Snow Ski

Posted by PITHOCRATES - February 26th, 2014

Technology 101

Gravity and Speed keeps a Skier’s Skies in contact with the Mountain and Provides Control

The Winter Olympics have come and gone.  And if you are a big fan of the Winter Olympics you probably were somewhat disappointed.  Especially if you’re a fan of alpine skiing.  Because it was just too warm.  They have the Olympics in February for a reason.  Because February is a very cold month.  And the mountains have a couple of months of snow on them by February.  Allowing the snow groomers to do their magic.  And turn those mountains into hard sheets of ice.

Yes, ski racers ski on ice.  Not snow.  If you ever skied on a mountain where there was once an Olympic downhill racecourse you will see very steep slopes of ice.  If you ski slowly across the fall line of the slope at the top of the mountain you will slide further down hill than you ski across the slope.  With your ski edges sliding across the ice.  And about the only thing that will stop your ‘free-fall’ slide down that steep ice-covered slope is the loose snow on the sides of the slope.  But if you travel down this same slope at speeds around 70 mph your skies will carve into that ice.  Giving you great control.  If you have the skills of an Olympic downhill skier, that is.  If you’re not as skilled as a downhill racer then you shouldn’t try this.  Because if you fall at speed up there you can do some real damage to yourself.

Downhill skiers love that speed, though.  And will give themselves up completely to gravity.  And let it pull them down these steep, sheets of ice at breakneck speeds.  With nothing to keep them from flying off the mountain and breaking their necks but their skies.  As gravity and speed keeps their skies in contact with the mountain.  Giving them control to stay on their skies.  And carve their way down the mountain.  Literally.

When a Skier leans over on a Ski the Curved Edge of the Ski carves into the Snow or Ice and Turns the Skier

In alpine skiing there are 5 different races.  The downhill.  The super giant slalom (known as super G).  Giant slalom.  Slalom.  And combined.  Which is a combination of two ski races.  One downhill race and one slalom race.  The downhill is the straightest and fastest down the mountain.  The super G is a little more ‘turny’ and a little slower than downhill.   The giant slalom is more ‘turny’ and slower than Super G.  And the slalom is more ‘turny’ and slower than giant slalom.  The downhill is all about speed.  The turns aren’t that sharp.  While the slalom is all about the turns.  With speeds that aren’t that fast.

Each of these races requires different types of skies.  The downhill race needs long skies that will absorb the bumps of rough terrain without bouncing off.  And speed is more important than turning.  While slalom skies need shorter skies to make sharper turns.  And because they are shorter they may come off the snow as they bounce over rough terrain.  So they match the ski to the race.  And because of the requirements of downhill racing these skies are available only to professional skiers.  You will not find them in any sporting goods store.  As amateur and recreational skiers could not control them safely on steep sheets of ice at downhill speeds.

If you look at a ski lying on the ground you will see that it is narrower at the center where it attaches to the ski boot and wider at the tip and the tail.  And it goes from wide to narrow to wide in a continuous curve.  This curve is the side-cut radius.  This is what turns the ski.  When a skier leans over on the ski the curved edge of the ski carves into the snow or ice.  Turning the skier.  The more curved the side-cut radius the tighter turns it will allow.  So slalom skies are more curved in the side-cut radius than downhill skills.

The Winter Olympics are in February so Ski Racers can ski on Mountains that are Hard Sheets of Ice

Looking at a ski resting on a hard surface you will notice something else.  The center of the ski will be off that hard surface.  While the tip and the tail will be in contact with that surface.  This arch—or camber—of the ski helps to force the ski into contact with the snow when you place weight onto them.  Especially the steel edges when turning.  When a skier carves a turn he or she will literally carve that turn into the ice of the mountain.  In a clean turn the tail of the ski will follow the same groove carved by the tip.  With a minimum loss of speed.  If the tail slides out of this groove and carve its own groove it will slow the skier down.  And in downhill skiing where first and second place can be separated by one one-hundredth of a second one slight skid in a turn can be the difference between winning and coming in second.

