47 replies to this topic

[Razvan]

2milehi, on 23 October 2011 - 08:50 AM, said:

To be an astronaut don't you need a vehicle that will get you into space?

Nope. All you need is a bunch of black suits&ties running around you with clipboards, while you pretend training in your white suit&hoses, eventually in a heated pool simulating the harsh conditions of space, trying to make a case for increasing NASA space exploration budget while hitching rides on Soyuz or, why not, Romanian peroxide rockets.
(Seriously, check out https://www.arcaspace.com/en/home.php)

More seriously, NASA budget is well-spent and on the right track. Their website beats the websites of ESA and ROSCOSMOS by far - not to mention China National Space Administration's.
Their level of Java and PHP programming is light years ahead. They are pursuing these technologies even further, not because they are easy but because they are hard. I have achieved the goal, before this debate is out, of viewing online one of their Flash presentations about exploration of the moon, and returned my browser safely to skilifts.org.

This post has been edited by Razvan: 23 October 2011 - 02:11 PM

[Don Coyote®]

2milehi, on 23 October 2011 - 08:50 AM, said:

To be an astronaut don't you need a vehicle that will get you into space?

Just disable the Enertia Damper on your High-Speed Quad, engage the Hyperdrive... and see how high you can get when you clear the top wheel!!!

[mthornton]

Ski-lift load-testing, using live domestic sheep as the test mass.

A few years back we had the task of performing the required 5-year load-test on our Summit chair, which was built new in 2003. For chairlift load-tests we typically use cardboard boxes, lined with large plastic garbage-bags, and then filled with water pumped using our snow-making system. Our pump-house is at an elevation of 1140m, and to get water to the bottom of summit-chair, it has to go over a hump at 2165m, for a total head of 1025m (3362'). It became my task to calculate the dollar cost for the electricity required to run 2 of our big pumps in high-pressure mode (2 x 500 hp pumps in series) for long enough to fill the system. Well it ain't cheap.

At the time we had a new mechanic, straight out of the New Zealand army, and a common lunchroom topic of discussion was the sexual preferences of young Kiwi men, and their fine nation's infatuation with sheep. It occurred to me that simply buying a suitable number of live sheep for the load-test, would be less expensive than pumping the water. (sheep are cheep!)

Their average mass is exactly what we need, all we would need to do is order up a few hundred sheep, get 4 sheep loaded per chair, and get on with the load-test. It is possible that a few would panic and leap to certain death, but the others would see and learn, and settle-down for the ride. BTW, it is also typical to loose a couple of water-filled boxes during a load-test.

The last test we typically perform is the "ALL BRAKES" test, during which the lift experiences it's maximum deceleration rate. We save this for last because we typically loose quite a few water-filled boxes, and we would expect to loose quite a few more sheep... oh well, it's the end of the test.

After a normal load-test, we typically stab the cardboard boxes with ski-poles, and let them drain for a lap... we would do the same with the sheep, afterwords neatly loading their deflated and empty shells into the back of the pickup. Fire up the barbie! Time for a feast! Come celebrate the usefulness of sheep!

A few sheep may escape, becoming the breeding stock for wild, on-hill feral-sheep, providing the mass required for future load-tests. And that kiwi mechanic (still with us) would be a happy man.

[Bogong]

Mt Thornton, I admire you deranged, but possibly brilliant, thought process.

So why didn't you go ahead with this visionary plan?

[Razvan]

Stab me, mate.

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This post has been edited by Razvan: 28 October 2011 - 12:21 PM

[Don Coyote®]

Who's gon'na bring the potato salad?

[Emax]

Don Coyote®, on 28 October 2011 - 02:57 PM, said:

Who's gon'na bring the potato salad?

I don't get it.

[Emax]

Razvan, on 28 October 2011 - 12:20 PM, said:

Stab me, mate.

Man! That would be some ride! How would one explain at the emergency room?

[Don Coyote®]

Emax, on 29 October 2011 - 05:42 AM, said:

I don't get it.

Well there HAS to be potato salad at a sheep barbeque of THIS magnitude!!!

[mthornton]

Yesterday we received a friendly bill from BC Hydro, stating that over the past 62 days my house has consumed 740 kWh ($62). We don't have a gas connection, but we do have a wood stove.
So in 62 days my house uses enough energy to run our 4 main snow-making pumps, plus 2 of our 3 air-compressors (typical), for about 16.5 minutes (actually a bit less, because they run at a power-factor of about 90%, so there is some heat-loss in the distribution transformer... also our cost.). We also run some fan-guns, and a number of auxiliary pumps.
We now almost have 1 major run completed (snow-making), and a second will be done by the end of next week, after which we will open for ski-racer training. By the time all snowmaking is completed in mid January, SM will have consumed about 6,000,000 kWh, worth about $350,000. And this is not a big ski-hill.
Our lifts don't use anywhere near as much energy as snow-making. I've measured and studied this to death, and the lifts require almost as much energy to heat the ski-lift machinery so it runs well, as it does to make them go round. This is especially true of the detachables.
It is my job to keep all this energy flowing... so I can get paid... so I can pay my $62 bi-monthly household electricity bill.

