Roller Coasters and Accelerations
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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Update: June 2012