Restraining bars

[Gleb]

How often do you put the restraining bar on the lifts down?

[kjl]

I do when they have footrests, or if I'm going to do a major backpack-involved gear-fiddle, or if there are Powder Pandas I have to escort to the top of the lift ;)

[Gleb]

i totally forgot the footrest thing. I hate when i get off a lift and find out that my circulation is cut off.

[Guest dragonsword5]

I usually put mine down...I like to lean over and just rest my arms on it for the short trip up the mountain. Though I also hate not having the foot rests ::cough:: Mountain Creek ::cough::

Worst thing about the old heavy foot rest type bars...they come down fast...and hard. I'm so happy I had my helmet on when my friend brought down the bar. I still saw stars but boy did that save my head.

Btw...what do you prefer? Gondola or ski lift?

[Daneille]

I really like the ones with a foot rest, otherwise I don't like them.

Daneille

[Mike T]

I really like the ones with a foot rest, otherwise I don't like them.

Same here. Nothing like an old footrest-less two-seater to put my feet asleep ::cough:: RAinbow @ Bachelor

[Gleb]

Worst thing about the old heavy foot rest type bars...they come down fast...and hard. I'm so happy I had my helmet on when my friend brought down the bar. I still saw stars but boy did that save my head.

Btw...what do you prefer? Gondola or ski lift?

Ive had the bars come down on my head countless times. Good thing i never go with my helmet. One time it wasn't till half way up when someone decided to put the bar down when i was leaning forward:eek:

I havent been on a gondola for 10 years, my first time skiing and last time time for 7 years or so. I would prolly like them more because they're warmer.

[skategoat]

I'm scratching my head on this one. Why wouldn't you put it down? Uncool? Does it ruin the view of your feet?

Gleb, you never go without a helmet but you don't put your safety bar down?

[Gleb]

well, i believe that putting down the restraining bar is unneccesary because all chairs are designed so that if they are going full speed and then come to a sudden stop, no one will fall out. that is unless someone is leaning forward very far. The chair will tilt back and forth to keep whater is on the chair from falling off.

I wear my helmet because of the icy conditions out here and its saved me countless times from serious injury.

[B18C1]

I usually put it down because it takes about 2 seconds and a half, it's comfortable, and I guess it can be useful in case something happens. There's no big difference wheter you put it down or not, unless you're with children in the chair.

Edit :: Woohoo! Groomer Groomet..

[NateW]

I do not put the bar down because I am afraid my friends will think I'm a sissy.

[NateW]

Just kidding.

[LeeW]

I do work as an electrician for ski lift construction. I do get nervous when the bullwheel stop as in e-stop and it'd yank the line. so no thanks, i rather remain intact and hanging my arms as armrest on my lift as i enjoy the view of the mountain.

[Galen]

well, i believe that putting down the restraining bar is unneccesary because all chairs are designed so that if they are going full speed and then come to a sudden stop, no one will fall out. that is unless someone is leaning forward very far. The chair will tilt back and forth to keep whater is on the chair from falling off.

....except that is what happened a year or two ago at bachelor, dumped the whole lot off the chair. Cant remeber if it was 4 or 6 people.

[surfinsmiley]

I never actually put it down but some of the ones I`ve been on are all automatic, can be painfull when it is built for people about five foot tall, there`s just not enough room for all my long legs, arms and boards, something always seems to get squashed:smashfrea

I rode a 5.5 kilometre long gondola last week, I was thinking at the time how happy I was it wasn`t a chair.

[tufty]

well, i believe that putting down the restraining bar is unneccesary because all chairs are designed so that if they are going full speed and then come to a sudden stop, no one will fall out. that is unless someone is leaning forward very far. The chair will tilt back and forth to keep whater is on the chair from falling off.

You _believe_ that it is unnecessary.

Having seen a child fall off of our lift, 8-10m onto hardpack[1][2], earlier this season after lifting the bar to adjust leg placement, I'd say you are dead wrong. If there was no need for a safety bar, there wouldn't be one.

Let's look at what constitutes a chairlift...

there's the chair, which is suspended from the cable. The suspension articulates both side to side and front to back, and in theory allows the chair to swing just enough but not too much. However, it has to be damp out the swinging otherwise there would be pools of puke under the entire length of the lift. This damping is accomplished by adjusting the suspension, and sometimes the adjustment slips, either due to worn pieces, cold, or other reasons. The fact that the adjustment has slipped is _not_ obvious to the operator - The lift I work on has one chair that we have to adjust twice daily and the only reason we know about it is because it nearly broke my frickin' leg when I got on, it de-adjusts to a completely rigid state.

