How Disney's Tower of Terror Works

This video is brought to you by NordVPN. Stay protected online by visiting NordVPN.com/ArtofEngineering for 75% off a 3-year plan. Link below. The Twilight Zone Tower of Terror at Disney's Hollywood Studios is often considered the best thrill attraction to ever come out of Disney Imagineering. The attraction seamlessly combines a 13-story drop

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with immersive, dark elements, all tied together with detailed storytelling. The attraction was considered an engineering marvel when it opened in the summer of 1994, and while it may not have some of the advanced technologies that are common in more recently built attractions, it is still an impressive achievement even by today's standards.

The Tower of Terror was such a hit for Disney that it was replicated three separate times: at California Adventure in 2004, at Tokyo DisneySea in 2006, and at Walt Disney Studios Park in Paris in 2007. The Tokyo version used a different theme and story. compared. to the other 3

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s, and I personally find it to be the most aesthetically pleasing of the 4 attractions. In 2017, the California version re-themed the Guardians of the Galaxy film series, which included the addition of animatronics and large screens for scenes from the show, however the overall mechanics of the ride remained unchanged. The first Tower of Terror in Orlando and the most recent installation at Disneyland Paris maintain the Twilight Zone theme, which is based on the classic television series that aired from 1958 to 1964.

The four Tower of Terror attractions are all similar in concept, however, the original Hollywood Studios version features a unique ride system that is much more complex than the others and offers an experience that can't be found anywhere else. The tower portion of the amusement building is 60.7 m high and houses two 48 m high elevator shafts where the drop sequences take place, along with a large mechanical room above the shafts for the elevator motors. . The rear of the building is approximately half the total height at 32.0 m high and contains the dark attraction component of the attraction along with queues, loading and unloading areas, control and maintenance rooms, and the gift shop.

There are 4 elevator shafts located at the rear of the attraction, and these connect to the main drop-off shafts via horizontal walkways on the first and fifth exhibition floors. After passing through the hotel lobby, the library pre-show and the boiler room, they board one of the 4 rear elevators on the second floor. At this point, it appears that the elevator car is the ride vehicle itself, but guests are actually boarding a semi-autonomous vehicle that is positioned inside the elevator car. Travel vehicles are loaded into the first floor elevators below the passenger loading area and are held in place by a locking mechanism on the floor of the elevator car so that they do not move as the elevator moves. .

Once the passengers have boarded, the journey begins by taking the elevator to the first stage of the show. For the two inner wells, the show scene is located on the third floor, and for the two outer wells, the scene is located on the fourth floor. The show's four scenes are identical, but they are shifted this way to conserve space. When the elevator doors open, passengers see a long hallway where 5 hotel guests seem to appear out of nowhere. The figures then disappear in a burst of electricity as the hallway darkens to reveal a single window in a field of stars.

This scene is achieved with two main techniques that Disney uses quite frequently: forced perspective and an optical illusion known as Pepper's ghost. The corridor opening is full-size, but the walls, floor and ceiling are sloping inward, so that the height at the end is only about 1.2 m. This makes it appear much longer than it actually is seen from the inside. The wall at the end of the hallway is a rear projection screen with a projector placed on the opposite side. At the beginning of the scene, a normal wall with a window is projected on the screen, but the wall fades from the image when the lights go out to give the illusion of a window floating in space.

At the front of the hallway, just behind the first arch, is a large glass panel oriented at a 45-degree angle that spans the entire width and height of the hallway. This aligns with a second perpendicular hallway where another rear projection screen is hidden out of view. The 5 hotel guests are projected on this screen, and the image is reflected in the glass making them appear in the middle of the hallway. This illusion is known as Pepper's ghost and is the same effect that was used for the Haunted Mansion ballroom scene. After the ghostly figures disappear, the projection screen slides out of the hallway to reveal the fiber optic cables used to create the star field.

Many of the hallway walls are made of fabric, and fiber optic cables are hidden throughout the show scene behind the walls, as well as inside the elevator car. When the TV is darkened, the light from the cables shines through the meshes and the cables in the perpendicular hallway are reflected in the glass to make the star field appear three-dimensional. After the corridor scene is completed, the elevator rises to the fifth floor, where the attraction vehicle exits into the fifth-dimensional show scene. This scene features a number of visual effects, including a second star field achieved by two large mirrors with fiber optic cables hidden behind them.

