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Name: Mike
Status: educator
Grade: 9-12
Location: NJ
Country: N/A
Date: 12/26/2005

What is the max G forces that a person can withstand on a roller coaster?

Sustained acceleration is about 4 g's before losing consciousness. Assuming normal health, this will not cause death. Momentary accelerations can be upwards of 15 g's without any severe problems. Most roller coasters do not go beyond 3.8 g's. A few have moments of 4 or 5 g's. Some of these with higher momentary accelerations are bumpy wooden roller coasters. It is best to check the specifications of a specific ride with the local park you plan to attend. In general, amusement parks want their guests fully safe, awake, aware, healthy, and alive. Although stationary amusement parks have excellent per passenger mile records (it is far more dangerous driving to and from the park), the bad press they suffer from a small injury or even an inconvenience can mean the difference between a profitable season and a loss. Please note that the safety record of temporary carnivals are not as good.

The most injury prone ride at a park is the carrousel. Most of the injured people miss the step up or try getting off the horses while in motion. Once seated, do not get off until the ride finishes. The non-seated rider can be hit in the head by the oscillating horse or become disoriented while trying to move on a spinning ride.

The next most common injury in amusement parks is blisters because of wrong footwear. Sunburn and dehydration rank high, also. Headaches and stomach upset not associated with sun exposure or dehydration are much less common than thought of by the public. Collisions with waste containers, or other items are common injuries because many people are looking at the rides and not where they are going.

Engineers try to make amusement parks as safe as possible. Some safety responsibility must be taken on by the park guests. Engineers cannot design for every possible poor judgement a guest may exercise. Some of these guest responsibilities include not eating (including chewing gum) on rides, using all of the designed and recommended safety equipment, following height limitations (this has to do with the passive safety design of the ride, not discrimination), not riding while intoxicated, not going on rides where a medical condition may be exacerbated, staying hydrated, reading all instruction signage, and following all verbal instructions.

The major parks have strict certification requirements for their employees to operate rides. This training includes proper ride operation, how to identify any anomalies, and includes emergency procedures ranging from weather issues, power failure, ride failure, guest problems, and other things that might arise from time to time. There was a blackout in the summer 2003 in the northeast of the United States. Rides were abruptly without electricity. Even under this extreme condition, no injuries occurred. Some of the braking blocks may have had greater than 4 g's, but it was brief. The trained operators were able to appropriately reach guests on rides, and safely get them back to the ground. In some cases, roller coaster rescues took over an hour. Inconvenience, yes, but no injuries. This safety record is due to the proper training of park staff.

Although your question was only asked about accelerations, that question is usually followed by safety questions. We hope that you have a safe and fun experience at the amusement park.

By the way, we hope you mean acceleration with a lower case g and not the Universal gravitational constant.

---Nathan A. Unterman

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