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View Full Version : Would it be possible to build a rollercoaster with a ballistic section?

Mangetout
06-12-2007, 08:39 AM
I was thinking about the search for ever more aggressive and frightening fairground experiences and I reckon a good one would be if it were possible to design a rollercoaster where the carriage leaves the track completely for a moment and travels completely freely in a ballistic trajectory, before being 'caught' and reunited with the rails.

Is it even remotely possible? I'm thinking not, because I can't think of a way it could possibly take into account all variables, including acceleration caused by shifts in its own centre of mass as the passengers writhe in terror.

Jurph
06-12-2007, 09:07 AM
You could use existing data and modeling & simulation tools to figure out what a zero-gee slope looks like and put the rails on that path. Since modern coasters have "upstops" on the carriages, the best you could settle for is a descent that was so close to ballistic that the upstops and main wheels were both pressing on the rail evenly and acting only as guides. Are you talking about removing a section of that track and letting the coaster's momentum carry it onto the resumed track?

If so, you might be able to design a "basket" with flared rails that allowed for lateral and vertical error, so that the carriage goes shooting off a cliff, travels over (let's say) twenty feet of missing track, and then gets steered back into alignment by the basket before being reunited with the rails. I can envision a front car with a series of runners/rails/guide-wheels protruding from its nose, designed to mate up with such a basket and zero out the error before the car had to meet the second set of rails.

You would need an anemometer at the site of the track departure, and ideally you'd use a computer to measure the carriage's loaded mass before each run. You could even make the jump section the second or third "big thrill" of the run, and use the earlier hills to measure the car's air drag (as a function of velocity). Then send the car into the jump with a very precisely tuned velocity and hope for the best.

The big problem would be that your rear brakes would need to be able to stop the entire train almost instantly in case of a miss (and a chain drive would need to be there to reverse the carriage back up that section). Either that or the entire carriage would need built-in parachutes and floats, and the jump built over water. Also, if you were out of lateral tolerance for the basket, you'd run the risk of having a head-on collision with it and cleaving the front car in twain. :eek: The safety concerns would obviously make this a fantasy... but then I bet they said that about loops and magnetic induction coasters too. I envision a sign that says "You must sign a waiver this tall to board this ride."

Mangetout
06-12-2007, 09:11 AM
Are you talking about removing a section of that track and letting the coaster's momentum carry it onto the resumed track?Yes - I'm talking about something that would be conspicuously ballistic. The rest of your post was great and discussed some solutions I hadn't thought of.

j_sum1
06-12-2007, 09:38 AM
I think the engineering of it would be a whole lot easier if you worked with a single car rather than a series of connected cars.

You could always design something that is a fully enclosed capsule (i.e. a cage with people inside where it is impossible to wave limbs out) and shoot it into some kind of funnel.

Actually there are a lot of ways to do some kind of jump with a single capsule, but you would need some kind of dampening/shock absorption mechanism on the landing as well as a means for repositioning the car and getting it back on the track.

Mangetout
06-12-2007, 09:55 AM
You could always design something that is a fully enclosed capsule (i.e. a cage with people inside where it is impossible to wave limbs out) and shoot it into some kind of funnel.Yes, otherwise severed limbs might be an issue, but even in an enclosed capsule, body movements could cause the capsule to rotate or move a little (if everybody waves their arms from left to right simultaneously, the capsule as a whole will move left a bit, even if only momentarily).

DSYoungEsq
06-12-2007, 09:58 AM
I was thinking about the search for ever more aggressive and frightening fairground experiences and I reckon a good one would be if it were possible to design a rollercoaster where the carriage leaves the track completely for a moment and travels completely freely in a ballistic trajectory, before being 'caught' and reunited with the rails.

Is it even remotely possible? I'm thinking not, because I can't think of a way it could possibly take into account all variables, including acceleration caused by shifts in its own centre of mass as the passengers writhe in terror.
Just one word: attorneys. :eek:

Mangetout
06-12-2007, 10:23 AM
Actually, I wonder if it might actually be easier if the ballistic section was longer - it would enable the ride capsule to adjust its trajectory with steering fins or small wings.

gonzomax
06-12-2007, 10:34 AM
Problem is ageing. As mechanical parts wear the fit changes. After a while you would have problems. Good idea for a couple weeks though.

FlyingCowOfDoom
06-12-2007, 10:40 AM
Don't forget the problem of wind! You can calculate trajectories and all that, but on a particularly windy day it all goes out the window.

--FCOD

Szlater
06-12-2007, 10:53 AM
Yes, otherwise severed limbs might be an issue, but even in an enclosed capsule, body movements could cause the capsule to rotate or move a little (if everybody waves their arms from left to right simultaneously, the capsule as a whole will move left a bit, even if only momentarily).

Hard restraints, wrists and ankles. You'd probably want to provide some neck bracing or head restraint too... and some lower back support/cushioning for the landing. Gum shields might not be a bad idea.

You might also need some additional protection against rapid deceleration. I imagine that your emergency brake system, not to mention the jump itself, might exert quite a toll on the body of the passengers.

Sunspace
06-12-2007, 11:49 AM
I'm imagining a Hot Wheels jump track here, with the flared receiver section. :)

How about doing it like the ballistic trains I've read of in 1950s science fiction? You have enclosed capsules. The capsules' trajectory goes through ring-shaped electromagnets that can adjust their courses on the fly. Then there's a receiver segment that funnels them back down to the track.

