Hypothesis about banking turns

Has anyone ever thought about banking the track to the outside of the curve and therefore creating a large amount of negative g's? Is it possible, and if it is, would it be too intense for riders?

Actually you woudl be creating positive G's, just in the oppisite direction.

Sounds pretty dangerous if you ask me.

------------------
Ah what the hell.....Magnum What?

S:ROS blew me away

The only ride I have seen do that is Countdown to Extinction, the vehicles banked to the opposite direction to enhance the feel of intensity.

I highly doubt a coaster will ever do that. Neg. Gs are just too hard on the human body, unlike positive Gs.

------------------
- "I used to be in the audio/visual club, but I was kicked out because of my views on Vietnam........and I was stealing projectors" - Homer Simpson

Maybe if its done in a place where little banking is needed and at a lower speed then maybe it would work. Although i think it would be impossible to put it somwhere when a train is going in excess of 30 or 40 mph.

------------------
G-Forces: The only positive addiction out there!
CoasterCount: 42

The problem isn't that it is hard on the human body. I wish we could get away from that myth, as it simply doesn't apply to the magnitude of forces you're gonna get on a roller coaster.

The problem is that first of all, that's a spot where you're going to tear up the track. Second, that's a spot where you're going to run the risk of flinging the riders off.

Airtime on the top of a hill involves the rider following a ballistic path while the train runs over a curve below that ballistic path. A rider thrown from his seat at the top of the hill will be picked up by the train just over the top. But if you fling a rider out sideways, he'll fly out at a tangent to the curve and land on the midway, in which case you have to chase him down and collect an extra ticket.

--Dave Althoff, Jr.

I could be wrong here, but I don't think the issue is with the track getting torn up. What is coming to mind is inverted coasters. The force on the track is an outward force rather than inward (I don't know if that made sense, but it does to me :)) I think that it would be fine on the track assuming the train was designed to handle it.

I will agree with you on the rider issue. Probably could be done at a low speed, but if half of the "Oh my god my lap bar popped up" stories are true, then you could kiss your behind goodbye on this one.

Patrick trust me its true happened to me on Viper @ SFGAm

------------------
Summer 03-CP, HP, Canobie, SFNE, SFWOA, and SFGAm.

You might be able to say that "negative G's" on the outside of a banked curve occur on the Vekoma flying coaster (i.e., the helix). That is, negative with respect to the train chassis which is located behind the rider. Of course, with respect to the harness, positive G's are created, with the rider occupying a prone position supported by the harness.

Banking on the apex of a small parabolic curve does happen. There are several instances, for example, on B&M standup coasters, which would technically fit the description. These elements, if well timed and of the right magnitude, are especially intense, and make for an interesting ride. I know of no sustained bank outside of a curve in the instance that CoasterMNguy is speaking, however.

I'm not saying these things don't happen Touchdown, I do think however that in most cases, they are over exagerated.

That seems to be fairly common. In most cases the lapbar only goes up one or two clicks. You have to think about it though, you could ride the coaster without a restraint (Viper) and so it really isn't a huge problem.

------------------
www.CaliforniaCoasterNews.com
www.SFMWZone.com

Well, it could be done, but why? Imagine having to wear OTSRs on a woodie... Heavy padded OTSRs.. ugh.
------------------
I don't take offense to idiots. I am an idiot. Hear me roar.

---

Peabody said:
The only ride I have seen do that is Countdown to Extinction, the vehicles banked to the opposite direction to enhance the feel of intensity.

---

For those of you not playing the home game, CTX is now known as Dinosaur. Don't know why I reminded folks of that, but I did anyway. :)

------------------
- John

Rideman, while it's true that a rider physically thrown from the train at the top of a hill would probably land back on the track, unless the train is experiancing true weightlessness, (in which case the rider couldn't be thrown anyway) the rider will not come down in the same position. The curvature of the track is greater than the 0g parabolic path. This is what causes the negative G situation in the first place. The rider will "fly" in a weightless parabolic trajectory. The train, which is experiencing an acceleration AWAY from that 0g path (which is what causes the negative G sensation) will thus be moving AWAY from the rider. If the difference is mild then the train may catch him when it begins its pullout, but even so I really doubt that a passenger who is ejected, flies through the air for a second or two, and then lands on another passenger in the train will be much safer than a passenger that simply hits the tracks.

