Frank Mezzatesta
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Walt Disney Imagineering 1983

1983 The Horizons Pavilion

The Ride System
I assume because of Wikipedia some people call Horizons a Dark Ride and an omni-mover ride, both of which are not true. Imagineers never referred to it or any EPCOT Pavilion as a Dark Ride as far as I know, but whatever would you call it so go ahead if you want. An omni-mover ride, like Haunted Mansion has motors mounted to the track and fins on the vehicle (or buggies) that move it through the attraction. Horizons was actually a unique system that had the motors on the vehicles above the guest's heads. The vehicle hung from the track above. The unique part was that since the track went up and down, there were variable speed drives off-board that were set to different frequencies depending on where in the track you were. There was a lot of work to tune the system so that each vehicle's motors would balance the load for that vehicle so that there was not undo forces on the connecting tow-bars.

Why is it so quite?
Usually the audio engineers are stuck with whatever the ride (mechanical) engineers give them and you can notice on many rides the audio is turned way up to drown out the vehicle noises*. This was one of the first rides to use variable frequency drives. The downside of variable frequency drives is they can make the motors "sing" at its modulation frequency typically around 4 kHz. For one of the few times, the audio engineers stood fast and at the first design review gave us all a lecture on acoustics. The louder your stuff is the more we have to turn up the volume to drown the noise out and that is not good! It worked. The ambient noise level on Horizons was one of the lowest of any attraction. Extra soundproofing was designed around the motors. Also if you ever rode Horizons, the suspension and wheel composition was so good there were times in the IMAX theaters when you could not tell you were moving. To me this was excellence in design.

Ride Control
My job was to write the Ride Control software (along with Bruce) for the attraction. Of all the software I ever wrote, this was the simplest as there isn't much to control with this type of ride. It's all one big system with one start and stop interface unlike any Dark Ride or roller-coaster that has 5 to 40 vehicles all independently tracked and controlled.

EPCOT had opened the year before with a system that used a touch screen as the operator's console. This was such a wonderful good idea that we had not used it before and stopped using it after this. OK I am being facetious here. I thought it was adding complexity and failures to something that could be done with like three buttons. Of course having a color display or even a touch screen for system status, etc is wonderful and would be used but after this experiment at EPCOT, the buttons and switches came back. I say this because part way through the project the person that did the touch screen software left and I inherited that work as well. So I wasn't happy about that.

Scene 34
Scene 34, the last scene where you vote on which experience you will, well experience was rather complicated. I wrote the software for those traveling picture frames that moved perfectly in sync with the vehicles. Getting the exact position of the vehicles within 0.1" was tricky as there was no place to mount a tradition rotating encoder. Instead we mounted a fin on top of each vehicle that had a 0.2" slots every 0.4" inches. Two sensors offset by 0.1" gave me a pulse every 0.1". Also there were two sets of sensors so when one set was in the gap between vehicles the other was reading the next vehicle. There was a reflective stripe that a sensor told me the exact start of each vehicle. This was fun because it required a little more software to know which sensor to read when and to create a single stream of pulses. I think I wrote all this to tell a funny story. One day during testing the stripe reading sensor started to flake out. It was hard to get up into its location above the vehicles with the ride running. Too easy to get munched in there. After sometime looking into it I discovered that dust was settling on the reflective stripe that was mounted flat on the vehicle facing upward (it was the only place it would fit). My solution was I asked maintenance for a 4 inch wide paint brush and I mounted it on a swinging arm so that it would brush off the dust as each stripe went by. Well it work so well that we had a mechanical engineer design a high quality arm but it still had a paintbrush on the end. As I was leaving Imagineering in May of 2020 I was looking through my Horizons Maintenance Manual. I had forgotten this but that paintbrush assembly made it into the manual with a picture of it and an explanation of its purpose.

The Video
In those days we used large floor mounted projectors that were all aimed toward the guests. The video was played and then "wiped" across the projectors as the vehicles moved. I knew the exact position of the vehicles that I used to "servo" the position of the picture frames to be directly in front of the guest vehicle. I send this information to the video system that was used to do the wiping of the video. So at any given moment, the video you were seeing could be coming from more than one projector. What we learned was that the colors in these old technology projectors varied slightly from one side to the other so if you looked carefully it was rather easy to see where the seam between projectors were as the color were slightly difference and created a vertical line. I assume if we did this ride today, one way would just be to mount OLED screens in the picture frames so you would get perfectly synced video with perfect color.

