Keeping Riders Safe: A Reverse Engineering of Block Brakes on Roller Coasters

Have you ever been in line, waiting for your favorite coaster, wondering how the outgoing trains don’t collide as they whizz and soar around the track? Block brakes are the stopping mechanisms commonly utilized in Block Sections- otherwise referred to as “blocks”. Block sections are comprehensive systems that ensure trains don’t collide into one another on roller coaster circuits.

Contrary to what some might believe, the overwhelming majority of contemporary roller coasters don’t include on-board braking systems. Instead, ride engineers place Block sections around roller coaster tracks in order to ensure that vehicles can run on the same track simultaneously.

Whether you're a curious fan wondering how roller coaster systems keep riders safe, or an experienced engineer hoping to learn more about the system's parts and inner workings, this case study aims to provide an in-depth analysis of the system that revolutionized the theme park industry.

Block Brakes have pioneered the way in which modern ride designers tackle the issue of ride capacity. In loading areas, as one train navigates throughout the track, other trains can load guests in a timely manner at the station. Behind control panels, ride operators can keep track of each train’s position at any given time, and thus tell when the track ahead is clear. Throughout the track, Block Brakes can slow trains down and even stop them completely. Pull down your shoulder restraints because we’re in for a smooth ride exploring the history and science behind blocking sections!

The History of Block Sections

Early Developments- Locomotive Beginnings

Block sections weren’t always digitized, as according to a 1907 report from the Interstate commerce commission, Block sections started out as a process or methodology made possible by the use of electric bells, telephones, signal apparatuses, or telegraphs.

In July of 1870, Thomas Halls patented a design for a signal apparatus that would allow for railroads to pass along the same tracks at separate times while warning other trains of its position. The device featured a lever that, when triggered by passing trains, would send a current to the opposite end of the block section and light up a “danger” signal, warning incoming trains not to move ahead. This invention was stationed in Connecticut, and systems like it were eventually adapted by railroad companies across the country.

(Figure 1.1)- Electromagnetic Signal Apparatus patent for railroads, registered by Thomas Halls in 1870. Image courtesy of Connecticut History.

This invention greatly reduced the number of train collisions during this time period. Trains wouldn’t enter a block system without a visible confirmation from an engineer that the track was clear, which allowed for more precise communication between locomotives. In earlier time-interval based systems, locomotives were prevented from entering a specific section of track until the train ahead of it cleared the same section of track.

This system held many inefficiencies, as it utilized unreliable communication between stations for confirmation. The lack of automation was costly and inefficient, and it’s no surprise that the far more advanced brake sectioning system was developed in its place. Through the development of signal apparatuses (Fig 1.1) alongside other technological innovations, brake systems soon gained traction in the world of locomotive design.

Roller Coaster Adaptation

(Figure 1.2)- A brake man operating the historic Rutschebanen, a coaster found in the Bakken theme park. Image courtesy of Theme Park Review. 

Around the time period brake sections were first being adopted by locomotive companies, roller coasters were slowly growing in population around the globe. Due to an expansion of the middle class causing a heavier reliance on leisure and entertainment, amusement parks as a whole grew in demand.

Leading up to the early 20th century, roller coaster operations often relied on brake men who were stationed on the ride vehicles themselves. These employees used manual breaks in order to control the speed and stopping of trains, and mainly operated through the use of levers. This style of speed control put limitations on the extremity of the roller coaster track layouts, as brake men needed to be able to abruptly stop the train at any point during the ride’s duration. Features like inversions and steep drops weren’t widely adapted at this time due to these limitations.

Furthermore, employing someone to continuously sit on every coaster and maintain awareness of other carts on the track was costly and lacked advantage. This problem- alongside capacity limitations and the restriction of thrill- were some of the initial issues that led to the introduction of brake systems on roller coaster tracks. 

As park owners looked for ways to increase capacity, lower operating costs, and technologically evolve, brake systems were altered for roller coaster circuits.

One of the first roller coasters to adopt a computerized blocking system was Matterhorn Bobsleds in 1959 at Disneyland Park. Sensors stationed throughout various locations were embedded into the track’s design, allowing for the roller coaster to move trains through the attraction with a lower risk of collision. The success of this system in early designs led to a large expansion of the system; today, block brakes remain a widely adopted form of roller coaster technology.

A Reverse Engineering of How Block Brakes Work

Block sections are the main way that ride engineers prevent roller coaster trains from colliding with one another. A block section that’s positioned during the middle section of a ride’s layout is called a “Mid-course break run”. The vast majority of modern coasters with multiple trains on a single track layout utilize this system, but how does it operate? 

Ensuring Smooth Operation: Programmable Logic Controllers

(Figure 1.3) A PLC control panel that outlines a ride’s layout and showcases a PLC’s functionality through sensors and lights. Image courtesy of Library.AutomationDirect

Block Brakes act as invisible walls that prevent coaster trains from entering a portion of the track before it’s clear, and they monitor the position of each coaster train through the usage of a computerized system. The most common system is a PLC (Programmable Logic Controller).

