Read Haunted Mansion “A Little Tech Stuff” postings from WDW maintenance man

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Back in the early 00s, one of Walt Disney World’s long-time maintenance men joined the discussion boards under the name wdwcaretaker and started relaying details of the inner workings of The Magic Kingdom’s Haunted Mansion under the heading, “A Little Tech Stuff”. After a short time the system started auto-deleting his message threads so I saved as many as possible. Each was fascinating and detail-rich.


This is the first in a series of Tech Posts which will take you through the WDW Haunted Mansion from beginning to end. Almost everything in this series has already been touched on in previous posts, but some of you have tried to get the old Tech Posts back but they are gone forever. I appreciate your interest.

Let me start out by saying that the Mansion consists of several show elements, among them being the ride system, the audio animatronics, show lighting, special effects, audio and all the related support systems that tie it all into a viable attraction.
To know the Mansion concept, you must review the great information provided by Chef in other locations on this website. I won’t get into that.

I also won’t get to deep into detail because then we get into major boredom for most of you.

This post is mainly a prelude to the technical info to come.

The Mansion is a dark ride, therefore, show lighting is of the utmost importance. The Mansion’s eerie and ghostly appearance is achieved through blacklight lighting. Almost every scene has its blacklighted effects. The Library’s rocking chair and book shelves are blacklighted. The two large spiders are as well.

Every instrument in the Seance circle is blacklighted. In the Banquet Hall, only the Organist and the skulls over the organ are blacklighted. In the Attic scene all the pop-up ghosts and the Beating Heart Bride are also highlighted by blacklight.
The largest scene, the Graveyard uses this lighting effect the most. With the exceptions of the ‘still alive’ figures such as the Caretaker and his dog, the owls, the three cats, the dog at the Mummy and the Ravens, all else in this scene is blacklighted to the max.

Last but not least, Little Leota is blacklighted to highlite her dress.

Where blacklight is not used, white light is. The above mentioned ‘alive’ figures are white lighted as are many animated props such as the ballroom dancers and guests, the Banquet table ghosts and the overhead Banshees. these are used to achieve the Pepper’s Ghost effect in that scene. This effect could not be achieved with blacklighting.
Because the Mercury lamps that provide the light source lose their intensity over time, the Mansion is totally relamped twice per year. This keeps the effect fairly bright all year around and meets show quality standards. Keep in mind also that all the blacklighted show elements must be ‘painted’ with special blacklight reflective paint by our Artist Preparators and must be periodically touched up to regain their original reflectivity.

The blacklights we use are actually several types. The greatest number of them are mercury lamp fixtures which have a built in ballast. these utilize a 100 watt mercury lamp. There are also several fixtures which utilize a 250 Watt lamp. These fixtures are very large, about 14″ in diameter and are designed to illuminate a large area with blacklight, rather than the concentrated lighting achieved with the 100Watt lamps. The smaller lamps are used to illuminate individual figures and props. These lamps come in two types, spots and floods. The spots project a narrow beam on figures such as the pop-ups, whereas the floods illuminate the larger figures from head to toe. The 250s illuminate entire areas, but not as intensely.

The third type is the blacklight fluorescent. These are used mostly for backlighting and are designated as ‘blacklight blue’. The blacklight black lamps are more Ultraviolet emitting than the blues. Whereas the Blacklight blues give the moonlight effect you see on the tombstones in the Graveyard, the Blacklight black lamps are used in very few places which include inside the Flute Player’s tomb and the large spider on the right of the stairs.

As a sidenote, when we remove lamps for disposal, especially the mercury lamps, they are placed in a designated hazardous waste disposal area where they are picked up and disposed of properly in accordance with OSHA regulations. Disney is very conscious of environmental issues and we are required to follow them to the letter.

The only mini-mole used in the Seance scene used to be on the floor shining up at the drapes that hang to each side and to the rear of Madam Leota. They were mounted to the floor down below, but when the new permanent metal grating flooring was put in her pit in place of the cargo netting, those two fixtures had to be eliminated because of checkered shadows they would cast through that flooring.

Mounted behind the ride all along and directly under each hanging instrument shining directly up at them are individual blacklight fixtures and nothing else.

There is one other minimore overhead that shines on the raven which is behind Leota on her chair, but everything else is backlight.

I have what is called a lighting schedule which designates what each light fixture does, what kind it must be, what lamps they must use, what filters or gels are used for lenses. I have the original and updated schedules and nowhere does it call for minimoles on those instruments.

There must be some confusion somewhere, but that is the way it is in the whole show.
The mini-moles are original equipment manufactured by a company named Mole-Richardson. I do not even know if they are around anymore. These fixtures are used extensively throughout the show for white lighting effects. Another type white light fixture called a ‘Brogie’ are used to illuminate the library busts from behind, and all the figures at the banquet table. The Brogies are used mostly to light up figures as needed. The mini-Moles are used for prop lighting except in the case of the stretching room hanging ghosts Which are Mole illuminated.

