Lateral G's on a Wooden Coaster

Basically, I'm trying to create the most intense(but safe) wooden coaster I can. At the moment the ride gets up to 2.1 G's laterally and I was wondering if that's okay. It also gets to -1.8 G's in the back at one point. Bear in mind, I'm trying to push the limits so if those are the maximum that would be safe, that's perfect!

Depending how quickly you accelerate to that, that should be ok. It would certainly be intense but if you dont go from 0 to 2.1 instantly I dont see an issue.

I'll discuss this from a real world standpoint. It's an intersting subject.

Professional coaster designers use the CEN (Europe) or ASTM (US) standards for tolerable acceleration on the human body. I've been trying to get my hands on those standards, but I'm not sure my local university libray has a copy on file. The only other way to get a set would be to buy one, but that would cost me over $100, and I don't want them that bad.

As a substitute, I've been using the New Jersey Carnival Amusement Ride Safety Regulations, which you can find here: http://www.state.nj.us/dca/codes/ridesafetyunit/pdf/ridesafetyregs.pdf. So far as I know, New Jersey is the only state that has any sort of regulations on what g-forces are allowable on rides. You'll see that they are very generous, probably in excess of what most ride manufacturers and insurance companies would allow.

If you go to the link I posted, the g section starts on page 50. If you look at page 53, you'll see that the lateral g limits are based on how long the forces last (which is consistent with years of medical research on astronauts, fighter pilots, and the like). Any force that lasts less than 0.2 seconds is essentially a "collision" (or bump, or whatever you want to call it, and not covered by these rules). From 0.2 to 1.0 seconds, 3 lateral gs are allowed, beyond 2.0 seconds only 2 lateral gs are allowed, and between 1.0 and 2.0 seconds, you just follow the line to figure out how much is too much. So, a short little 10-degree or so "adjustement" can be quite sharp, but a 540-degree flat helix has to be limited to 2 gs.

Back on page 51, it says that you can't exceed 90 seconds, after that you have to give the riders a break. Also on page 53, it says the above limits assume that there is a divider in the seat that keeps the inside passenger from crushing the outside passenger. If there isn't a divider, you either have to always put the bigger passenger on the outside (not too hard with flat rides, but goodbye to having both left and right turns on a roller coaster!), or limit lateral gs to 0.7 gs. I suppose you could always load the big guy on the right, have 2.0 g left turns, and limit all your right turns to 0.7 gs. Easier to just use a divider, I think.

Page 55 also says that if you transition from left lateral gs to right lateral gs (or vice versa), the transition has to take at least 0.2 seconds, so you can't just instantly go from a 2.0 g turn in one direction to a 2.0 g turn in the opposite direction. But 0.2 seconds is fairly short, and easy to work into your design.

I hope this helps. Feel free to hit me with more questions. I don't work in the amusement industry, but I am a degreed engineer, and can help interpret technical documents like these regs.

^Very nice post. That has to be the best explanation of allowable G's I've ever seen!