PLCs use sensors placed around the track in order to maintain knowledge of each train's position at any given moment. The PLC manages emergency stops, variable frequency drives (ensuring the operation of electric motors), brake system verification, air compressor systems, and many other variables.

PLC’s verify that trains clear sections of track through the monitoring of pressure switches. The pneumatic and electromagnetic functionality of block brakes are continuously monitored by PLC’s, and failures- such as problems with air pressure- can lead to alarms going off that shut down the ride.

PLC’s remain one of the most vital parts of roller coaster operation. They’re the complex technology that ensures visitors remain safe on board their favorite attractions.

Different types of Block Brakes

Fin Breaks- Absorbing Kinetic Energy and Utilizing Friction

(Figure 1.4) Fin breaks on a wooden coaster. Image courtesy of Park Vault.

Fin Brakes (also referred to as friction brakes) are some of the most commonly found stopping devices on roller coasters. Whether they’re stationed during a mid course break run to slow trains down, or the track as trains enter a station, Fin Brakes are an extremely helpful tool for slowing trains down- and ensuring rider safety.

Unlike Magnetic brakes, fin brakes utilize friction in order to be able to stop trains completely. This technology is especially useful in cases where the ride operator must initiate an emergency halt.

The way Fin Breaks work is by having two brake pads sitting next to each other on a section of track, simultaneously opening and closing in order to control the speed of ride vehicles. As trains pass through the brake pads, a metal fin located underneath the trains passes through the clamp-acting brakes.

(Figure 1.5) IR camera mapping of the thermal energy absorbed by fins during a brake run on a roller coaster. Image courtesy of Anne-Marie Pendrill, Magnus Karlsteen, and Henrik Rödjegård

This small gap- left in between fully open brake pads- allows for trains to pass through unaffected, but they can also slow down the speed of trains by closing or tightening. With resistance created by friction, Fin brakes slow the metal fin of the train down. The way friction is created is by absorbing the kinetic energy of the fast moving train. The kinetic energy is transferred to the fin brakes in the form of heat, which can leave these clamping metallic pads extremely hot (Fig 1.5).

Fin Brakes are programmed to remain closed with the use of heavy steel springs, in case of a power failure. In order for the brakes to open and for trains to pass by unaffected, the brakes require air pressure to open (which is controlled and released by the PLC’s that monitor the train positions). Because of the friction created on these brakes, they require frequent inspection due to wear and tear, and they often need to be replaced. Also, in order to be effective, Friction Brakes require a long and straight path of track in order to efficiently stop a moving train.

Magnetic Brakes- a Field of Force

While Fin Brakes rely on the absorption of kinetic energy and friction in order to slow down or stop moving trains, magnetic brakes instead rely on eddy currents and electromagnetism.

(Figure 1.5) Magnetic field creating an opposing force to a ride vehicle. Image Courtesy of Penn State TPEG.

PLC’s monitor electric currents and fields that generate through Magnetic Brakes. When a conductor, or in this case the metal fin located under each coaster train, passes through the magnetic field, opposing forces slow down the conductor. According to Lenz’s law, eddy currents generate magnetic fields that spin in the opposite direction than the magnetic field that caused it to spawn, and are therefore inverse responses to the original magnetic field. This opposition to magnetism is what causes the train to slow down (Fig 1.6)

Magnetic brakes allow for roller coaster trains to be slowed down without any physical contact. This is a huge advantage, as they require less maintenance than friction brakes. 

Magnetic breaks, instead of relying on permanent magnets, often utilize electromagnets that can be more easily altered than permanent magnets; with the use of electric current, braking forces caused by coming into contact with a conductor can be dialed up or dialed down. Magnetic Brakes are often used with Fin Brakes in case of a malfunction.

Lift Hills- Unexpected But Useful Blocking Tools

(Figure 1.6) Riders being evacuated from the top of a lift hill at Cedar Point. Image Courtesy of KCRG News.

Lift hills, through the responsive programmable computer logic systems, can also be a helpful vessel for block sectioning. For instance, if the train nearest to the lift hill hasn’t cleared the following block brake upon a train’s ascension to the top of the lift hill, the chain can be slowed or stopped until the PCL system is cleared. In case of an on-ride breakdown or emergency halt of operations, evacuations of trains can take place on the lift hill (Fig 1.6).

Most lift hills feature a staircase attached to the incline slope in preparation for these malfunctions. Furthermore, sensors are placed on lift hills in order to monitor the trains position, and therefore lift hills are often a vital part of block sectioning. 

Safety System

To ensure safety on roller coasters, there’s a special type of PLC- named a safety PLC- that continuously collects data from the ride sensors and compares the data with other collected values from sensors in the same region. The reason for this is to ensure that all sensors remain accurate, and to stop the ride immediately if there’s a system error. In case of an emergency occurring on a roller coaster, Block Brakes are vital in ensuring that vehicles remain stopped.

(Figure 1.4) A simplified model of dual processors working within a safety PLC. Image courtesy of Kleist Robotics

Safety PLC’s utilize a dual processor system on roller coasters while continuously checking variables (Fig 1.4). If these two verification systems disagree, they send a signal to the general PLC that immediately holds the roller coaster at the next available block braking section.