The mirrors are oriented at an angle to each other in a V shape and, as the vehicle approaches, they move apart to allow it to pass. Although there are 4 freight elevators and 4 rider show scenes in the amusement building, there are only two 5th-dimensional scenes on the 5th floor. The four freight elevators are arranged in pairs, with each pair connecting to one of the main drop shafts through a single show scene. Horizontal movement for this portion of the ride uses a trackless system where semi-autonomous vehicles navigate across the fifth floor from one elevator shaft to the next.

The vehicles are known as wire-guided AGVs or automatically guided vehicles and are equipped with sensors that travel close to the ground surface. There are cables installed in the floor that are used to transmit radio signals to the vehicle, and the vehicle is programmed to follow the cables similar to a line-following robot. The signals can also be used to control the speed, direction and orientation of the ride vehicle as it travels along the predetermined path. If the vehicle loses power and radio signals go out, or if something falls to the ground and covers a wire, the vehicle will stop automatically.

The guide-by-wire system can be quite sensitive and is a major cause of ride downtime. Once the vehicle exits the fifth dimension scene, it rides into an elevator car in the drop shaft for the main drop sequence. The elevator cars here are similar to those used in the 4 loading shafts, and also have a locking mechanism to secure the vehicles in place. The ride has 4 pre-programmed drop sequences it can run and the computer selects one at random for each ride. Each sequence consists of a series of different falls and throws towards the tower, with a complete fall from a height of 39.6 m, or approximately 13 stories.

At the top of the attraction, the elevator doors at the front of the tower open, giving guests an aerial view of Hollywood Studios. The two drop shafts actually extend about 8m above this point inside the tower, but the top portion is not used during the drop sequences. A certain distance is also required to safely stop the elevator car and transport vehicle at the bottom of the tower, so the maximum fall height that passengers experience before braking is only about 27.4 m. . The transportation system used for the drop sequences is based on the traditional traction elevator and is not that different from an elevator that you would find in a normal high-rise building.

The system was designed by Otis Elevator Company and uses two giant induction motors to accelerate passengers up and down, reaching a top speed of approximately 63 km/h. A motor sits above each elevator shaft in a machine room at the top of the tower, and each weighs nearly 60 metric tons and can generate 2,000 hp. Each motor is connected to two cable drums in series and there is 1 solenoid brake at the end of each drum for a total of 4 brakes per elevator. Two steel cables are wound onto the first drum and extend down through the floor where they connect to the top of the elevator car, which travels along rails that are attached to the walls of the shaft.

A single cable is more than enough to support the entire weight of a car along with a fully loaded vehicle, but two cables are used for added redundancy. Two additional steel cables are wound on the second drum in the opposite direction and attached to a counterweight that is used to compensate for the weight of the elevator car. The counterweight rides along its own set of rails within the shaft and weighs about as much as a single elevator car with an empty vehicle, so the motor only needs to supply enough power to raise and lower the weight of the passengers. .

Two more cables extend from the bottom of the counterweight and pass around a compensation pulley at the bottom of the shaft before connecting to the bottom of the elevator car. This closed loop allows the motor to pull the elevator car downward, resulting in faster acceleration than free fall. When the engine rotates in one direction, the car is dragged up from above, and when it rotates in the opposite direction, the car is dragged down from below. The result is an intense experience, unlike any other elevator, in which users experience total weightlessness one moment and are pushed back into their seats the next.

But like any normal elevator, the Tower of Terror has a number of redundant security systems that keep guests safe. First, there are the 4 solenoid brakes on the cable drums that are used to control the speed of the elevator. Each brake has 2 arms with friction pads that are held against the drum by a pre-loaded spring. There is a solenoid at the top of the brake, and when electricity flows through it, the resulting electromagnetic force pushes a plunger outward, separating the pads from the drum. When the flow of electricity is cut off, the electromagnetic force stops and the spring pushes the pads against the drum.

The friction between the drum and the pads slows down the drum and stops the elevator car. This design is fail-safe because the brakes are always active in their default state when the solenoid is off and will stop travel automatically in the event of a power outage. If the brakes were to fail, then a mechanical speed control system in the elevator car would activate emergency friction brakes that attach to the elevator's guide rails. There is also a similar speed control system on the counterweight, so both the counterweight and the elevator car can be stopped by the emergency brakes.