As downhill skiers leave the starting gate they will take a couple of pushes with their ski poles to help gravity pull them down faster and then assume a tuck position.  To decrease their air drag.  As they approach a gate they will turn by leaning on their edges.  The sharper the turn the more they will lean onto to their edges to carve a tighter turn.  And the more speed they will lose.  Which is why racers will look for the best ‘line’ down the mountain.  One that minimizes sharp turns.  Once out of the turn they will release their edges and ski on the bottom of their skies.  Gaining speed.  They will absorb the rough terrain in their legs.  And fight the compression of the g-forces with their legs.  They lean into turns, release their edges, ride on the bottoms of their skis in the flats, lean on their edges, etc.  At speeds around 70 mph.  As they carve their way down a mountain of ice to cross the finish line in the shortest amount of time.

As spring approaches the ski resorts warm up.  Some people love this.  Spring skiing conditions.  Loose snow on the slopes but warming weather.  So warm that a lot of ski areas will have events like bikini races or lingerie races where girls will ski down the mountain half naked in the warming weather.  It can be a real party on the slopes.  But the skiing will be horrible.  The snow will be melting.  It will be wet.  Granular.  Pushed up into piles.  Making it easy to catch an edge and fall.  And difficult to build up any speed.  Which is why the Winter Olympics are in February.  In the coldest part of winter.  With a lot of snow frozen on the mountain.  And they typically don’t hold them in subtropical climates.  Where the average temperature in February is 50 degrees Fahrenheit.  Like in Sochi, Russia.  Where skiers had to deal with spring skiing conditions.  And varying conditions.  As the snow at the top of a run was different from the snow at the bottom of the run.  Despite the amount of chemicals they put on the snow to try and raise the melting temperature of the snow.  Making these Winter Games not as good as past Winter Games.  If you’re a fan of alpine skiing, that is.  Or prefer seeing cold winter vistas at the Winter Olympics.  And not people lying on the bare grass catching a suntan.

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Your Odds of Dying or getting Seriously Injured Skiing/Snowboarding are about the same as Dying in a Mass Shooting

Posted by PITHOCRATES - February 24th, 2013

Week in Review

The first time I skied on a mountain I was pretty nervous.  I had only just begun to ski.  I was still snow plowing my way down the slopes.  But my friends were going to a great ski resort.  I didn’t want to miss out on a good time.  When we arrived and bought our lift tickets there was a newspaper clipping taped to the window.  Earlier that week a girl fell out of a chairlift and died.  Making me even more nervous.

It was cold.  Very cold.  The sun was melting the snow a little in the day.  And it froze at night.  Except when we got there.  The clouds never broke when we were there.  So the slopes were sheer hard ice all day long.  As I snow-plowed back and forth across the mountain I slid sideways down the fall line.  As I stopped to rest an advanced skier stopped by me.  He remarked how bad the conditions were.  The slopes were littered with death cookies.  Frozen chunks of ice that didn’t move when a ski hit them.  Making me even more nervous.  On the next day the winds were so bad they closed part of the mountain.  Because the mid-station served that side of the mountain I couldn’t get off there.  Something I didn’t know until after getting on the lift.  I had to take the lift to the top of the mountain.  Where you could take some runs down that kept you off the closed side of the mountain.  Making for a very long and tiring snow-plow down.  Suffering the early stages of frostbite, aching muscles and some bruising from some falls and collisions I left the mountain that day and made it home alive.  Despite a few close calls.

When you’re young you do stupid things.  And take risks.  Like skiing on a mountain when you’re barely a beginner.  Skiing is dangerous.  People die skiing every year.  Including kids (see First picture of tragic 13-year-old schoolgirl who died in ski lift accident on school trip to Italy as friends pay tribute to ‘bubbly and popular’ teenager by Hannah Roberts posted 2/24/2013 on the Daily Mail).

Tragedy had struck on the first lift of the day, moments after the teenager had put on her skis.

According to newly-emerged details, the schoolgirl slid from the chair after accidentally sitting in the wrong seat of the four-man chairlift.

Investigators told the La Stampa newspaper: ‘She didn’t end up sitting in her assigned seat, perhaps as a joke or because she lost her balance. In any case she ended up sitting in the arms of a school friend.