A common example of this is on-ride breakdowns and malfunctions where guests exit the track through walkways commonly attached to mid-course brake runs. In a case where block brakes themselves malfunction, the system would be alerted through these Safety PLCs. An example of this could be where an air compressor malfunctions and isn’t able to effectively stream air from a tank in order to create friction (between the two metal plates that the roller coaster runs over). The Safety PLC would be alerted of this system malfunction and immediately halt ride operations.

Every output on a PLC is verified through two relays. If either of these relays were to malfunction and close the loop on the system, the other relay is able to stay open and successfully bring the ride to a complete stop. This allows for the programming to always run exactly as the engineers intended it to.

For more information on the general aspects of PLCs and Safety PLCs specifically, I recommend checking out Kleist Robotics’ YouTube channel, but this article is aimed at exploring the aspects that impact Block Brakes specifically. 

Conclusion

Block Brakes are vital to maintaining rider safety on roller coasters. Whether it's PLCs continuously monitoring track-based sensors or Magnetic Brakes creating force fields strong enough to slow down high speed trains, many intricate systems are in place to slow trains down in case of emergencies.

Thank you for taking the time to read through my first case study on Block Braking systems! My name is Henry, and I'm an aspiring theme park engineer who remains fascinated by the technology of immersive rides. I'll be continuously uploading new case studies to this blog, so make sure to stay tuned for my next release!

If you have any recommendations for a system to analyze next, please leave a comment under this post. Thanks again!

Sources Used

“Compressed Air and Roller Coasters.” Quincy Compressor, Quincy Compressor,  https://www.quincycompressor.com/blog/compressed-air-and-roller-coasters/. Accessed 28 Mar. 2026.

“The Evolution of Roller Coaster Design.” BYU Design Review, Brigham Young University,  https://www.designreview.byu.edu/collections/the-evolution-of-roller-coaster-design. Accessed 28 Mar. 2026.

“Electromagnetic Braking in Industrial Applications.” AZoM, AZoM.com,  https://www.azom.com/article.aspx?ArticleID=18334. Accessed 28 Mar. 2026.

“Electromagnetic Propulsion of Roller Coasters.” PSU Theme Park Engineering,  Pennsylvania State University,  https://www.psuthemeparkengineering.com/what-we-know/electromagnetic-propulsion-of-roller-coasters. Accessed 28 Mar. 2026.

“Magnetic Brakes.” University of Gothenburg Physics Department,  University of Gothenburg,  https://physics.gu.se/LISEBERG/eng/magn_brakes.pdf. Accessed 28 Mar. 2026.

“Railroad Signaling.” Encyclopaedia Britannica, Encyclopaedia Britannica, Inc.,  https://www.britannica.com/technology/railroad/Signaling. Accessed 28 Mar. 2026.

“Riders Evacuated from Cedar Point Roller Coaster near Top of Hill.” KCRG,  3 Aug. 2023,  https://www.kcrg.com/video/2023/08/03/riders-evacuated-cedar-point-roller-coaster-near-top-hill/. Accessed 28 Mar. 2026.

“Roller Coaster (Short Video).” YouTube Shorts, YouTube,  https://www.youtube.com/shorts/zLguESzmC4s. Accessed 28 Mar. 2026.

“Roller Coaster (Video).” YouTube, YouTube,  https://www.youtube.com/watch?v=VvtpaBxSv7U. Accessed 28 Mar. 2026.

“Roller Coaster AutomationDirect Case Study.” AutomationDirect Library, AutomationDirect,  https://library.automationdirect.com/roller-coaster-automationdirect-case-study/. Accessed 28 Mar. 2026.

“Roller Coaster Positioning.” Turck Inc., Turck Inc.,  https://www.turck.us/en/rollercoaster-positioning-605.php. Accessed 28 Mar. 2026.

“Thomas Hall’s Electric Block Railroad Signal.” Connecticut History,  Connecticut Humanities,  https://connecticuthistory.org/thomas-halls-electric-block-railroad-signal-today-in-history/. Accessed 28 Mar. 2026.

United States Government. Serial Set No. 5072. Government Publishing Office,  https://www.govinfo.gov/content/pkg/SERIALSET-05072_00_00-109-0342-0000/pdf/SERIALSET-05072_00_00-109-0342-0000.pdf. Accessed 28 Mar. 2026.

“What Is a Variable Frequency Drive?” Danfoss, Danfoss,  https://www.danfoss.com/en/about-danfoss/our-businesses/drives/what-is-a-variable-frequency-drive/. Accessed 28 Mar. 2026.

“Wooden Coasters Braking Systems.” Park Vault,  27 Aug. 2014,  https://parkvault.net/2014/08/27/wooden-coasters-braking-systems. Accessed 28 Mar. 2026.

“Brake Run.” Wikipedia, Wikimedia Foundation,  https://en.wikipedia.org/wiki/Brake_run. Accessed 28 Mar. 2026.

“Theme Park Review Photo.” Theme Park Review, Theme Park Review,  https://www.themeparkreview.com/parks/photo.php?pageid=27&linkid=4616. Accessed 28 Mar. 2026.