In the unlikely event that both steel cables supporting the elevator car were to break, this would also activate a set of emergency brakes to prevent the car from falling down the shaft. If all of these safety mechanisms were to fail simultaneously, which is extraordinarily unlikely, then the falling elevator car would create a cushion of compressed air at the bottom of the shaft that would help break the fall. There are shock absorbers installed at the bottom of each gap that would also help slow the fall; However, these are not designed to catch an elevator car in free fall.

Fortunately, this has never happened on any of the Tower of Terror attractions, thanks to an oversized design and redundant safety systems. While we're on the topic of security, I want to take a moment to talk to you about today's sponsor, NordVPN. Just as thrill rides have layered security systems to keep you protected at the theme park, NordVPN gives you an extra layer of security to keep you protected online. When you connect to the Internet with a VPN, all of your traffic passes through an encrypted tunnel that prevents your Internet Service Provider and other third parties from observing and tracking your online activities.

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After the attraction has completed its descent sequence into the drop shaft, the elevator moves to the first floor where the attraction vehicle exits the elevator in reverse. The vehicle reverses to the unloading area and turns 90 degrees to allow guests to exit onto the unloading platform. While the vehicle is in this position, an inductive charging system in the floor is used to charge the onboard battery in the same way you might charge a cell phone on a wireless charging pad. This is the only time during the entire driving cycle that the vehicle is stationary on the ground and is therefore also the only time that the battery can be charged.

The battery provides the vehicle with sufficient power for its communication and autonomous driving functions, and this is one of the reasons why there is no audio or lighting on board either vehicle. Instead, all of the attraction's audio and lighting systems are located within the show scenes and inside the elevator cabins. Once all guests have unloaded, the attraction vehicle moves to the back of the building, where it boards one of the 2 freight elevators at the halfway point and is raised to the loading platform for the next group. of passengers. . Since there are 2 freight elevators paired with each drop-off shaft, each half of the attraction can accommodate 4 attraction vehicles operating at any given time: 1 on the loading dock, 1 on the show scenes, 1 on the drop-off shaft. descent and 1 on the unloading platform.

This means that a total of 8 vehicles can tour the attraction at a time, giving a total tour capacity of almost 2,000 visitors per hour. And since the two halves of the ride are independent of each other, one side can often operate on its own when attendance is low or when the other side is down for maintenance. This attraction system makes the Tower of Terror very efficient; However, Disney decided to make design changes to the California, Tokyo, and Paris versions to further increase capacity and reduce downtime. Since wire-guided AGVs were a common source of reliability issues, they eliminated the need for autonomous vehicles by eliminating the 5th dimension scene and the 4 freight elevators.

Corridor scenes that were previously connected to the freight elevators were moved to the drop shafts and a second show scene was added on the fifth floor. The scenes vary quite a bit between attractions, especially with the recent conversion of the California Tower to Mission: Breakout, however they all originally featured similar effects such as forced perspective and Pepper's ghost, as well as other mirror tricks. Since the new attraction design does not use AGVs, the loading platforms had to be relocated to the drop shafts, but here the attraction vehicles are loaded and unloaded outside the elevators. Once passengers have boarded a vehicle, a mechanical grab moving along a track pushes it into the elevator car, and once the ride is complete, the grab takes the vehicle off the elevator to unload it.

A second loading area was also added one level below the first, allowing one vehicle to be loaded while the second performs the travel cycle. The elevator system itself is essentially identical to the original used in Orlando, but here it is used for the main drop sequence as well as moving between scenes of the show. Since each drop axle can only accommodate 2 attraction vehicles in this configuration, a third axle was added so that a total of 6 vehicles can ride the attraction at once. This greatly increased the overall capacity of the attraction and also allows two shafts to remain open when one is closed for maintenance.

It can't be argued that Disney's second version of the Tower of Terror has a much more streamlined design compared to the original Hollywood Studios version, however, it doesn't offer the same immersive experience that you can only find in Orlando. While Tokyo may have the best aesthetic and California may have the most compelling history, there's still something special about the journey through the Hollywood Tower Hotel and the crossing into the fifth dimension that Imagineers simply haven't been able to replicate. Hello everyone, I hope you enjoyed today's video about Disney's Tower of Terror. Let me know what your favorite Disney attraction is in the comments and I'll try to make a future video on the engineering behind it.

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