This Interactive allows the user to explore the design of a roller coaster. You will learn about the variety of decisions that have to be made by a coaster designer in order to create the desired rider experience. Factors that affect the thrill factor of a ride while insuring rider safety are discussed.
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Roller Coaster Design
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It is the goal of every coaster designer to design a roller coaster that is both thrilling and safe. The design process involves several decisions that must be made about the height and curvature of the various sections of the track. An understanding of the physics of circular motion is used in order to make informed decisions that result in the intended rider experience.  In this widget, you will learn about the decision-making process. Information regarding the following five locations on the track is provided:     A. the height of the initial hill from which the cars are released,     B. the height and radius of curvature of the top of a loop,     C. the radius of curvature of the bottom of the same loop,     D. the height and the radius of curvature of the top of a hill, and     E. the radius of curvature of the bottom of the same hill. Guidance will be provided as you step through the entire design process. Attention should be given to how the decisions that are made affect the rider experience.
Select a height from the choices below. You will always have the option to return to this screen and change it later.
Selecting the Height of the Initial Drop
Height of the initial drop (m)
The first decision that must be made is a decision regarding the height of the initial drop. The coaster cars will be released from rest (nearly) from the top of a tall hill. The potential energy possessed by the riders is transformed into kinetic energy as the riders descend to lower locations. The higher that this location is, the more potential energy that the car will possess … and the faster that the car will move at every other location on the track.
50 m
60 m
70 m
80 m
Pick a Section to Design
First Drop Height = 80.0 m
Design the Hill
Design the Loop
Change First Drop Height
The various design elements of a roller coaster can be designed separate from one another. The rider's experience within a loop is not dependent upon the design of the adjacent hill … and vice versa. While the rider experience on both the loop and the hill depends on the height of the initial drop, they do not depend upon the design features of each other.  Tap on either the loop or the hill to begin the design for that section.
B
Design the Hill
Loops create thrill by gradually changing the magnitude and direction of the acceleration. There is a large acceleration at the bottom of the loop (C) - sometimes as much as 3•g to 4•g - and a much smaller acceleration at the top of the loop (B) - very close to 2•g. Additionally, riders experience a varying normal force … leading to sensations of heaviness at the bottom and (in some designs) sensations of partial weightlessness at the top of the loop. To begin the loop design, tap on either the top or the bottom of the loop.
First Drop Height = 80.0 m || Loop Design
Loop Bottom Design Goals:  • faster   • a > 20 m/s2   • sensations of heaviness   • Fnorm: > 3 Gs and < 5 Gs  • upward a and Fnet
Design the Loop
C
Loop Top Design Goals:  • slower   • a > 10 m/s2   • weightless sensations   • Fnorm: > 0 Gs and < 2 Gs   • downward a and Fnet
D
First Drop Height = 80.0 m || Hill Design
Hill Bottom Design Goals:  • faster   • acceleration: > 20 m/s2   • sensations of heaviness   • Fnorm: 3 Gs to 4 Gs   • upward a and Fnet
Hill Top Design Goals:  • slower   • acceleration: 5 - 15 m/s2   • weightless sensations   • Fnorm: 0.5 Gs to 0 Gs             (occasionally negative Gs)   • downward a and Fnet
Hills create thrill by lifting riders partially or entirely off their seats near the crest of the hill (D). This reduces normal forces to 0 N, creating a weightless sensation. In extreme cases, the acceleration is so great, that the safety bar pushes down on the riders, creating a condition known as negative Gs. At the hill bottom (E), riders experience large normal forces to slow their bodies down and to provide the centripetal acceleration required to negotiate the curve of the track. Riders may experience as much as 3 to 4 Gs of normal force. Finally, from the crest (D) to the bottom of the hill (E), the track has a parabolic shape allowing riders to experience a free fall sensation. To begin the hill design, tap on either the top or the bottom of the hill.