My hypothesis is based on the fact that it doesn't lead to a lateral-less situation anyway. Well not unless you reverse bank it into an inversion. It actually increases laterals. Do this. Draw a vector straight down and call it "g" draw a second vector of the same magnitude straight to the right and call that "a". These are the forces acting on the rider. (Actually there are the forces that balence these as well, which are the seat force and the side of the car force, but they are equal and opposite.) Add these vectors and you get a total force which points down from horizontal right at about a 45 degree angle. You want your rider to be parallel to this so he experiences no laterals. The obvious solution is to bank the track 45 degrees the "normal" way, which puts the rider parallel with the forces he exerts on the car. He feels no laterals.

You can also put the rider 135 degrees clockwise from vertical and he feels no laterals. He is, however, nearly upside down and experiencing -1.41G for quite an extended period of time.

If you did what I think you are suggesting, and bank the track 45 degrees from vertical clockwise, he would be feeling no force on his butt, but instead feeling ONLY lateral forces. Furthermore, with no lateral frictional "butt" force, all the force will be applied on whatever part of him resists turning, his side on the side of the car or his head on a shoulder harness or whatever. I rather doubt that this is desirable.

One could reverse bank less than ninety degrees and get an acceptable result if the turn is accompanied by a parabolic motion. That would be exactly an "airtime" counterpart of an overbanked turn, and this could also be made relatively gentle. I am suprised that this hasn't been done, especially on hypercoasters that are supposed to be all about airtime. Or maybe it has and I just haven't seen it. This is the only instance where you'd get a better result than just leaving the track unbanked
*** This post was edited by Comatose 4/27/2003 3:24:41 AM ***

Well, Xcelerator's top hat is the extreme case of what you're talking about. It's an 180 degree banked turn banked the wrong way. (compare to Chiller's top hat which is a 180 degree over banked turn banked the "correct way").

------------------
Be polite and ignore the idiots. - rollergator
"It's not a Toomer" - Arnold Schwartzenkoph

Didn't the Cyclone Racer have reverse banking?

------------------
Please visit the small parks. We don't know what's happening behind the scenes
Woodencoaster.com

While it is true that in airtime the rider doesn't follow the exact same path as the train, the forces required to bring him back in line are pretty small. This wouldn't be the case for a reverse banked turn unless it is a very low G turn.

Basically, a reverse bank turn would have to be taken very slowly to keep negative G's and lateral G's to reasonable numbers.. The end result would be a boring turn. Probably not too comfortable as you just slid to the outside of the car and just rested there.

The track wouldn't be at all hard to design in steel, and probably not a problem in wood either. The limited G's that the rider can take in that position would keep the mechanical forces pretty low.

Jim, that's absolutely true, but what, exactly, is going to apply those forces if the rider is physically ejected from the train? Flapping his arms?

I'm 99% sure it's because it increases laterals instead of decreasing them, and if you want laterals just make the layout more compact and keep the turn flat.

(The 99% sure comes from me being 100% sure it increases laterals and 99% sure that is considered "bad", or at least this is a bad way to do it)

Banking a turn the opposite way doesn't increase laterals at all.

If the bank is correctly calculated and implemented (or for that matter, incorrectly but the same way as the regular banking), the laterals will not be any different and will not have any different change with respect to change in speed as a regularly banked turn.

If you want the physics I'm sure plenty of people (including myself) could write up a little summary.

------------------
Be polite and ignore the idiots. - rollergator
"It's not a Toomer" - Arnold Schwartzenkoph

Actually a reverse banked turn doesn't increase laterals. What it does is create a horrible combination of laterals and negative G's.

I think the more relevant aspect of the whole *banking* issue is RELATIVE banking....not so much in relation to the ground, but in relation to the adjacent trackwork. Legend's helix provides an excellent illustration of how some *relatively flat* track in the midst of some heavily banked track can provide an out-of-control mine-ride FEEL....without having to resort to questionable engineering practices...;)
------------------
"Brian, there's a message in my AlphaBits, it says 'ooooooo'"
"Peter, those are Cheerios"....Family Guy is BACK!!!