Oh yeah, a comment was made about the blacklight fixtures being able to turn on and off quickly and the answer to that is no. They require several minutes to reach full intensity.


As we approach the Haunted Mansion at WDW, you gaze upon the scene before you. It is a unique vista of Victorian architecture and modernisms that encompass the area. A sort of clash that seems to blend in well anyway.

To your left is the entrance area where you walk under a canopy which utilizes blue/white overhead floodlamps to give the Mansion’s omnipresent moonlight glow. In front is the Mansion facade. The structure gives the appearance of being on a hill, sort of like the old house in the movie ‘Psycho’. In actuality, the ground you stand on where the outside Hearse is, is the floor level that the ride itself is on. Inside the structure of the building facade are four levels. Below the ground level you stand on is the ‘basement’ area which encompasses the entire ride. This is where all the ride system rails and mechanisms are located, plus electrical and lighting panels as well as the base frame mechanisms for the animation. Also Located on the basement level is my workshop, boat repair shop and the electrical equipment room where all of our audio and other show related electronics are located.

The show’s first scene, the Foyer and Stretch rooms are located immediately behind the facade. The stretching room mechanism goes all the way from the floor level the guests stand on, all the way up to the total height of the facade you see from outside. This is the highest point in the entire building.

The two levels of the Mansion (which is actually a large square warehouse looking building behind the facade) above the the ride is for high ceiling areas like the Banquet Hall and the Graveyard scene. These different levels allow for the ride to travel to different levels, from load, down to the Music room, up to the Corridor of Doors, up again to the Banquet Hall scene and the from the Attic down to the Graveyard and back up again to unload.

The first animation you see will be the Leota Tomstone and the Traveling lights. That will be covered in the next Tech Post sometime during the upcoming week.


Someone on the board had some of my old Tech Stuff postings that he was gonna put back up here for me so that I wouldn’t get too redundant, but I don’t see them so here goes:

Before starting our walk through, I touched on the lighting in the Mansion, and just as important is the audio-animatronics which makes up your show elements.

There are several types of animation in the Mansion. There are animated Figures (Ghosts), animated animals, animated props and show action equipment.

Animated figures consist of the human figures depicted throughout the show, from the Caretaker, to the ghosts, pop-up heads, the Bride to name a few. Animated animals consist of the owls, cats, dogs, and ravens.

Animated props are your moving but otherwise inanimate objects such as rumbling and jiggling tombstones, Seance instruments, conservatory coffin, candelabras, bulging doors and so on.

The show action equipment consists of turntable items such as the Dancers, overhead banshees and bicycle turntable.

All these things together make up what you see when you are on the ride. Many of these things such as the props and show action stuff is motor driven. Various mechanical devices powered by small gearmotors make the movement that you see.

The Animated figures and animals are different. To describe the inner workings of these is to describe basic robotics. You must have a power source, a driving force, a source of show information and the mechanics of the figures themselves.

All of our information which goes to the figures is powered through electronic circuit board cabinets called Remote Terminal Units (RTU). Each and every animated show element is programmed to do specific things. Programmed by WDI engineers and burned into computer chips are the programs for each figure and combined into one overall program for the entire show.

This is stored in Disney’s Digital Animation Control System or DACS as we call it at WDW. From there it is transmitted to the RTU cabinets in the Mansion, and from there the program is distributed to each figure and each function within that figure.
In other words, they all do as they’re told.

The show cycles every few minutes. In other words, the show program runs from beginning to end, then starts over. This goes on all day with only a slight visible hesitation between cycles.

All of this combined with the audio, lighting and projection gives the Mansion its look.

The next Tech Post will deal with the inner workings of Animatronic figures which includes hydraulics, pneumatics and actuators.

Let me do this as an add-on to the Tech Post I just completed so that we can move on later this week. In most attractions, animatronics figures are driven by pneumatics(air) and hydraulics (fluid) power. In the Haunted Mansion at WDW, all such elements are pneumatic as there is no longer any hydraulics in that show.
What makes Caretaker’s body turn or his head nod? What makes the ghosts mouths move when they sing, or lift a glass in salute?

Every animated figure and animal is actually very close in structure to you and i. Each has a skeleton (frame), a brain (program), and appendages that move.
The human figure is always more complex in structure than the animals, but their functions are correct for their species.

These humans and ghosts are designed to have their body parts move with the same exact latitude of a real person.

Mechanically, they cannot twist their bodies, move their elbows or turn their heads any further than you can. Try turning your head from left to right and you get about 160 degrees of movement, more or less. That is the max for the figures. Can’t bend your arm beyond straight, neither can the A1 figure. This is intentional to give the programmers and the figures a real look to work with.

These movements are possible by the interaction of pneumatic ‘actuators’ with the mechanics in which they are integrated.