So decades before this, the haunted mansion at Disneyland did a similar trick with the ghost riding in your buggy. Those clever Imagineers connected the ride omni-mover motors mechanically to a rotating system of ghosts on a separate track. You get perfect sync without any computers or technology. For Horizons, since the motors were on the vehicles and not the track, that method could not be used.

The Voting System
So onboard each of the 184 vehicles was a computer system that handled all onboard functions. One of those was the voting system that tallied the votes and sent them offboard via an infrared (IR) link similar to a TV remote control to tell us which video to play. Others wrote this software. I mention this only to point out technology in those days. Today this would be wireless and we would download new firmware (software) via this wireless link. In 1983 each onboard computer had an EPROM memory chip. To update the firmware, someone would have to take the back off each vehicle to gain access to the computer. Then take the cover off the computer and unplug the EPROM chip and plug in a new one. Oh I forgot, after writing the software change, you had to "burn" 184 copies of the software on 184 chips. I felt good that my system for scene 34 had only one chip in a wall mounted computer in that scene. It took like one minute to burn a new chip and one minute to install it.

The Character Police Show Up
When EPCOT was built and for a number of years later, there were no classic "Disney characters" anywhere in the park. No walk around characters, none in any attractions, and none for sale in the shops as far as I know. There was all the new stuff like the SMRT-1 plush and Mr. Broccoli from Kitchen Cabernet to name two I own. Well in one of the scene (I'm a ride guy so I can't tell you its name or scene number) there was a Winnie the Pooh floating in space. I don't think anyone at the time, including the Imagineer that put it there thought much of it. If that person is reading this email me the real story. Well one day near Opening I heard that Winnie the Pooh was out and generic bear was now in. The character police showed up and said we can't have Winnie the Pooh at EPCOT. When I tweeted about this I discovered that the publicity shots used had Winnie the Pooh so they must have taken that picture before the last minute change out.

Side Note on character police
Five years later I tried to put a Mickey on the new tower console for Space Mountain Disneyland and was told I needed permission from some group at the Studio. You hear stories how Disney goes after daycare centers with Disney characters painted on their walls. Well this was so funny that within the company they treat us the same way. Well why do you need Mickey on this console? (we don't, we just thought it would be fun). Who sees this? (only cast members running the ride). Well you have to use these exact colors and he has to... well I forget all that they said but it was a long list. All I know was we could not meet all their requirements so we just used the Space Mountain logo and didn't ask anyone for that permission.

GE as a Sponsor
Some sponsorships are actually a problem for Imagineers like me. Sperry was a sponsor for EPCOT and we had to fill out a form and submit it for approval anytime we did not use a Sperry PC. We needed the cutting edge PCs for much of the work and Sperry wasn't that. GE was different, first we didn't seem to have such a hard time using other products because GE didn't require this form and actually GE made some wonderful things that we liked using their products. With sponsorship we had a GE liaison which would get us access to GE engineers that others could never get to. The variable frequency drives for Horizons were GE and we had GE engineers there to help install them. I called on the liaison for some very special custom motors for a development project years later. This was great!

Why did Horizons closed?
I don't know. I would think someone would have told us and maybe they did and I wasn't paying attention.

In Conclusion
I didn't realize this until recently, but I think Horizons was the best Pavilion EPCOT ever had. I would put maybe the Living Seas Pavilion next. At the bottom I put Wonders of Life.

*A good example is Splash Mountain WDW. I had the pleasure of riding it many times during testing with very few boats on the ride. You could hear everything perfectly. The audio engineers did such a wonderful job balancing the audio and the quality was great as well. As we added more boats just before opening, the splashing of the water from more and more boat coming in behind seemed to drown out the audio. Yes the audio levels were then turned way up but now, to me, it was just loud music. This was the exact example the audio engineers on Horizon's gave us. When you ride guys make too much noise all we can do is turn up the audio level.

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