Heart-line, Solarplexus-line - what line is it really?

Saturday, November 12, 2005 3:22 PM
One of the biggest steps in coaster design in the last decades was the centering of lateral rotations of the rider during the ride of the coaster around the so called heartline-axis.
I noticed that in some 0G rolls though, the rolling axis seems to be above the heart somewhere near the head of the riders or even higher (in a corkscrew inversion, the axis is far above the rider's head anyway).

Does anyone know what the first coaster designed along these principles was (or have more information how the whole idea came about)?

I wonder if there is any info how they ended up with the heartline, and not the belly-button line (which would maybe be more according to Leonardo daVinci).
Shouldn't the heart-line be indeed called the solarplexus-line, since the perceived "center" in that area of the body is definitely the Solarplexus (which also coincides with the breast -chakra of certain eastern medicines)?

Why does the axis of rotation seem more toward "headline" in some rolls?

Saturday, November 12, 2005 3:59 PM
I think Ik now what you mean...I kinda felt it on Volcano : The Blast Coaster @ PKD. When I rode it, it didn't feel like a heartline roll..it just felt like a very disorienting flip to the side..LOL. I know it sounds kinda weird..but that's what it felt.

I LOVE heartline rolls! They are AWEOMSE!

Saturday, November 12, 2005 4:40 PM
The entire coaster is centered around the riders heartline, not head. The reason a Zero-G roll looks as if its at the head is the positioning of the roll in relation to your perspective, let alone that, unlike a heartline roll, the roll is happening at the top and crest of a hill.

Corkscrews dont base rotation itself on the rider's heartline, but rather takes the pre-existing element and format it to a more flowing, and more heartlined track, to lessen strain on rider.

All track (on modern steel coasters, Arrow and prior steel coasters are a different subject completely) is heartlined for safety.

Saturday, November 12, 2005 5:10 PM
So do you think that all the manufacturers and designers make the heartline rolls differently? Do you think they all feel the same? ...and I don't mean roughness or smoothness, I mean when you actually experience it...I was just wondering...not that's it's that serious.
Saturday, November 12, 2005 5:20 PM
The rider's heartline is a heartline, there is no way to change it.

But, the measurment of offset that is needed for heartline changes depending on vehicle design and such, so in essence, yes, each manufacturer does make it differently depending on distance from heartline to the track (seperation offset).

Sunday, November 13, 2005 12:54 AM
A short person's head might be where a tall person's heart would be anyway. It's all splitting hairs :)
Sunday, November 13, 2005 3:56 AM
Of course, and there's also the fact that with 4-abreast there is no way how the train could spin around everyones heart.

But each time I look at pics like this...


...it seems the train spins roughly around the heartline for some section of the roll, but before and after the rolling axis does seems to be closer to the rail (the rail not giving enough way to the train for it to fit into the roll up to the rider's chest)

Maybe this is some engineering secret of B&M.

Sunday, November 13, 2005 2:30 PM
even in 2-abreast there's no way the train could spin around everyone's heart.
Monday, November 14, 2005 1:08 AM
No, but the height of the heart is a much better starting point and will result in much friendlier forces in the seats at 2 and 4 abreast.

As for B&M zero-g rolls appearing to rotate around an axis that isn't quite the heartline... that's more of an engineering "secret" of Werner Stengel & his crew and the target vertical g's actually being very very slightly different from true parabolic zero g.

Annnd as for heartlining in general, the basic idea is that rides should be designed around the motion path of their riders (see: B&M, Intamin, similar etc.) instead of rotating things around a point between the rails or even the track spine (see: Arrow, Morgan, most old and some new Vekoma, similar etc.). This idea and others regarding track design and shaping were pioneered by the partnership of Werner Stengel and Anton Schwarzkopf. By conducting all (or in special cases, most) of the rotation of a ride around an imaginary line drawn at roughly the elevation of the average rider's heart, unwanted lateral Gs can be much more easily controlled and thus reduced to near negligibility (= no/minimal headbanging).

In most seating configurations (save inline seating), it is, naturally, impossible to design around every rider's 'heartline'. However, the differing forces depending on seat are still much, much more easily coached into acceptability on heartlined rides than on unheartlined rides. Even so, as seats get farther on either side of the design heartline, the differing gs become greater, restricting the design possibilities of a given ride in some cases. The most noticeable result of this is in the rate of roll that can be comfortably carried out. Look at certain banking changes on the 2-abreast Intamin rockets Kanonen and Storm Runner. There are moments of extremely fast rotation... noticeably faster than on any 4-abreast ride. Now look at the difference between the maximum rate of roll on a 4-abreast B&M floorless and an 8-abreast dive machine. The 8-across seating of the dive machine means that the variation from 'wingtip' to 'wingtip' of the train will be significant (perhaps why one side of the train is "better" than the other on Sheikra's immelman) in terms of forces experienced.

Hopefully that was a thorough enough explanation of things... but if it wasn't feel free to fire off some more questions.