An actuator is nothing more than a cylinder with a piston in it. To this cylinder are air supply lines at each end. The air direction is changed by a series of valves which shuttle the air to the actuators back and forth according to what the program tells the to do. The piston shaft that protrudes from the cylinder is attached to other mechanisms for that function.

An elbow actuator for example is told to make the arm straight, then bend. To straighten the arm, air pressure is forced into one end of the actuator and makes the piston shaft extend. When this happens, the arm straightens. When the actuator’s piston shaft is told to retract, the valve shuttles the air in the opposite direction and forces the piston to retract and pull the arm to a 90 degre or more angle.

The program will make this function move depending on where the programmer tells the actuator to go and in what direction. This is called ‘tracking’. There are two types of movements with actuators, digital and analog. Digital functions are always on/off. Eye blinks and mouth open/close are digital functions. Analog functions can be made to move from point A to point B and anyplace in between. Head nods and turns, arm movements and the like are analog functions.

To picture an actuator, take the cylinder that raises the back of a dump truck up and down, and on a much smaller scale and that is what an actuator is and does. There are also many types of actuators. Some are spring loaded, and there are rotating actuators to make a function do a turning motion rather than a linear one.

Combine ’em all together in a single program and you have a Caretaker turning, nodding, gawking and moving. You have a flute player playing, a drummer drumming and the beat goes on.

The next installment will be the biginning of our tour.


Secondly, a correction on some misinformation I put out awhile back concerning the doombuggies audio. I said there were 7 separate zones in the ride, in other words, seven separate areas that you enter and your doombuggy begins a different spiel.
Our audio guy Ray read the post and very diplomatically let me know that there were ten zones, not seven, but some of the audio goes from zone to zone with no separation and it sounded like seven to me….dang! I’m an imperfect being Anyway, Ray says originally there were twelve but for whatever reason there are only ten now. Sorry!

A Little Tech Stuff – Show Quality

The most important aspect of any show technician’s job is show quality or as it is otherwise known, show readiness. What you as guests see when you visit a show here on property is the result of the combined effort of several maintenance personnel assigned to that attraction.

Almost all by-the-book maintenance work is done at night after the parks close, mostly on the night (graveyard) shift. I am one of those ‘nightowls’ who resides in the WDW mansion 40 hours each week. In our attraction we have three Ride Show Technicians. Each of us has certain responsibilities within the show. We also have two fulltime ride mechanics and one laborer. One of the three RST’s (Ray) is our audio, electronics and electrical guy. My responsibility is to maintain the animatronics figures, props and mechanisms, show lighting and some of the projection.

I have a partner (Wanda) who recently completed her WDW Apprenticeship program and is learning all the different maintenance requirements in the Mansion with the exception of the ride system itself.

All that having been said, we are all responsible as a team to keep the Mansion looking its best, and all the techs in the other shows have similar responsibilities.
Narrowing this down to the Haunted Mansion attraction will help explain why and how our work is judged. Many years ago, the show that guests saw was directly related to the dedication of those assigned to maintain it. As you can guess, the quality of each attraction was varied, dependant who worked there. Several years ago, I was one of four members of an animation S.W.A.T. team that spent several weeks and months in each show, rehabbing animated figures and props from the beginning to the end of the show we were sent to work in. That worked pretty well, but because members of the team were pulled from other departments in the MK, some areas were short handed and finally in 1987 the team was disbanded and we went back to our original areas.

After that happened, show quality began to suffer. That is when WDI stepped in and organized quarterly reviews of animation, special effects, lighting and projection.
Every three months, an Imagineer from WDI in each category would conduct individual, in depth inspections of each of these four elements. It was like a constant parade. The end result was a show readiness score, by percentage. Each element of each show was expected to score a 95% show readiness review, or questions would be asked. In each case, the spotlight shone directly on us and how we performed our work. Here is what the engineers looked for:

In the Haunted Mansion there were exactly 350 animated functions (there are more now with the Leota Tombstone). An animated function is any specific movement of an object which is designed and programmed into the show. The show readiness percentage was based on how many of those functions were working properly or not working at all. To get a 95% or better score, 332 of those functions had to have no flaws. In the past four inspections, we achieved 100% show readiness, and I am proud of that.
These inspections also included turntables and props and show action equipment. They were all inspected for smoothness of operation, correct tracking with the program, and other like operations.

The show lighting review which WDI conducted consisted of fixtures working or not working, correct lamps used, cleanliness of lenses, proper color gels which were not burned or faded, and most importantly, lamps which had not been left in the fixtures so long that they lost intensity. This is especially important with UV or blacklight lighting which after time, dims the effect.

The special effects review was designed to check items such as the 10X10 projectors used to project the rising ghosts, clouds, mists and even the Piano ghost. These are listed as special effects and not as projectors because they are not ‘film or laserdisc’ projectors such as the Leotas and the busts. There are 21 10X10s in the mansion. Also on the special effects list is the Ectoplasm, the ‘Blowing Ghosts, and the Banquet Hall fireplace among others.