[Emax]

Mitch makes a good point.

It's interesting that the common lay-understanding of electrical power has it that the lift motors are the main consumers at a resort. I usually point out that 1HP = 1kw (roughly - efficiencies taken into account). A 400 HP motor running at 75% capacity (typical for a lift) therefore consumes 300 kW per hour ($15 per hour at our rates). By comparison, a 10 kW unit heater (again, typical) is equal to a 10 HP motor. Add up all the heat-producing equipment in and around the lifts and the power required to run them usually exceeds that needed to turn the lifts. We have found that during our night skiing operations, it costs more to light the hill than to run the lightly-loaded lift.

The production of fake snow is in its own universe with respect to power cost. Our small resort uses 1200 hp for pumps alone. I have to wonder if it's really worth the investment.

This post has been edited by Emax: 30 October 2011 - 06:50 AM

[Don Coyote®]

I've been curious for some time concerning the difference (or comparison) of power consumption rates between the old 38hp electric motor on my T-Bar and the new 23hp gas engine that powers it, now.

I only use "Premium" gas in my small engines. My lift will run for an hour on a little less than a gallon of fuel. (I round up to a full gallon..... actually, it might run for six hours on five gallons..... but I just round up). So if I'm paying $4.00 a gallon, it costs $4.00 an hour to run.


.....That's not bad. (And we don't have lights or snowmaking).


So by YOUR math..... my old electric motor might cost $1.50 an hour to turn my T-Bar?


I guess If I can use my lift for five hours a day... that's still far less than the cost of a single lift-ticket. And that cost might be consumed by about a dozen people using the lift, that day. That's not quite enough of an incentive to pay to run a new 440 line out to the shack. And besides..... the antique electric control panel scares the Hell out of me. I couldn't imagine it could ever be put back into service, safely.

Although,..... we are considering adding to the expense by adding some small gas generators scattered around the hills to power some bright landscaping lights. (It would be GREAT to get in some night-boarding at the Nob).

This post has been edited by Don Coyote®: 30 October 2011 - 08:11 AM

[Emax]

Don Coyote®, on 30 October 2011 - 08:02 AM, said:

I've been curious for some time concerning the difference (or comparison) of power consumption rates between the old 38hp electric motor on my T-Bar and the new 23hp gas engine that powers it, now.

I only use "Premium" gas in my small engines. My lift will run for an hour on a little less than a gallon of fuel. (I round up to a full gallon..... actually, it might run for six hours on five gallons..... but I just round up). So if I'm paying $4.00 a gallon, it costs $4.00 an hour to run.


.....That's not bad. (And we don't have lights or snowmaking).


So by YOUR math..... my old electric motor might cost $1.50 an hour to turn my T-Bar?


I guess If I can use my lift for five hours a day... that's still far less than the cost of a single lift-ticket. And that cost might be consumed by about a dozen people using the lift, that day. That's not quite enough of an incentive to pay to run a new 440 line out to the shack. And besides..... the antique electric control panel scares the Hell out of me. I couldn't imagine it could ever be put back into service, safely.

Although,..... we are considering some small gas generators scattered around the hills to power some bright landscaping lights.

No. First, I've never seen a motor data plate claiming 38 HP - but that's not the point. The data plate information states what the motor CAN produce without overheating - this does not mean that it produces the full horsepower when loaded to less than its maximum applied load. Motors draw current in proportion to the actual load that is applied - just as your gas engine consumes fuel at a rate proportional to the load you apply to it.

[mthornton]

Don Coyote®, on 30 October 2011 - 08:02 AM, said:

... my T-Bar and the new 23hp gas engine that powers it, now.
... the antique electric control panel scares the Hell out of me. I couldn't imagine it could ever be put back into service, safely.

Gasoline scares the Hell out of me...., but hey, I'm an electrician.
On the other-hand a gasoline lift has the distinct advantage of 100% burning, without leaving any trace of evidence, a failed installation. That's good, I guess!
Good quality steel-braided flexible fuel-lines and a tank-installed gas shutoff solenoid are cheap enough I suppose.