- BB

Monday, November 14, 2005 1:13 AM
Wow. You actually made me understand it. Good Job!
Monday, November 14, 2005 12:04 PM

BBSpeed26 said:
As for B&M zero-g rolls appearing to rotate around an axis that isn't quite the heartline... that's more of an engineering "secret" of Werner Stengel & his crew and the target vertical g's actually being very very slightly different from true parabolic zero g.

...so maybe the axis of rotation is a little higher than heartline in the roll to produce some positive Gs so people stay embedded in their seats throughout the roll (instead of receiving all the lateral acceleration through the OTSR or just the side of the seat, in case their were truly floating 0G wise).
Probably this creates a more pleasurable experience.

Monday, November 14, 2005 2:22 PM

From that thread:

Badnitrus said:
I have worked with coaster blueprints and I know that the track does not rotate around the "heart" of the riders, or anywhere close. For instance, on Intamin Impulse coasters, the "heartline" is actually the center of mass of the train, which is located a little above the headrests. B&M coasters are the same way, the heartline is closer to the wheels of the train... I'm not sure exactly how one can be weightless in a B&M heartline with the cars rotating about an axis much lower come to think of it, I never really sat down and questioned it too much.... but I do know that some of them throw you to the side more....

Now Togo heartlines... those definitely feel like the heartline is literally through your heart, and those heartlines have a completely different feel to them, more like a carpet being pulled out from underneath you...

-Keith "Badnitrus" McVeen

*** Edited 11/14/2005 7:35:27 PM UTC by ApolloAndy***
Monday, November 14, 2005 3:48 PM
I won't comment on Impulses (having recreated them once I decided that they are a bastard child of roller coaster designing).

That being said, the reason Keith's probably perceiving the center ("heartline") path as actually being well below the riders heartline on B&Ms has more to do with the other Gs and the leadins that are taken into account when banking rides. For instance, the only time rotation is obviously around the heartline, to the untrained eye anyway, is in heartline rolls (Hydra, Collossus for example). When you have to compensate for vertical gs, it may appear as though the heartline actually lowers to become closer to the chassis of the train. In a left hand, 180 degree turn, for example, the turn itself is not a complete circle. As the heartline path begins to move left, the ride will bank left, but the actual track will begin to move to the right, as with a heartline roll. Over time, however, the slight rightward displacement of the track will appear to be reduced due to the actual leftward motion of the heartline path. The perceived "lowering" of the heartline does not actually occur. The "lowering" also appears becomes to become even greater when the ride executes a maneuver in which there are positive vertical gs of any kind.

I have to run at the moment, but later I will post some visual examples of this to back up and clarify what I'm saying.

- BB

[edit] Look here. This is an overhead schematic of Eurostar taken from Stengel GmbH. One of the red lines is the heartline path, and when you look closely at it, it should appear to be the line with the most consistant and smooth changes in radius throughout the course of the track. This is a similar schematic for Gerstlauer's Typhoon coaster.

To see some of the things I've been talking about, take note of the heartline path of Eurostar's "Zero"-g roll. The heartline has a slight wiggle in it, which, coupled with a similar and ever-so-slight wiggle in the otherwise parabolic arc of the heartline through the roll, produces the not-quite-zero-g nature of the roll that I alluded to previously. If you look very closely, you can see the slight change in path in this picture. Also note the completely straight path of the heartline through Typhoon's heartline rolls. The goal in heartline rolls is simply to rotate you about as near to your natural axis as possible, allowing you to experience whatever forces may accompany such a roll, so the g-compensating wiggle of the zero-g roll is not required.

As for disputing Badnitrus's post in that previous topic (BTW... I think his more telling post was when he said "I don't really know all the technical details..."), take a look at the Typhoon schematic again, and compare it to this 3d view of it. Find the track between the third block brake and the following upwards helix, and look at it very closely, focusing especially on when the track transitions from turning to straight, and then from straight into the upwards helix. If you look very closely at the track, you'll see the visual effect I was talking about before that likely confused our friend Keith. When the heartline path moves left entering the turn, the track does not have to move as far right in banking around the heartline as it would in a heartline roll or a zero g roll because the heartline path is smoothly leading into a helix to the left. Here is an angle from right within the helix that may or may not help you see what I mean. Do Not pay attention to the flat turns in and out of the main block brakes, as these disregard heartlined banking in favor of intentional, mouse like lateral g turns.

Basically the bottom line is that modern roller coasters ARE designed around an imaginary line above the track, which is referred to as the "heartline" due to its proximity to the average rider's heart. Certain implementations of this may appear different and may give the impression of a different axis being used, but in general, this is not the case, and is simply a result of properly designing a ride with respect to the heartline.

Hopefully that clears some things up.

*** Edited 11/15/2005 5:34:23 AM UTC by BBSpeed26***

Wednesday, November 16, 2005 9:04 AM
coastersandmore blocked the illustrations


but your explanation is so interesting, they should feature it on their site -

thanks a lot for the research you obviously put into this.


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