The projection review as previously stated checks the readiness and operation of the 16mm projectors and the Laserdisc projectors at the Singing Busts, which lately have come under much scrutiny.

Each review is scored separately, so we are always under the gun to keep things up. Since 9/11 unfortunately, cutback came to WDI and these inspections have come to a standstill, especially the animatronics inspections. We have had recent lighting and effects inspections but not on a quarterly basis.
Because these inspections have taken a hiatus, the true dedication and work ethic of the maintenance team members in each show will have to be judged by guest comments and feedback. All these behind the scenes reviews are designed to give each guest his/her money’s worth of enjoyment. Knowing the Haunted Mansion team members I work with as well as I do, you who visit can expect a pretty darned good show.

Wow! Talk about a classic ramble.

A Little Tech Stuff, 01/2003

In the wonderful world of audio-animatronics, there are several types and variations on the theme, but our interest lies in the WDW Haunted Mansion. In previous Tech Posts I have covered most of the bases involving animatronics but one area I have neglected is animated props.

As stated, there are several types of animation, Animated Figures (human type), Animated Animals, Show Action Equipment and Animated Props.

Props are the supposedly non-living forms of the Disney attractions. Specifically in the Mansion we are talking about the Attic Batmobiles, the different moving tombstones, the Teeter Totter (that the King and Queen sit on), the Swing (that the Dutchess swings on), the Bulging Vault doors, the Moving Tomb Lids, the brick layer mechanisms (on the right side after the Opera Singers), the Floating Tea Pot, The Bicycle Riders, the Library Books and moving Ladder, the Floating Candelabrum, The moving Piano Keys, all the Corridor of Doors moving parts, The Conservatory Coffin movement, All the Seance Circle floating instruments, the ’empty’ Grandma rocking chairs and so on. I named most of them.

The various turntables except for the Bike riders is classified as Show Action Equipment (dont ask me why the Bikes should be any different, but they are).
So as you can see, moving props are actually as large a show element as their counterpart human ghosts and animal figures.

How do they work?

The reason they are called animatronics is because they move through the utilization of an exterior and interior drive mechanism.

Although they don’t have the more ‘hi-tech’ functions of the actuated figures, they still move with the show and thus are classified with the rest of the AA figures.
The main difference is that props that move are mostly all motor driven. Other animation requires a signal from the DACS program to work according to how they are programmed, so they will not work until the show begins. Motorized props begin their movement as soon as the electrical circuits that feed them is turned on.

There are exceptions (isn’t there always?). In the Graveyard scene, there are three different type tombstones. Static stones, don’t do anything but stand there, motorized stones sway from side to side and that is about it. Then there are the ‘Rumbling Tombstones’ that sway side to side and also move up and down. These are motorized AND actuated. When the power for the show is turned on, these stones will begin swaying, but the actuator involved in the up/down movement will not activate until the signal from DACS tells it to, that way they aren’t all doing the same thing at the same time.
The mechanisms that drive these props are quite ingenious. They range from the more simple side to side movement of the tombstone, to the more elaborate wheel and pully mechanisms of the overhead props in the Seance Circle.

Remember, those are suspended by wire cables, and not only do they rotate but they go up and down at the same time. This type of movement requires the rotating drive motor to work in combination with two separate pulleys which the wires run through from the center axis of the turning mechanism. This causes the ‘Floating Drums’ to rotate and for the two ends of the drums to float up and down like a boat on the ocean.
The two Tables and the Harp in the Seance scene are very large and each requires a fairly hefty ‘Balloon Lift’ mechanism to raise and lower them. By the way, they are called that because the same exact mechanisms raise and lower the many suspended balloons in Small World. Another aside in the same vane, The overhead Banshee mechanism in the Banquet Hall is the exact same mechanism as the Flying Carpet mechanisms in Tiny World.

The floating Candelabrum (2) are motor driven as well and are suspended by two wire cables. Each cable is attached to a separate rotating arm to give it the floating effect.

The Batmobiles in the Attic are shaken by a very ingenious motor driven mechanism which rotates the five arms the bats hang from in a very irregular motion.
Now the Swing and Teeter Totter in the Graveyard are both strictly actuated which is unusual for props. No motors involved, but because they are not living things, they are classified as props. Neither will work until the show program runs.
The prop I did not mention is the new Leota Tombstone. This is a close to an animated figure/prop as you can get. Because I haven’t received the docs on here yet, I would classify her as an Animated Figure, because of the functions she has (eye blinks and turns and face in/out)

And speaking of documentation, as with everything else, exact motor sizes, speeds, gearing etc. must all be in accordance with WDI documentation. NO CHANGES ALLOWED by techs.

So I hope you found this interesting, although I don’t have endless space to go into more details. Besides, there has to be SOME mystery to it all.

Growing older is mandatory, growing up is optional.

A Little Tech Stuff–Other Happy Haunts

One of the things that no one ever discusses involving the Mansion are the other ‘living creatures’ who inhabit the place after hours.