‘Because of this the safety bar didnt go all the way down, so at the first tremour of the lift, she slid and fell’.

The schoolgirl’s injuries were compounded by the fact that she fell not onto fresh snow but onto a stream in which there lay several rocks, it has now emerged.

A terrible tragedy.  What makes it so tragic is that it seemed so harmless.  Just goofing around on a chairlift.  But how quickly things changed from silly fun to horrific tragedy.  Anyone who has ever skied probably did a lot of stupid things that only dumb luck kept them from hurting themselves.  Or killing themselves.  According to the National Ski Areas Association about 42 people die on average skiing and snowboarding each year in the U.S.  With another 45 suffering paralysis, serious head and other serious injuries.  But we don’t hear a lot about this horrific toll of death and suffering.

According to the Washington Post approximately 84 people died in mass shootings in the U.S. in 2012.  Including the great tragedy in the theater in Aurora, Colorado.  And the great tragedy at the school in Newtown, Connecticut.  The media does not stop talking about these 84 deaths.  And neither do the liberal Democrats pushing for gun control.  Who want nothing less than a total ban on guns.  Even if it saves only one life.  Yet not one of them is calling for a total ban on skiing and snowboarding.  Which will save more than one life.  In fact, we know the number of lives such a ban would save.  It would save about 42 people on average a year.  (As well as preventing another 45 from suffering paralysis, serious head and other serious injuries.)  Which is more than one.  Yet there is no such push for a skiing and snowboarding ban.  Why?  Young people do most of the skiing and snowboarding.  And liberal Democrats don’t want to piss them off by taking away something the vast majority of them enjoy and do responsibly.  While giving no such courtesy to gun owners.  The vast majority of which are responsible.

Why the double standard?  If they don’t care about the loss of life on the slopes then they can’t care about the loss of life from these mass shootings.  Meaning that they want to take away those guns for some other reason.

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The Swiss install a Solar-Powered Ski Lift in Tenna to use During the Short Gray Days of Winter

Posted by PITHOCRATES - February 5th, 2012

Week in Review

A tiny little town in Switzerland, Tenna, has a small ski resort with one T-bar ski lift.  The kind where they pull you uphill while you stand on your skis.  With the lift between your legs and the ‘T’ behind your upper thighs where they join the buttocks.  It’s not the most comfortable way to the top.  But it sure beats cross-country skiing uphill to alpine-ski downhill.  Or the dreaded tow rope.  Where you pull your weight uphill by holding on to the rope as it pulls you uphill.

This ski lift was wearing out.  And it was the only one in the valley.  But what is winter in a Swiss valley without skiing?  Long, cold and gray.  So the people of Terra saved that T-bar lift.  To make those short gray days more bearable (see Tiny Swiss town builds the world’s first solar-powered ski lift by Adventure Journal posted 2/2/2012 on GrindTV).

The Tenna lift generates 90,000 kilowatt hours a year, or three times the juice needed to run the lift, and the extra power goes back into the grid, which makes money for the town, which can pay residents back…

At $1.5 million, the project wasn’t cheap, but considering the cost of a new or updated lift anyway, plus the open skies above most ski lift pathways, it’s a no-brainer to use that area to offset the energy use. Other resorts might not gain 300 percent efficiency as in Tenna…

If you follow the link you’ll see a sunny picture of the lift.  With a lot of clouds in the sky.  On a sunny day.  So it’s just not night time that’s a problem with solar power.  It’s the clouds, too.  That’s why solar power has such a low capacity factor.  The labeled output for those solar panels may be 90,000 kilowatt hours a year.  But after you apply a 25% capacity factor to account for when the sun doesn’t shine, that’s only 22,500 kilowatt hours a year.  Which means there’s a good chance that there will be times when skiers won’t reach the top of the mountain.  Luckily for them, though, it’s a T-bar lift.  Where their feet will always be touching the ground on the ride up.  So they can always ski back to their car when the lift stops working.  And start up their good old reliable internal combustion engine to drive back home.

Seems like a lot of money to spend for a part-time ski lift.

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