Electric
If you suspect your existing electric starter is junk, then it probably is.
A VFD variable-speed electric drive for a surface-lift is a very beautiful thing.... you can slow it down to load the little kiddies!
Lets assume your T-bar accelerating load requires torque that can be supplied by your 30 HP electric induction motor (not wound-rotor). Rule of thumb is double the drive size (for a small VFD) to guarantee no current-limiting of the drive at breakaway.
A suitable 60 HP VFD 480V drive http://www.automatio...SLV%29/GS3-4060
costs about $3000, double that to install it, double that again for the engineering cert. and $12k-$15k would be a good starting round budget-number for the drive only, not including rebuilding your old electric induction motor or installing a new electrical service to code..

This post has been edited by mthornton: 30 October 2011 - 09:41 AM

[Emax]

mthornton, on 30 October 2011 - 09:37 AM, said:

Gasoline scares the Hell out of me...., but hey, I'm an electrician.
On the other-hand a gasoline lift has the distinct advantage of 100% burning, without leaving any trace of evidence, a failed installation. That's good, I guess!
Good quality steel-braided flexible fuel-lines and a tank-installed gas shutoff solenoid are cheap enough I suppose.

Electric
If you suspect your existing electric starter is junk, then it probably is.
A VFD variable-speed electric drive for a surface-lift is a very beautiful thing.... you can slow it down to load the little kiddies!
Lets assume your T-bar accelerating load requires torque that can be supplied by your 30 HP electric induction motor (not wound-rotor). Rule of thumb is double the drive size (for a small VFD) to guarantee no current-limiting of the drive at breakaway.
A suitable 60 HP VFD 480V drive http://www.automatio...SLV%29/GS3-4060
costs about $3000, double that to install it, double that again for the engineering cert. and $12k-$15k would be a good starting round budget-number for the drive only, not including rebuilding your old electric induction motor or installing a new electrical service to code..

Hey Mitch - I'm thinking that the fact that the lift is currently turning with a 23 HP gas engine suggests a much smaller AC drive (in fact, quite a bit less than 23 HP - what altitude is this thing running at?). I'm not sure, however, if the current AC drives being offered by A-D react badly to being connected to motors that are larger than their rating - even when de-tuned. I've had that problem in the past with other brands of inverters. Your thoughts?

Using a smaller inverter would take a lot of the sting out of the cost of conversion.

This post has been edited by Emax: 31 October 2011 - 01:39 PM

[mthornton]

Have you ever tried to herd a flock of ski-school in performing a load-test on T-Bar? I think it would be easier to get the same ski-school to teach a flock of sheep to ski. And the ski instructors would have an elevated chance of getting laid.... it's a win-win!

An advantage of a gasoline motor is it's ability to diliver a relatively high starting torque through a mechanical clutch.

An equivalent horsepower electric induction motor has less available starting torque, and even less again when it is asked to start a constant torque load (like a ski-lift) slow & smooth. Over-sizing the VFD drive WRT the motor is in allowance so that it can supply the higher current required during a slow start, as well as sustained slow-speed operation, without current-limiting. My experience with the AD VFD drives is that it is no problem to tell the drive it is operating a motor smaller that the HP rating of the drive. It is also reasonable to auto-tune the drive to a smaller motor, then manually tweak the current-limit and overload settings.

Of course it is not possible to ask an undersized VFD drive to supply a higher sustained current then the device is rated for, although some drives can deliver 300% during start, taking care not to trip the overload (thermal model) . Sometimes that's not quite enough current to get breakaway.

This post has been edited by mthornton: 01 November 2011 - 04:55 AM

[Don Coyote®]

mthornton, on 01 November 2011 - 04:50 AM, said:

An advantage of a gasoline motor is it's ability to diliver a relatively high starting torque through a mechanical clutch.

I just like the way it goes..... VROOM VROOM.






Curiously, my engine doesn't actually HAVE a clutch. (Maybe vicariously). My entire engine mount is a giant hinge. The linkage that engages the torque simply pulls the entire engine into a truck tire. (There is a 3-1/2 inch diameter aluminum roller mounted to the engine PTO shaft which turns the tire). When the engine is properly warm, it doesn't skip a beat in engaging all it's necessary torque to power the lift.... no matter how quickly you pull the handle back.


It's a beautiful thing.

[Don Coyote®]

We've gone from "Leap Years" to "Space Launches" to "Sheep Barbeques" to "electric to gas and back to electric conversions" in this topic.


Anyone else got any somewhat useless trivia to share?

[Razvan]

Yeah, I got one.
Although it's acronymed (do I have to flash my licentia poetica?) as BBQ, the correct full spelling is "barbecue".

[mthornton]

Barbecue is the USA spelling, Barbeque is the correct spelling in many other English speaking countries.

But hey, you can spell "table" correctly, but miss on centre, colour & cheque. My Google Chrome browser tries to auto-correct each of these properly spelled words. NBD.