The chairs quite often have seat covers on them to make the ride more comfortable. They can also make the chair more slippery.

Next, we have a cable, running over a bunch of pulleys. Depending on the loading of the lift, this rises and falls.

Then we have the main tractor and return pulleys, bastarding great things which can not allow the cable to slip. Either the tractor or return pulley is on a moving base that takes up the slack in the cable as it stretches / loads. the tractor pulley is generally equipped with a big-ass emergency brake.

Then there's the whole drive mechanism, usually an electric motor with a diesel backup. There is a second "normal usage" brake in the drive mechanism.

So, there's the machanism. Now, what happens when it's running?

Let's assume my lift, which is a "pince fixe" lift (i.e. the chairs don't come off the cable). It runs at 2.5 m/s full speed and 1.5m/s slow speed. There are 3 ways in which the operator can stop the lift:

1: Electric stop. This doesn't touch the brakes, instead powers up the phases of the motor to stop it dead. We don't generally use this unless we're doing "precision" positioning work (for example moving the chairs about) as it run a risk of burning out the motor

2: Normal stop. Turns off the motor, and activates the normal brake. This stops the lift fairly gently (roughly 5 to 7m of movement before a complete stop).

3: Emergency stop. Turns off the motor and activates both brakes. This stops the lift fairly rapidly (roughly 3 to 4 metres of movement before complete stop), takes an age to rearm, and generally scares people.

There is another stop, which is the failure mode stop. If the electromechanicals detect that the lift is running too fast, slipping backwards, the gearbox is failing, the cable has overstretched, etc, it slams _everything_. This is basically an emergency stop plus an electric stop, and it stops the lift _dead_. If you're on the lift when this happens, it's terrifying.

This is all pretty much common to all chairlifts, the only real difference between "pince fixe" and "debrayable" lifts apart from the mechanics that hold the chair to the line and the the fact that the chairs come off the line on a debrayable is that a debrayable runs at much higher speeds.

So, your assertion as to the fact it's safe to leave the bar up:

You have an interface between bum and chair that is of an unknown coefficient of friction depending on chair cover, trouser type, and weather condition.

You have a chair that may or may not swing in the way it is intended to. Even in the best case, it doesn't swing completely freely, so there will always be a certain tendency for your trousers to slide on the seat when the lift stops.

When the lift stops, the cable "bounces". Depending on where a chair is on the line, how loaded the line is, and a host of other factors, this may coincide with the forward or rearward swing of the chair, and will affect the coefficient of friction between chair and trouser either in a negative or positive way.

A failure mode stop is immediate, and an emergency stop is near-immediate.

This is why we stop our lift if anyone gets near the first pylon without having pulled down the bar. And having looked on in horror as a child plummeted from the lift, knowing full well that I could do absolutely nothing, I'd ask you, for the good of the mental health of your local lifties, to pull down the bar.

Simon

[1] Without the lift stopping, even

[2] He got off lightly, 2 smashed wrists, one broken leg and a few broken ribs.

[nils]

i'm still astounished that in the country of lawyers there is not bars on every lift!! :)

There is no single lift in the alps without bars and footrests! Even in remote small resorts with lifts from the 60's they have bars and footrests! I remember riding the buttermilk lift with anxiety at the SES... brrrr ( there must be laywers watching the lift with binoculars during daylight just in case no?)..

Why wear a helmet and not use bars?

Nils

[Baka Dasai]

Btw...what do you prefer? Gondola or ski lift?

I don't like gondolas. They seem slower, what with all the mucking about taking off your board and walking up steps, and then doing the reverse at the top.

On chairs I always put the safety bar down. I don't think it actually is safer, but it feels safer. IOW, it's like helmets - you consume the extra safety by taking more risks (leaning out over the bar, fiddling with backpacks etc).

Actually, I believe there's some numbers to show that chairs with safety bars are more dangerous - people are more likely to fall off the chair when putting the bar down or lifting it up than if there was no bar to worry about at all, and people also get caught up in the bar when unloading.

So in litigation-conscious America I imagine the lawyers are telling the resorts to not install safety bars.