You who read these posts know about what I do, the audio guy and the mechanics and so on. What I have never mentioned are those who take up where we leave off.

About 4:00am, the parade begins. First in will be the Artist Preparators. We have several and each one is assigned certain shows. We techs who work on certain animated items have to tear them down to work on them. When we put them back together, body plastic, skins, clothing and sometimes wigs all need to be repaired or intalled by skilled people in each field.

Several ‘ghosts’ on the left side of the Graveyard scene have skins made of Polyvinylchloride which must be properly cut to be removed from head or hands. Only the APs and a very few of us old guys have been taught to ‘butter’these skins back together. To butter them starts with making sure a single knife cut from the top of a head skin down the back to the neck is made. Then the skin is removed while the head is under repair.

When re-installing the skin, the cut edges of the head skin are cauterized by using a special ‘buttering iron.’ This requires much care or the PVC skin can be ruined.
I can do this but normally call an AP to do the job. They also periodically do show inspections on their own, at least once each week. They do figure painting and many other artistic efforts required in keeping things spiffy.

They just painted the bike figures with blacklight effect special finish and they show up much better. they also do the props such as those that hang in the Seance Circle.
After the APs are through, the Costuming or Wardrobe people are called to redress each figure that needs it. They also do routine checks and change costumes whenever they need replacing. For instance, there are huge lockers under the ride in the Ballroom, where spare costumes for each dancing couple are located. These are not rinky dink costumes either. They are very expensive real clothing items with a combination of buttons, snaps and vel-cro to hold them all together. The two Duelers upstairs in the Ballroom have very nice outfits.

Then come the Cosmetologists, or ‘Wiggers’ as we techs call them.

These folks are responsible for all the hairpieces, beards, moustaches (except mine) in the place. These hairpieces (especially those in HOP and POC) are very expensive and made of real human hair. They will primp and preen these things to the point of rediculousness, but they all look good when they are finished.

The fun part is watching them preen the lady dancers hair. They will spend an hour doing this.

The funny part is when the show starts and the couples begin to spin, the hair sticks out like Pippy Longstocking’s as they go around.

Last but not least are the Custodial people who are in every night, cleaning the attraction. They specialize, some cleaning the ride area and others cleaning the sets.
There are others who are in and out including the Decorating people, Building Maintenance types among them, but they are not regular haunts. They only come when a special need requires them to.

So these are a few of the other ‘Regular’ denizens of the WDW Mansion besides yours truly.

One other aside…..A lot of these folks, especially those from other countries, are extremely paranoid about working in the Mansion. Many orientals have outright refused to work anywhere in the building.

My personal delight is that anyone who enters the place are required to let me know so that I don’t start the attraction up while they are amongst the equipment.

I love to sneak up on them, especially the ladies and scare the bejesus out of them. Life is good!

A Little Tech Stuff…March 2003

Although I have glossed over the operation of AA (audio animatronic) figures in past posts, I thought maybe I would be a little more specific about how they are constructed.

In the past, I have stated that all actuators are either powered by medium of hydraulic oil or pneumatics, Let us deal strictly with our Mansion AAs which are all pneumatic. There are no hydraulics currently in the Mansion at WDW.

We have not one figure in the Manse that has all the functions, but let us assume that the Caretaker does, for instance.

Our Caretaker, like all AAs are built on a steel base frame. A cube of steel 1″ tubing, in which all mechanisms are readily accessible for maintenance.

The AA is attached to this base frame at the feet at the top surface of it, even though his leg tubes protrude down below the stage level of the base frame in order to actuate his body sway, turn and Foreward/back movements. Attached to this base frame below stage level, are the pneumatic support equipment, valves, and wiring that provides electric and programmed signals from DACS that make the figure move.
In order to make him sway side to side, to sway forward and back, and for the body to turn, there are three pneumatic actuators anchored beneath the base frame and attached to it with rod end bearings. The shaft end of the actuators are attached to the AAs leg tubes and because one of his feet is connected to each of these three actuators, the Mansion program for that figure creates a combination of all three movements to give his body life from head to toe.

Above the base frame is the figure that you see. For starters, picture Caretaker as a large stick figure to begin with. Picture this stick figure with all the movable joints of any human being, i.e. knees, elbows, wrists, shoulders, hips, and all functions of the head and neck.

At each of these joints, there are bearings involved to allow the stick figure to move freely in whichever direction the actuators involved allows.

These AAs are designed as follows: If you stand on your feet, straight up, legs stiff and heels together, move your forearm straight at the elbow, then bend it as close as you can to the bicep. This is how much movement the elbow actuator will give that function. Now try with your arm straight again, raising it up as high and as far back as you can. There are limitations that your body structure will not allow you to go beyond. With EVERY SINGLE FUNCTION in an AA figure, those exact same rules apply. What you can and cannot do, the AA can and cannot do

With my next post on this TECH POST subject, I will discuss the different functions currently available on the older style AAs, and how the functions are moved, picking up where I leave off here.

