford_mike, that explanation of process - leading to a change of consistency and the temporarily removal of heat - sounds about right to me.

rjs, we agree.

Whitegold, no and no.

A snowHead

Yes and yes.

The worldclass New York Times / International Herald Tribune would seem to agree wink

"Organizers also put fertilizer in the snow to raise its freezing temperature."

http://www.iht.com/articles/2007/01/10/sports/ski.php

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Whitegold, show me an academic source that says so and I'll pay attention.

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Whitegold, try this for size, from Purdue University:

http://www.chem.purdue.edu/gchelp/howtosolveit/Solutions/fp_depression.html

Note the last line: "The freezing point of a solution will always be lower than the freezing point of the pure solvent." (their italics).

It's called a "colligative" property: something that depends on the amount and not the nature of the additive.

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Ah I think I see where the conflict arrises, the addition of the additives lowers the freezing temp of water, however its action on the surface of the piste is not what might be expected, here it causes standing water to drain through the snowpack and in doing so makes a more compact surface. Thus the effect of the additives is an apparent solidifying of previously melting snow so an apparent raising of the freezing point when in actual fact the freezing point has in fact gone down.

I guess it's just one more wierd effect that you get with water

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D G Orf, that's about it, I reckon. It may also lower conduction by draining standing water.

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Cool - many thanks snowHead

for the explanamanaishun.

After all it is free

Well if what they say was done is true, then it seems a little off that they were saying how such an invironmentally friendly resort it is.

This has been an interesting read!

Mr.Si, I suspect this is one of the reasons that the press is covering it, Switzerland as a country is far more into enviromental issues than say the uk, one of the reasons that Swiss and Austrian resorts don't get as much use from artificial snow is because they don't stick addatives in the water because they can damage the summer pasture, now many years ago there was far less commercial involvement in the WC races and therefore less pressure to ensure that the races are run in poor conditions, last year in Wengen there were 3 video walls (Wengeneralp, Wengen and Innerwengen) multiple hospitality tents, and a helicopter parking area at Kl Scheidegg it's the skiing equivalent to an F1 Grand Prix event.

I would imagine that there will be an inquiry into why the fertaliser was spread, who authorised them to spread it and weather or not such a thing will be allowed to occur at future events

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I hope they throw the book at them Very Happy

The problem with the slalom course is all the snow there drains off into a stream at the bottom. heard today all the chemicals will promote algae growth in the spring. I have a farmer friend who's a bit shocked they were allowed to do it, if they were indeed allowed.

For sure they looked at how much money they would lose cancelling the race and how much the fine would be for using chemicals and decided to go for it.
They will just blame the military and nothing will happen most probably.

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telford_mike, Fascinating discussion on the physics of how the ammonium nitrate "compacting agent" works - thanks for that info

laundryman is of course quite correct about the melting/freezing point being lowered - I suggest Whitegold shouldn't use any newspaper as an authoritative source for scientific facts! Toofy Grin

On the environmental front, I wouldn't be surprised if the runoff does cause a local algal "bloom" in any nearby ponds. Knowing how strict the Swiss authorities are on such matters, if the race organisers didn't get prior authorisation/permission I would expect that they could be in line for some hefty penalties. Skullie

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Whitegold, adding a solute to a solvent lowers the freezing point of the system, so that usually adding a solute to wet ice at 0C ambient temp will melt it, as the freezing point becomes, say -2C. This is known as 'depression of freezing point', for obvious reasons. Adding a solute to a solvent also raises it's boiling point, BTW.

In addition to this effect and the 'draining' process described by telford_mike (of which I for one had never heard), some solute/systems absorb energy as dissolution proceeds (the reverse is usually true); ammonium nitrate is one such. This means that bunging amm nitrate onto wet snow could act to reduce the temp of surrounding wet snow, freezing it and making more snow (or more likely ice).

All sounds a bit crude and haphazard, but I presume that it works. Shame about filling the water supply with amm nitrate but hey! we're talking about money and Switzerland here.

A bit like adding salt and water to your ice bucket to get the champers colder quicker.

You know it makes sense.

Helen Beaumont, exactly like that but without, crucially, the champers; an example of an endothermic process lowering the temperature. Salt is also sprinkled on ice (for example on the pavement) to melt it, which is an example of the deression of freezing point.

Otherwise you'll just go on seeing the one name:

I,ll scan the swiss papers if I get ime today. It was a big deal on the news lastnight.

A snowHead

A bit more news from Swiss papers this morning

http://www.espace.ch/artikel_308267.html

A snowHead

Bit more today about this

1.4 tons of chemicals used !!

http://www.espace.ch/artikel_310865.html

Well, the person's real but it's just a made up name, see?

stanton, 1.4 tons is not very much in terms of volume probably only about a pallet full.

Note that thios doesn't mean I approve just that I understand why perhaps people at the time didn't think about it

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D G Orf, 1.4 tons isn't much, but I bet that whoever sanctioned it knew exactly what they were doing!

Anyway, snowHeads is much more fun if you do.

richmond,I agree about whoever sanctioned it knowing what they were doing, I suspect that whoever actually spread the stuff probably didn't, last year they were using the Swiss army to do a lot of piste prep

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The knives will be out then.

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I watched military types preparing the piste on the Lauberhorne adjacent to the bumps last year. It seemed to consist mainly of standing around smoking and watching nervous skiiers. Mind you, I was standing around watching them standing around smoking and watching us.

Do they usually use the Army tp prepare for the downhill?

After all it is free

Brian T, from I've heard of the Swiss army, it seems to spend most of it's time standing around smoking. The rest is apparently spent sitting around drinking coffee fortified with spirits. No wonder they seem keen to retain national service.

richmond, that's what soldiers do when there isn't a war on. The Swiss aren't sufficiently bellicose.

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I asked a ski instructor last week what the local view of this was. He said, "Well the Farmers you know are very happy: the grass is now 1m tall"

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LAUBERHORNRENNEN (Wengen) Piste Illegally Prepared

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