E
Loop Top: Design and Safety Considerations
Design the Loop Bottom
First Drop Height = 80.0 m || Loop Design || Top (B)
There are two design parameters that are important for loop tops - the height and the radius of curvature of the loop top. Control of these parameters allows the coaster designer to create the intended rider experience.  There are two safety concerns associated with loop tops: (1) If riders are moving too slowly, the acceleration decreases to a value of 9.8 m/s2. This is the free fall acceleration. You don't want riders in free-fall.  (2) The accelerations of riders should not be greater than ~40 m/s2. Accelerations that are this high result in the rushing of too much blood out of the brain and a subsequent risk of riders blacking out. There is a final design consideration that pertains to loops in general. Clothoid-shape loops have a radius at the top that is about 1/3-rd the loop's height and a radius at the bottom that is about 2/3-rd the loop's height.  Click the View Design Data button to view data for a variety of designs.
View Design Data
First Drop Height = 80.0 m || Loop Design || Bottom (C)
Loop Bottom: Design and Safety Considerations
Design the Loop Top
The one design parameter that is important for loop bottoms is the radius of curvature of the loop bottom. Control of this parameter allows the coaster designer to create the intended rider experience.  There is one safety concern associated with loop bottoms: The acceleration of riders should not be greater than ~40 m/s2. Extreme accelerations result in the rushing of too much blood out of the brain and a subsequent risk of blackout. While not all riders blackout at this acceleration, there would be enough that would to distract others from riding your coaster. Accelerations greater than 60 m/s2 would require a special G-suit. There is a final design consideration that pertains to loops in general. Clothoid-shape loops have a radius at the top that is about 1/3-rd the loop's height and a radius at the bottom that is about 2/3-rd the loop's height.  Click the View Design Data button to view data for a variety of designs.
Hill Top: Design and Safety Considerations
Design the Hill Bottom
There are two design parameters that are important for hill tops - the height and the radius of curvature of the hill top. Control of these parameters allows the coaster designer to create the intended rider experience.  There is one safety concern associated with hill tops: The accelerations are downward at the top of the loop. Gravity can provide an acceleration up to 9.8 m/s2. For accelerations greater than 9.8 m/s2, a safety bar must provide the remaining acceleration. As accelerations approach 19.6 m/s2,  a dangerous condition can result. As the upward-moving riders reach the crest of the hill, the force of the safety bar pushes the riders' flesh and bones downward. Yet there is nothing to prevent the upward flow of blood through the blood vessels towards the brain. The rapid rushing of too much blood to the brain can cause some riders to redout. Without a special G-suit, riders are at risk of experiencing the fatal condition of breaking blood vessels in the brain.  Click the View Design Data button to view data for a variety of designs.
First Drop Height = 80.0 m || Hill Design || Top (D)
Hill Bottom: Design and Safety Considerations
There is one design parameter that is important for a hill bottom - the radius of curvature of the hill bottom. Control of this parameter allows the coaster designer to create the intended rider experience.  There is one safety concern associated with hill bottom: The accelerations of riders should not be greater than ~40 m/s2. Accelerations that are this high result in the rushing of too much blood out of the brain and a subsequent risk of riders blacking out. While not all riders black out at this acceleration, there would be enough that would to distract others from riding your coaster. At accelerations greater than 60 m/s2, it would require a special G-suit to safely ride the ride. Click the View Design Data button to view data for a variety of designs.
First Drop Height = 80.0 m || Hill Design || Bottom (E)
Design the Hill Top
Loop Top: Design Data and Rider Experience Reports
Tap below for aQuick Linkto Location B Data for a first drop  height of ...
* Riders were in a state of free fall at the top of the loop.
Tap below for aQuick Linkto Location C Data for a first drop  height of ...
Loop Bottom: Design Data and Rider Experience Reports
Hill Top: Design Data and Rider Experience Reports
Tap below for aQuick Linkto Location D Data for a first drop  height of ...
Hill Bottom: Design Data and Rider Experience Reports
Tap below for aQuick Linkto Location E Data for a first drop  height of ...
