B&M flying coaster G force

[kadabrium]

Hi guys I would like to ask this question

how much is normally the G force at the bottom of a B&M flyer's first drop?

im coming up with this question because I could not really understand why positive G forces are possible to be much greater than negatives.

Like you get +5G not quite rarely at all but I could not recall anything with greater than -2g.

[robbalvey]

If you went -5Gs, your legs would probably be torn off off as you were thrown out of the train! That is, if the train itself isn't ripped off the tracks!

 

-5Gs means that 5 times the weight of whatever it is being forced against gravity. So in the case of a rider, let's say he's 200 pounds, that's ONE THOUSAND POUNDS of force trying to push the rider out of the train into space!

 

Whereas a positive G, pushes you back into your seat. 5 positive Gs isn't that safe either for long sustained periods of time, but it sure is a lot safer than -5Gs!

 

---Robb "Hope I'm explaining this correctly as I'm not an engineer by any means..." Alvey

Edited December 30, 2012 by robbalvey

[kadabrium]

understood, but as I pulled the example,

a typical b&m flyer does not seem to have within 1.5Gs(the green range in NoLimits apparently) at the bottom of its first drop, does it?

[ManiaMuse]

I would imagine it is because positive Gs force you into the seat where the forces are spread over a larger area (back/bum/back of legs/back of head) hence the forces are more tolerable. Plus your bum has a bit of give to be squished anyway.

 

Generally restraints only pin you in a relatively small area (top of legs/waist) so negative forces are concentrated more intensely while the rest of your body has much more freedom of movement. OTSRs don't usually pin your shoulders so being thrown into them would be painful. Plus your spine/neck can travel much further which guess would could cause whiplash problems if negative Gs are too high.

[kadabrium]

I would imagine it is because positive Gs force you into the seat where the forces are spread over a larger area (back/bum/back of legs/back of head) hence the forces are more tolerable. Plus your bum has a bit of give to be squished anyway.

 

Generally restraints only pin you in a relatively small area (top of legs/waist) so negative forces are concentrated more intensely while the rest of your body has much more freedom of movement. OTSRs don't usually pin your shoulders so being thrown into them would be painful. Plus your spine/neck can travel much further which guess would could cause whiplash problems if negative Gs are too high.

So why these problems are not around at, to say, manta or star ripper's first drop?

[DougMJr]

The restraints on a flyer use a vest, which increases the surface area of restraint on body, which will allow the body to be forced into it with slightly greater force than a regular OTSR.

 

But flyers cannot be too forceful as there is still no support for the neck. Flyers have low g-forces because of the position you are in, the ride still needs to be comfortable.

[Double0Kevin]

From what I remember from high school physics, the human body can't go beyond -2Gs. I believe that is the threshold where you would die. Anyone able to confirm this, or am I making it up?

[Wes]

http://en.wikipedia.org/wiki/G-force#Vertical_axis_g-force

[A.J.]

Flying coasters are a bit weird. They're weird because the forces that riders feel at the bottoms of hills are equivalent to forces experienced during a launch (acceleration) and a brake section (deceleration), because your body is in a face-down (or face-up) position.

 

When you are traveling through the bottom of a drop while face down or an airtime hill while face up, the vertical forces push your body against the vest and ankle restraints. Even though the forces are technically in the vertical direction, your body experiences a sensation similar to the one felt when you hit a roller coaster's brake run, but much more intense.

 

Subsequently, when you're going over the crest of a hill while face down or the bottom of a drop while face up, the vertical forces push your body against the back of the seat. That sensation is like the one experienced on a launched coaster, but again much more intense.

 

I'm pretty sure that you typically won't see any more than 3 Gs at the bottom of a flyer's drop if you're in the face-down position, and no more than 5 Gs if you're in the face-up position (the bottoms of pretzel loops are really intense).

 

EDIT: Quick and dirty infographic -

I think I wrote everything correctly here.

[Wes]

Alternately

[Tanks4me05]

http://nolimits-exchange.com/news/g-force-lesson/35

[Yamez]

Alternately

 

 

You're my hero.

[Loefet]

A little dodgy g-log of a S:UF from a few years ago, our accelerometers have gotten a lot better since then:

 

Blue = Vertical forces, Red = Linear forces, Green = Lateral forces

(Note that these are when sitting down at first, then the tilt will change the directions on the Blue and Red lines, as A.J. described on the previous page)

[A.J.]

Here's that diagram again to go with Loefet's graph -

 

 

Obviously the spike in the graph is during the Pretzel loop.

 

Going off of what Loefet said about the directions - remember that the forces exerted on the train aren't necessarily the same as the forces experienced by the rider, especially relative to the passenger's line of sight.

 

It's like being in a centrifuge - if you're sitting upright and facing the center, it's going to feel like you're being pressed backward against the seat. But, if you're sitting on your back with your feet pointing away from the center, it's going to feel like you're being pressed downward into the seat.

[bottom_feeder_13]

On a similar note, since I don't want to start a new topic for it, does anyone have g graphs for Cyclops in the back seat?

[Anything]

I have heard so much about the pretzel loop!