SiXSwordS
06-12-2007, 12:32 PM
I'm talking about something that would be conspicuously ballistic. <snip>
It might be possible to have it look ballistic without really being so. If the track were to have a gap that was long enough to be plainly visible by passengers inside the car, but not long enough to let the rear of the car leave the track until the front was already on the other side, the engineering might be considerably more manageable.

The cars would have to be designed to help the illusion. The wheels could extend out from the car, but not far enough to be seen. It might help if they were set up on the body of the car too, so that it would feel more like you were leaving the track when the car went over a gap.

I remember a ride from an ancient amusement park where the front wheels were set back below the front seat. It was a single car and the track made sharp, almost 90º turns. Going around a corner felt like the car was going off the track because the front of the car was going beyond the track. It was fun as hell. They even had a car below one of the turns that looked like it had fallen off.

It might not be exactly what you're envisioning, but it'd be easier to get insurance.

John DiFool
06-12-2007, 12:47 PM
How about a spherical cage/capsule type thing (as already described-the inside is weighted so that the passenger section always remains upright no matter what the outside is doing) which is launched a fairly long way into something soft (net/cushion) which gently stops the capsule which then slowly rolls down to a stop? I.e. no track on the other side.

David Simmons
06-12-2007, 01:14 PM
It would be tricky and I think also unreliable. In addition to the problems already detailed there is what is called "tipoff" in the aircraft rocket launching business. When the front wheels leave the track at the gap they immediately start to fall while the rear wheels are supported. This induces an eno-over-end rotation. Even if the car has multible sets of wheels there comes a time when the front end falls and the rotation occurs. This rotation can make for interesting effects on landing.

SiXSwordS
06-12-2007, 01:25 PM
There are already "rides" where two people strap in with five-point restraints and the cage is shot into the air by what amounts to an over sized slingshot. The "riders" do go upside down, but I thought that added to the experience.

MarcusF
06-12-2007, 01:34 PM
Originally posted by SiXSwords:
There are already "rides" where two people strap in with five-point restraints and the cage is shot into the air by what amounts to an over sized slingshot. The "riders" do go upside down, but I thought that added to the experience Yup - and they're good fun - but the "capsule" is never free of the restraints, the the giant elastic bands remain attached and stop it going out of control.

Chronos
06-12-2007, 02:26 PM
It would be tricky and I think also unreliable. In addition to the problems already detailed there is what is called "tipoff" in the aircraft rocket launching business. When the front wheels leave the track at the gap they immediately start to fall while the rear wheels are supported. This induces an eno-over-end rotation. Even if the car has multible sets of wheels there comes a time when the front end falls and the rotation occurs. This rotation can make for interesting effects on landing.I think you could get around this by going ballistic before you leave the track: That is, make the preceding section of track a parabola of the appropriate dimensions. You'd probably also want to make the receiving track osculate closely to the same parabola.

You probably also wouldn't want a railroad-type track, like with most coasters. Some roller coasters have tired wheels on the cars, and a half-pipe track (Disaster Transport, formerly Avalanche Run, at Cedar Point would be an example). I suspect that this design would be better suited for such a coaster, since it would considerably simplify the design of the catching funnel.

And finally, of course, the ride would have to be thoroughly tested for wind tolerance, and closed whenever the wind came within some safety factor of that maximum (or threatened to come within that safety factor).

iamthewalrus(:3=
06-12-2007, 03:42 PM
How about doing it like the ballistic trains I've read of in 1950s science fiction? You have enclosed capsules. The capsules' trajectory goes through ring-shaped electromagnets that can adjust their courses on the fly. Then there's a receiver segment that funnels them back down to the track.There are practicality issues with large electromagnets: most theme-park attendees are likely to be carrying personal electronics that aren't too happy about moving through a magnetic field strong enough to push a rollercoaster car around.

Also, there was a recent story about a rollercoaster car that got stuck upside down when the power was interrupted and the emergency brakes locked down. What does the ballistic coaster do when the power goes out?

Sunspace
06-12-2007, 04:02 PM
There are practicality issues with large electromagnets: most theme-park attendees are likely to be carrying personal electronics that aren't too happy about moving through a magnetic field strong enough to push a rollercoaster car around.Maybe you could use electrostatics to nudge the car back on course. Or, more mundanely, compressed air.Also, there was a recent story about a rollercoaster car that got stuck upside down when the power was interrupted and the emergency brakes locked down. What does the ballistic coaster do when the power goes out?Well, if the car is already in the air and the course is designed properly, it should still land in the receiver funnel. The midcourse nudges should be the difference between a smooth and a bumpy flight, not success or failure. This is where a compressed-air nudge system with a reservoir tank might be better.

But... if the power goes during acceleration? Maybe a compressed-air catapult with a reserve pressure tank there as well. Or possibly the jump could be on the third hill after the initial acceleration, and the brake system could bring a car to a halt before the jump if there isn't enough speed.

Mangetout
06-12-2007, 04:05 PM
It might be possible to have it look ballistic without really being so. If the track were to have a gap that was long enough to be plainly visible by passengers inside the car, but not long enough to let the rear of the car leave the track until the front was already on the other side, the engineering might be considerably more manageable.

The cars would have to be designed to help the illusion. The wheels could extend out from the car, but not far enough to be seen. It might help if they were set up on the body of the car too, so that it would feel more like you were leaving the track when the car went over a gap.
That's not a bad idea - if it was constructed so that the cars were joined by hydraulic rams and the whole train could, when desired, be constrained in a rigid arc shape, the front of the train could be 'pushed' out over the end of a track, across a void and onto the next section. Failure of any component would be disaster though.