First Drop Height = 70.0 m
First Drop Height = 70.0 m || Loop Design
First Drop Height = 70.0 m || Hill Design
First Drop Height = 70.0 m || Loop Design || Top (B)
First Drop Height = 70.0 m || Loop Design || Bottom (C)
First Drop Height = 70.0 m || Hill Design || Top (D)
There are two design parameters that are important for hill tops - the height and the radius of curvature of the hill top. Control of these parameters allows the coaster designer to create the intended rider experience.  There is one safety concern associated with hill tops: The accelerations are downward at the top of the loop. Gravity can provide an acceleration up to 9.8 m/s2. For accelerations greater than 9.8 m/s2, a safety bar must provide the remaining acceleration. As accelerations approach 19.6 m/s2,  a dangerous condition can result. As the upward-moving riders reach the crest of the hill, the force of the safety bar pushes the riders' flesh and bones downward. Yet there is nothing to prevent the upward flow of blood through the blood vessels towards the brain. The rapid rushing of too much blood to the brain can cause some riders to redout. Without a special G-suit, riders are at risk of experiencing the fatal condition of breaking blood vessels in the brain.  Click the View Design Data button to view data for a variety of designs.
First Drop Height = 70.0 m || Hill Design || Bottom (E)
First Drop Height = 70.0 m || Loop Design || Top (B)
First Drop Height = 70.0 m || Loop Design || Bottom (C)
First Drop Height = 70.0 m || Hill Design || Top (D)
First Drop Height = 70.0 m || Hill Design || Bottom (E)
First Drop Height = 60.0 m
First Drop Height = 60.0 m || Loop Design
First Drop Height = 60.0 m || Hill Design
First Drop Height = 60.0 m || Loop Design || Top (B)
First Drop Height = 60.0 m || Loop Design || Bottom (C)
First Drop Height = 60.0 m || Hill Design || Top (D)
There is one design parameter that is important for a hill bottom - the radius of curvature of the hill bottom. Control of this parameter allows the coaster designer to create the intended rider experience.  There is one safety concern associated with hill bottom: The accelerations of riders should not be greater than ~40 m/s2. Accelerations that are this high result in the rushing of too much blood out of the brain and a subsequent risk of riders blacking out. While not all riders black out at this acceleration, there would be enough that would to distract others from riding your coaster. At accelerations greater than 60 m/s2, it would require a special G-suit to safely ride the ride. Click the View Design Data button to view data for a variety of designs.
First Drop Height = 60.0 m || Hill Design || Bottom (E)
First Drop Height = 60.0 m || Loop Design || Top (B)
First Drop Height = 60.0 m || Loop Design || Bottom (C)
First Drop Height = 60.0 m || Hill Design || Top (D)
First Drop Height = 60.0 m || Hill Design || Bottom (E)
First Drop Height = 50.0 m
First Drop Height = 50.0 m || Loop Design
First Drop Height = 50.0 m || Hill Design
Hill Bottom Design Goals:  • faster   • acceleration: ~20 m/s/s   • sensations of heaviness   • Fnorm: 3 Gs to 4 Gs   • upward a and Fnet
Hills create thrill by lifting riders partially or entirely off their seats near the crest of the hill (D). This reduces normal forces to 0 N, creating a weightless sensation. In extreme cases, the acceleration is so great, that the safety bar pushes down on the riders, creating a condition known as negative Gs. At the hill bottom (E), riders experience large normal forces to slow their bodies down and to provide the centripetal acceleration required to negotiate the curve of the track. Riders may experience as much as 3 to 4 Gs of normal force. Finally, from the crest (D) to the bottom of the hill (E), the track has a parabolic shape, allowing riders to experience a free fall sensation. To begin the hill design, tap on either the top or the bottom of the hill.