Basic human functions available to the original AA figures in the shows at Magic Kingdom include:

Lower body: Body foreward and back, body turn, body sidesway, and in special cases like Lincoln and Washington…knee bend.

Mid body: Torso Twist, torso forebend, pelvis.

Arms: Arm forward, elbow. arm swing, wrist turn, wrist forward and back, arm out.

Head: Mouth, head nod, head tilt, head turn, eye blink, eyes up/down, eyes right/left, and in some cases F sound (mouth), smile (mouth).

There are exceptions to every rule. CBJ has all kinds of exceptions because they are large animals, the Father figures at COP are the only ones that had the F sound and smile, and hOP has the new A100 figures which are totally different.

Our mansion figures are fairly simple and do not have but a percentage of the above, mostly arms, torso, mouth and head movements.

All these functions are located in the body where they can perform the most lifelike movement. Remember, an actuator, be it hydraulic or pneumatic has a simple principal, it is a cylinder with a piston inside and a shaft that is part of the piston and extends out of the actuator. At the end of the shaft is usually a connecting bit of hardware, usually a rod end bearing.

Air or oil is under pressure at the actuator. It is delivered there by two tubes, one going to each end of the actuator. The direction of the air is shuttled from either behind the piston or in front of it by directional changes within the valve located in the base frame. This change is coming from an electrical voltage which is provided by the program in DACS, and is provided to the valve for that function. Still with me?
So as the valve changes the pressure from one end of the actuator cylinder to the other, it forces the actuator shaft to extend or retract. Whatever that shaft is attached to will move accordingly.

Going back to the stick figure concept, the skeleton of the AA human figure is tubing. The main structure or body, is aluminum tubing which starts under the base frame as two leg tubes, then these two connect to a hip joint assembly….more bearings and clevises connected to actuators. The aforementioned arms are attached to the main body frame at the shoulders, and the head is attached to the main upper frame in the middle. (makes you wanna break out into the Headbone’s connected to the tailbone song..beat ya to it GD).

Actuators are located as earlier stated, closest to the function that is moving. In the Manse, all the head actuators are located behind the shoulders or in the neck area. In hydraulic shows, the actuators are much smaller, more powerful and fit in the head itself.

I could go on and on about this but it gives you an idea how these things are put together. Not all figures have the same functions..some have only a few, some have many, but none of our Mansion figures have it all. That’s where the hydraulics come in. Been there,done that.


The following TECH POST was contributed by Ray, my audio Tech partner at the WDW Haunted Mansion. The Doombuggy audio system…………..

How It Works

The audio for the Doombuggies, known to some as pods, is an FM narrow band system. It works on four frequencies between 800 kHz and 1.2 MHz, and is a very low power system. There are four transmitters in each of ten audio zones. Also in each zone there is a sensor with an IR (infra red) source and an IR sensitive pickup, or sensor. When a signal is received from the sensor, the specified transmitter turns on,
Along a given length of the track there is a long antenna and on every other pod there is a receiver with a tuned antenna sticking down about 6″. The antenna has to go between the long antennas to receive a signal.


The equipment under the ride and associated with the transmitters, is a power supply and two transmitter cards with two transmitters on each card. Let’s call them ‘channels’. Channel 3 and 4 are on one card, and 2 and 5 are on the other. Later you will understand why there isn’t a channel 1. Then we have a counter card, and that we will clear up later. All these items are inside a box about 24″ X 18″ X 8″. These are just approximate sizes. The box is mounted on a pole next to the track, but under the floor.

The sensor described above is mounted right in the track, inline, and very close to the pods. The sensor works like the old chopper system, used in the early pointless distributors on a car. This requires a chopper to be mounted on the pod, and we will get to the pod later. The chopper has 3 to 6 fingers, about 4″ long and 1″ wide. Three fingers will give you a count of two, and six fingers will give you a count of five. There is no number one, this is to avoid a false trigger from junk being tossed past the sensor. These fingers have to pass within a short time or it will not count.
To operate the system, the pods move down the track at a given speed and the chopper passes thru the IR sensor and turns on one of the transmitters, depending on the number of fingers. Therefore, the ride can be stopped and started and it doesn’t lose its timing, But if you are stopped in a zone your audio drops out, but the transmitter continues to the end of its spiel. You don’t hear it because the pod slows or stops and the power to the receivers drops off. When your pod starts, there is no trigger to start the spiel for the zone you are in so your audio starts again in the next zone. We will cover the pod equipment later.

The counter card receives the chopper pulses, then it sends a signal to DACS and tells the equipment over there what spiel to run, and that transmitter starts sending an audio signal.

The antenna is two wires inside of PVC pipe, and its length is dependent on how long the spiel is for that zone. Short spiel, short antenna, long antenna, longer spiel. The pipes are parallel and about 5″ apart, and run between some track rails. The pod antenna must be between the two antenna pipes to get a signal. If you carried a good scanner such as a R1 from Icom, you still would not hear the spiel unless you put the antenna between the antennas, so carrying one on the ride would do you no good at all.
That should cover the track side equipment.