[nils]

not sure baka:

if it was safer they would remove the bars everywhere worldwide no?

I think bars are way more safers to have on a lift than no bars!.. The risk of getting caught with the bar is ridiculy small compare to the injuries you would get from falling 30 feet! You cannot really take risks with bars like with helmets going faster: the bar prevents you from falling whatever you try!

no?

Nils

[Baka Dasai]

if it was safer they would remove the bars everywhere worldwide no?

Well, it takes a while for information to filter out, especially when the conclusions from that information are counter-intuitive, such as a safety measure making something more dangerous.

The risk of getting caught with the bar is ridiculy small compare to the injuries you would get from falling 30 feet!

That's not the relevant comparison. You have to compare the death/injury resulting from bar-related falls and accidents with non-bar related falls and accidents. And as for the risk of getting caught by the bar - I've seen that happen dozens of times in my life (clothes etc getting caught while unloading) but I've never seen somebody fall from a chair. There's also the risk of being clonked on the head by the bar as it's being lowered or raised. I've seen that happen a few times.

You cannot really take risks with bars like with helmets going faster: the bar prevents you from falling whatever you try!

People fall off the lift during the process of raising and lowering the bar. If they didn't have to go through that process they'd be less likely to fall off.

I take a perverse pleasure in watching safety measures fail, even as I usually apply those same safety measures myself. The really contentious one is <a href="http://www.geog.ucl.ac.uk/~jadams/PDFs/failure%20of%20seatbelt%20legislation.pdf">seat belts</a>.

[scotts.Scheinman]

i personally dont care but my brother always wants the bar down

[tufty]

People fall off the lift during the process of raising and lowering the bar. If they didn't have to go through that process they'd be less likely to fall off.

Whe people fall off lowering or raising the bar, they are generally not high up and not over hardpack. Here's 4 season's worth of driving a chairlift:

Departure end : I have _never_ seen anyone fall off a lift due to lowering the bar. Fall off due to having their sticks in the wrong place, being complete tools, etc, yes. But never due to lowering the bar.

Arrival end : I've never seen anyone fall when raising the bar. I've seen them fall on debarking due to raising the bar too late, go round the pulley and cause an emergency stop due to not raising it at all, etc. I have _once_ seen someone get caught on the bar. I have seen hundreds of incidents of people getting caught on the rest of the chair, and I only man the arrival end of the lift for an hour a day, at lunchtime when there's nobody about.

What I have seen is an incident of a small child falling 30+ feet onto hardpack due to lifting the bar en route. I never want to see it again.

Basically, and please don't take this personally, but I think you're very, very wrong.

[edit]According the the Syndicat Nationale des Telepheriques de France http://www.sntf.org for the season 2004/2005 there were 15 serious accidents for 702,000,000 passages in the whole of France. At least one of those was a small child trapped and subsequently killed in a 'rolling carpet' travelator that resulted in serious legal consequences for the people responsible (they had turned off the security mechanisms as it kept stopping) and one other was an English child at Chatel who fell 10m from a chairlift onto a grooming machine 25m from the departure. I can't find a full breakdown of accidents, those two were two I remember from last season. Not sure if the helicopter full of pisteurs killed at Chamonix last year in colliion with a lift cable is included in the number.

Here's a video of the typical chairlift accident : http://www.zone-videos.net/video-1034-telesiege-accident.html

And here's one of what you do not want to see. http://tufty.ath.cx/~simon/chairlift.wmv

Simon

[big mario]

Dont even have 'em at loveland, so I don't even think about it.

mario

[nils]

simon i agree...

anyway since most of the lift systems are provided by french ( pomagalski ) or austrian, german or swiss companies, there is good chances bars make it to the US finally after some time !

[Gleb]

too me, it seems that people only really fall off as a consequence of their own actions. For example, the incident where the kid fell into a grooming machine. As tragic as it is, most likely the child was leaning to far forward to observe the groomer. Or when the child fell 10meters onto hardpack without the lift stopping, well that again most likely resulted from the child leaning too far over. Usually when i'm on a lift with children, they put the bar down so they can lean on it.

Most chair lifts ive been on are slanted back so its nearly impossible to slip off, even if the lift comes to a dead stop. I always lean all the way back to get comfortable instead of leaning forward. Usually the fabric is foam which usually has a reletivly high coefficient of friction against my pants compared to nylon.