First Drop Height = 50.0 m || Loop Design || Top (B)
The one design parameter that is important for loop bottoms is the radius of curvature of the loop bottom. Control of this parameter allows the coaster designer to create the intended rider experience.  There is one safety concern associated with loop bottoms: The acceleration of riders should not be greater than ~40 m/s2. Extreme accelerations result in the rushing of too much blood out of the brain and a subsequent risk of blackout. While not all riders blackout at this acceleration, there would be enough that would to distract others from riding your coaster. Accelerations greater than 60 m/s2 would require a special G-suit. There is a final design consideration that pertains to loops in general. Clothoid-shape loops have a radius at the top that is about 1/3-rd the loop's height and a radius at the bottom that is about 2/3-rd the loop's height.  Click the View Design Data button to view data for a variety of designs.
First Drop Height = 50.0 m || Loop Design || Bottom (C)
First Drop Height = 50.0 m || Hill Design || Top (D)
First Drop Height = 50.0 m || Hill Design || Bottom (E)
First Drop Height = 50.0 m || Loop Design || Top (B)
First Drop Height = 50.0 m || Loop Design || Bottom (C)
First Drop Height = 50.0 m || Hill Design || Top (D)
First Drop Height = 50.0 m || Hill Design || Bottom (E)
Hills create thrill by lifting riders partially or entirely off their seats near the crest of the hill (D). This reduces the normal forces, resulting in 0 Gs in the case of being lifted entirely off the seats. In some extreme cases, the acceleration is so great, that the safety bar pushes down on the riders, creating a condition known as negative Gs. At the bottom of the hill (E), riders experience large normal forces to slow their bodies down and to provide the centripetal acceleration required to negotiate the gentle curve of the track. Riders might experience as much as 3 to 4 Gs of normal force. Finally, from the crest of the hill (D) to the bottom of the hill (E), the track is designed in the shape of a parabola, allowing riders to experience a free fall sensation. To begin the hill design, tap on either the top or the bottom of the hill.
There is two design parameters that is important for loop bottoms - the radius of curvature of the loop bottom. Control of this parameter allows the coaster designer to create the intended rider experience.  There is one safety concern associated with loop bottoms: The accelerations of riders should not be greater than ~40 m/s2. Accelerations that are this high result in the rushing of too much blood out of the brain and a subsequent risk of riders blacking out. While not all riders black out at this acceleration, there would be enough that would to distract others from riding your coaster. At accelerations greater than 60 m/s2, it would require a special G-suit to safely ride the ride. There is a final design consideration that pertains to loops in general. Clothoid-shape loops have a radius at the top that is about 1/3-rd the loop's height and a radius at the bottom that is about 2/3-rd the loop's height.  Click the View Design Data button to view data for a variety of designs.
There are two design parameters that are important for hill tops - the height and the radius of curvature of the hill top. Control of these parameters allows the coaster designer to create the intended rider experience.  There is one safety concern associated with hill tops: The accelerations are downward at the top of the loop. Gravity can provide an acceleration up to 9.8 m/s2. For accelerations greater than 9.8 m/s2, a safety bar must provide the remaining acceleration. As accelerations approach 19.6 m/s2,  a dangerous condition can result. As the upward-moving riders reach the crest of the hill, the force of the safety bar pushes the riders' flesh and bones downward. Yet there is nothing to prevent the upward flow of blood through the blood vessels towards the brain. The rapid rushing of too much blood to the brain can cause some riders to redout. Without a special G-suit, riders are at risk of experiencing the fatal condition of breaking blood vessels in the brain.  Click the View Design Data button to view data for a variety of designs.
There is one design parameter that is important for a hill bottom - the radius of curvature of the hill bottom. Control of this parameter allows the coaster designer to create the intended rider experience.  There is one safety concern associated with hill bottom: The accelerations of riders should not be greater than ~40 m/s2. Accelerations that are this high result in the rushing of too much blood out of the brain and a subsequent risk of riders blacking out. While not all riders black out at this acceleration, there would be enough that would to distract others from riding your coaster. At accelerations greater than 60 m/s2, it would require a special G-suit to safely ride the ride. Click the View Design Data button to view data for a variety of designs.
First Drop Height = 50.0 m || Loop Design || Top
First Drop Height = 50.0 m || Loop Design || Bottom
First Drop Height = 50.0 m || Hill Design || Top
First Drop Height = 50.0 m || Hill Design || Bottom