The pod:

We have 160 pods at WDW, and each pod has three speakers for audio. That is the part you see and hear, but now the rest of the story. There are 20 pods in a string, and the first pod in each string is called an alternator pod. They start with number 1, 21, 41, on. to 141. In each group of 20 there are 10 pods with receivers, so two pods are supplied audio by one receiver. The ride audio is set to a ride length of 8 min 8 sec., I know it runs longer most of the time, but that is what should be ideal. Results of poor timing are: If the ride runs too fast, you will pass thru a zone before the spiel is over, and it cuts off. If the ride runs too slow as it does now (8min 22sec), the spiel will be over too soon, and you might hear part of another spiel, triggered by another pod.

If you hear the end of a spiel as you enter a new zone, it could be that the wrong receiver is in the pod you are in and because the operating frequencies are so close, it picks up one of the others. I know, very confusing. The ride has been running slow for four years now and if it were to run much slower it would start to lose audio throughout the ride because of the alternator pods.

The pod with the receiver has a chopper with it, mounted under, and to the right side DOT( direction of travel) of the pod. The receiver box is about 4′ X 4″ X 8″, and the receiver card is inside. It is about 2″ X 5″ X 3/4″, and is very rugged. I have heard of the speakers being short circuited, and when the short was removed, the receiver just continued to work. The receiver box is powered by 12 volts supplied by the alternator pod. Most of the receivers will continue to work down to 8 volts but after that they shut down. That is why the audio breaks up or stops altogether when the ride slows or stops for a physically challenged person.

I see a lot of people mention that they hear a noise or buzz as they go thru the graveyard. Well, since we are dealing with a receiver that has AGC( automatic gain control), any time there isn’t a strong signal, it affectively increases the input gain, as if you were to turn up the sensitivity of your home receiver. When that happens and you have a lot of high frequency noise from frequency controlled motors like our new drive motors have, you get an awful noise. It can be fixed, but the powers that be ignore the problem even though the fix could be simple.

The alternator pod has a charging circuit and a power distribution box. The charging circuit charges an onboard motorcycle battery and also supplies 12 volts to the rest of the string, 20 pods to a string.

How it works: The battery supplies field voltage to the alternator thru a centripetal switch, and the switch is needed to stop the battery from discharging when the ride stops. When the ride runs at the proper speed, the battery does its thing and the string works, but if it slows, the alternator cannot maintain the voltage and then the audio drops. It sounds like I am repeating all this, but now we see how it all ties together.

We have meters to monitor the voltage and the current thru the string. No, you can’t see them and so it can give us a heads up on a problem before it becomes a failure.
The power distribution box routes the voltage and smoothes out spikes. There is also a back up in case of a string failure, but sometimes it is used when only one or two pods have a problem, and that can cause more trouble than it cures. When you start to string together a lot of pods, the voltage starts to fall off the further back it has to go, and remember what happens to the receivers when the voltage starts to drop.
The biggest problem is the cables that tie it all together, they are in the middle of a constantly moving pod, and very close to a lot of moving parts that will cut or chop right thru a wire. The next in order are batteries, centripetal switches( not the whole unit, but just the switch), and speakers.

The audio comes from DACS, and is stored on ROMS. It is a reliable system and takes a lot of abuse. It has been in use in its present form since the early 80’s, I think. From what I hear, the receivers were redesigned a while back but I have not heard of a date.

There are always rumors of changing the system out, but the cost to maintain what is here is very little compared too the cost of changing everything. It requires a minimal amount of parts and only one or two people to keep it working at our end.

That about covers the ride audio. ;,

(8/18/02 9:11:58 am)
Reply A Little Tech Stuff #?

Greetings once again Techies…..another Animatronics tech post, this time dealing with what makes a Haunted Mansion Animatron work? I have done a couple Techposts on Animatronics, but not one dealing with the ‘Ghosts’ that we all have grown to love.
Audioanimatronics figures as they are officially called fall into many categories. There are the A100 figures such as Lincoln and G.W. Bush in the Hall of Presidents. They are the most advanced figures the parks utilize. We are talking about human figures now, not dinosaurs or other non human creatures. Then there are the A1/A2 figures which are the Large/small human figures of the first generation. These are the predominant figures in the Magic Kingdom. This is the original technology, which 25 years ago was state of the art. Now the A100 figures are that.

The driving force behind these different types deals with computerized programming which is fed to the animatrons via different systems. In the Haunted Mansion, the program is fed from Engineering Central (DACS) to the distribution point wherein the information for each figure is distributed through electronic means. The point of distribution is called the Remote Terminal Unit (RTU). All information which must drive each figure function is distributed from this source through Analog and Digital servocards (circuit boards) which are addressed to each function. Each function, much like your home, has it’s own programming address which then know exactly which route (by wire) to take to move the function.

