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A Friday Visit with Jim Korkis: Twilight Zone Tower of Terror

By Dave Shute

Welcome back to Fridays with Jim Korkis! Jim, the dean of Disney historians, writes about Walt Disney World history every Friday on


By Jim Korkis

While variations of the Tower of Terror attraction have been at four different Disney theme parks worldwide, one of the things that makes the Walt Disney World version unique among them is the inclusion of the horizontal journey through the Fifth Dimension experience.

Every week the Twilight Zone television show began with host Rod Serling telling viewers that, with the key of imagination, one unlocks the door to another dimension.

The idea of another dimension was shown in the Little Girl Lost episode (March 1962) where a little girl named Tina falls into another dimension through the wall behind her bed. The premise for the Tower of Terror attraction is that the ill-fated elevator passengers have fallen into a new dimension and have been trapped there never aging for decades. They are not ghosts.

In the WDW attraction guests’ elevator leave the lift shaft and pass through the Fifth Dimension where they get a glimpse of the 1939 passengers motioning them to go deeper and join them. The elevator then goes into another lift shaft.

The Tower of Terror actually employs more than one type of vehicle in order to enable riders to leave the elevator shaft and pass through the Fifth Dimension. Guests sit in Autonomous Guided Vehicles (AGVs), which rise up to the corridor scene in a Vertical Vehicle Conveyance (VVC).

At the time work began on the attraction, United Technologies was the sponsor of the Living Seas pavilion at Epcot. UT owned a subsidiary, Otis Elevator that had pioneered the development of the safety elevator in 1852 that would lock it in place if the ropes failed. Originally, because of their reputation, they balked at the idea of being involved with an “unsafe” elevator but were persuaded it would be good publicity.

The self-guided vehicle was assigned to Eaton-Kenway, a manufacturer of computerized pallet drivers for automated warehouse inventory transport. There were challenges getting both systems to work in tandem.

When guests reach the Fifth Dimension corridor, the AGVs exit not on a track like a traditional dark ride vehicle but are guided by wires under the floor. This technology was originally developed for the vehicles in Epcot’s Universe of Energy attraction and The Great Movie Ride.

When they reach the far end of the corridor, they lock into another vertical motion cab, which handles the actual drop sequence.

The AGVs are powered by onboard batteries, which are charged while riders are unloading. At any one time, up to eight of these vehicles could be circulating around the Tower of Terror’s ride system. Ten were originally built.

While there really are two drop shafts on the Tower of Terror, there are actually four elevators that lift the AGVs from the boarding area up to the Fifth Dimension scene – two of these merge into a single corridor scene. This enables the ride to have an increased capacity.

Unlike other amusement park drop rides like Magic Mountain’s Freefall, guests are not in fact being pulled down by gravity. In fact, they are moving faster than the speed of gravity to a top speed of 39 miles per hour.

Once the AGV vehicles are locked into the Vertical Vehicle Conveyance (the elevator housing), they are pulled by cables connected to two enormous motors which are 12 feet tall, 35 feet long and weigh a massive 132,000 pounds. These pull the VVC up and down.

When the attraction was going through the test and adjust phase, it was found that the VVC was being pulled down so rapidly that it was compressing the air at the bottom of the shaft and blowing out the walls, so adjustments had to be made.

Besides the Fifth Dimension scene, other differences unique to the WDW version are some particular Twilight Zone artifacts and references, but that would need another column to cover!

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Thanks, Jim! And come back next Friday for more from Jim Korkis!

In the meantime, check out his books, including his latest, Disney Never Lands, and about planned but unbuilt concepts, and Secret Stories of Walt Disney World: Things You Never You Never Knew, which reprints much material first written for this site, all published by Theme Park Press.



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