During a roller coaster ride, guests experience a unique combination of sensations.
Whether it’s being pushed back into your seat, or flung out of it; roller coasters
have been specifically designed to provide riders with a select combination of feelings.
These feelings differ heavily at certain points of the ride, creating an overall experience
that’s unlike any other.
In short, roller coasters are all about forces.
The trains undergo a huge number of directional changes as they navigate the track, each of
which provide a particular force, and sensation, on riders.
In this video, we’ll get to understand the types of forces experienced on roller coasters,
as well as the sensations each type causes guests to feel during their thrilling ride.
At this point, some of you may be asking the question: “What are forces?”.
A force can be described as a push or pull on an object, as a result of an interaction
with another object.
In the case of roller coasters, the design of the track produces a force on the trains,
causing them to follow a specific path.
You’ll often see the term g-force used to describe roller coasters.
G-force, short for gravitational force, is a measurement of acceleration, and is not
specifically a force.
However, a force on an object causes that object to accelerate.
In the case of gravity, the force pulling everything towards the centre of the earth
causes objects to accelerate downwards when dropped.
This acceleration is denoted 1g, 1 g-force, and causes the perception of weight as we
know it.
Therefore, a roller coaster which boasts a maximum of 5gs, 5 g-force, causes riders to
feel 5 times their normal weight, as they are effectively experiencing an acceleration
5 times larger than the one pulling them to the centre of the earth.
During most roller coaster rides, guests will experience a range of g-force types, each
of which act in different directions.
Linear g-forces occur in the forwards, and backwards direction; positive and negative
g-forces occur in the upwards, and downwards directions respectively; while lateral g-forces
occur from side to side, in the left and right directions.
Linear G-forces occur as a result of an increase, or decrease in speed.
A great example of this is a launch.
As the train of the ride accelerates, guests are subject to linear g-forces, which occur
in the direction of speed change.
However, as the trains themselves are being accelerated, and not the riders, guests become
pinned into their seats.
This allows for the riders, and trains, to accelerate together along the launch straight.
A sudden reduction in speed, caused by a brake run for example, causes riders to travel forwards
in their seat, until stopped by the restraint.
Positive and negative g-forces occur in opposite directions.
Positive g-forces act in the upwards direction, while negative g-forces act in the downward
direction.
Both of these g-force types can be experienced through a change in elevation.
Riders will experience positive g-forces in valleys, sections of track which continuously
angle towards the upwards direction.
At the bottom of drops, riders are often pushed down into their seat, causing them to feel
heavier than normal.
This type of force is usually the most common on roller coasters.
A ride which boasts a maximum g-force of 5, allows guests to experience 5gs of positive
force at some point during the ride.
Negative g-forces, on the other hand, provide the opposite sensation.
As riders crest the hill of a roller coaster at speed, they are being subject to negative
g-forces, which pull the trains down, keeping them secured to the track.
During these sections, riders often rise up and out of their seat, causing them to be
pushed down by their restraint.
This phenomenon is known effectively as airtime.
Roller coasters use a mixture of strong, and weak, negative g-forces to subject guests
to a range of sensations.
Weak negative g-forces, known as floater airtime, give riders the sensation of total weightlessness,
causing them to ‘float’ in the air.
Strong negative g-forces, known as ejector airtime, cause guests to quickly rise out
of their seat, pinning them to the underside of their restraint.
Ejector airtime is much more aggressive than floater, often occuring at the top of sharp
hills.
Finally, the last g-force type is lateral.
Lateral g-forces occur from side to side, in the left and right directions.
It can often be experienced during sharp turns in the track, especially ones that are unbanked.
For example, wild mouse coasters, ones with flat, sudden turns, produce high lateral Gs.
As this occurs, riders are thrown to the side of the car, in the opposite direction to the
movement of the train.
Extreme lateral g-forces however, are quite uncomfortable on roller coasters.
To reduce them, roller coaster designers bank the track, which converts lateral g-forces
into positive g-forces.
This allows for the ride to be more comfortable for all guests on board.
To recap, we have 4 main g-force groups.
Linear G-forces, which act in the forward and backward directions; Positive and Negative
G-forces, which act in the upwards and downwards directions respectively; and lateral g-forces,
which act in the left and right directions.
Each group causes riders to move in the opposite direction to which the g-force acts; as you
rise up in your seat, as you experience downward pointing negative g-forces.
Interestingly, on a roller coaster ride, it isn’t only the intensity of the accelerational
forces that affect the sensations felt by riders.
Sustained G-forces, ones which last for several seconds, affect guests more than extreme spikes
of intensity.
For example, a long sweeping bend could subject riders to 3gs of positive force for several
seconds.
During this time, the body finds it difficult to pump blood up to the head.
The continued exposure puts stress on the body, which can lead to riders to begin to
greyout.
During this phenomenon, guests field of view beings to shrink and become excessively grey.
If riders are subject to a greyout for extended periods of time, they may blackout and become
unconscious.
Fortunately, once the forces have been removed, riders regain consciousness and normal vision,
with no damage done to the body.
To conclude, forces play a large part of any roller coaster ride.
Designers ensure that the g-forces experienced throughout the circuit are exciting, yet comfortable
to the riders onboard.
So next time you’re on a roller coaster, take notice of the forces experienced, and
how they move you in your seat.
Thank you for watching, and I’ll see you all next time.
Check out our brand new podcast - Coaster Bot Rambles
where I talk about Theme Parks with roller coaster novice Zoe.
You can find us on iTunes, and all good podcast apps, as well as on Twitter, @CBRPodcast