For all intents and purposes, a function is a movement a figure makes. It might be an elbow, an arm forward, a body sidesway, a head turn or nod and the all important mouth function.

What makes these functions move?

A mechanical device called an actuator. Actuators can be driven by either hydraulic or pneumatic force. Most shows have both. The Mansion is totally Pneumatic or compressed air powered by the 120psi of air supplied to us by Reedy Creek Utilities.

In Pirates for instance, both are utilized. Hydraulic fluid at 500psi is supplied to actuators where a heavy load must be driven such a the Auctioneers pelvis movement, or to a function that needs smooth control such a an arm swing. Hydraulic fluid is not compressible so all movements driven by hydraulics is inherently smoother.

Pneumatics on the other hand are less smooth and controllable because air compresses and the heavier the function to move, the harder to fine tune the flow of motion. That is why so much of the movement in the ghost figures is a little jerky or uneven.
Pneumatic actuators are all linear (straight line) cylinders with an air supply and electronic feedback to provide information and movement. The actuator cylinder contains a piston and seals wherever air could escape. This keeps the 40-80 psi of air that they are set up with inside the cylinder. These actuators come in all different sizes and lengths to provide the exact amount of motion necessary for a particular function. Therefore a mouth actuator is only a couple inches in length as opposed to a body turn actuator which may have total length of 6 or more inches. The amount of movent the piston makes is called the ‘stroke’. The amount of stroke an actuator has is governed by its length of the actual cylinder in which the piston travels, and the size of the piston itself.

Each actuator is connected to the function it provides movement to by ‘linkages’ such as rod end bearings and universal joints etc.

When information is electronically provided to the actuator, it moves from one end of its travel to the other, the amount of movement determined by the computer program. The linkages are the means of transferring the energy to the function being moved…..thus the reason they are called LINKages.

So in conclusion, when you watch a ghost move, you are seeing many actuators being driven separately at the same time within the same ghostly entity. Multiply that times the number of figures, i.e. ghosts, dogs, cats and more, it creates an attraction. This in no way covers the whole subject but I sorta condensed it down to keep you all from falling asleep halfway through.

(8/22/02 6:06:29 am)
Reply Re: Re: A Little Tech Stuff #?

I can’t get over the outstanding questions this particular post generated. At WDW we have a large manufacturing facility called Central Shops. It consists of a fully equipped Mill shop (where all the fancy woodwork is created), an Electric Shop, a Staff shop (all fiberglass work done there), a Sheet Metal shop, a Hydraulics and animation repair shop and a very large, very modern machine shop.

I was hired in as a machinist in Central shops in 1978. The shop was half the size it is now. I worked in it for three years. I was the first machinist to be sent to school and trained to program and operate a Bridgeport CNC mill.

There is a small machine shop in the tunnel near DACS, I transferred to that shop in ’82 and worked there for a year. That is where I worked when I was taught actuator repair. If the chips you are talking about are the metal, sharp edged curly kind, you bet I filled a few barrels of them. I also have a small toolmakers lathe in my shop in the Mansion. Great for making small animation parts.

Everything in the Mansion is old, but amazingly the one key thing I have the least trouble with is the Caretaker figure. He’s my friend

The doombuggies ride on a tubular steel track, much like the Trains at Big thunder ride on. Under the cars is a series of wheels and gear racks which as the vehicle passes over certain mechanisms, rotates the vehicles in certain areas.

The only motors involved are the drive motors along the track that move the 160 vehicles along.

(8/22/02 6:18:34 am)
Reply Re: Projector technical questions

As I stated in my post, the 10X10 referred to is the size in inches of the Fresnel diffusing lens. It is about .125″ thick and slightly convex. The artwork disc is about 2 feet in diameter and is attached to a Lexan disc of the same size. The artwork disc is about .020″ thick. The disc is solid black with the ghosts, Clouds, mist or whatever being transparent on the disc. Don’t ask me how they did it, it just is. Not my line or work. the space between the images is not much, so the black solid space between the images is what separates them. A motor drives the disc at the proper rpm so that you get the continuous motion that you see. The mists and clouds rotate at a much slower speed or it would look like a hurricane going on outside those windows.
Not having ever been to DL It sounds like the rising ghosts have just had their outline etched on the black artwork. At WDW, the whole ghost has been etched out, which is why they appear as solid white.

Whereas the projectors projecting the flying ghosts face directly at the scrim they are projected on, the coud and mist projectors project in a parallel manner along the length of the scrim. This is why they look flat. Ingenious engineering if you ask meAs you enter the Graveyard downramp, you notice many ghosts flying together…that is because there are two projectors side by side projecting the images…and yes they are the same effects as at DL.

Personally I find them also a pain to keep up and they eat up 2000Watt lightbulbs.

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1 Comment

  1. Barb

    August 4, 2014 at 12:36 pm

    Wow! It’s mind boggling how much maintenance goes into just the upkeep on the animatronics!

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