Walt Disney's biggest dream comes to life October 1

Dumpsters, laden with Florida sand, scurry everywhere. Towering cranes swing steel girders on high and bulldozer blades bite deep into the earth. Graders carve out roads and walkways where none existed before, and an almost unending stream of trucks pour concrete into shapes and forms that were only dreamed of a few months ago.

There is no time to waste anywhere on this 260-acre construction site currently rising up among the pines and oaks of central Florida; that much is obvious. A sense both of purpose and of urgency prevails here on the outskirts of Orlando, as Walt Disney's greatest dream, his presentation of tomorrow, takes tangible shape.

They call it EPCOT -- the Experimental Prototype Community of Tomorrow -- one chunk of Walt Disney World's 550 acres and a short monorail hop from the Magic Kingdom. In construction project terms, the deadline for its completion is just around the corner. As the sign at the entrance to the exhibit previewing EPCOT makes clear: ''The 21st century will begin October 1.''

No one doubts here that the vast entertainment-education spectacular will open on time. The Disney organization has a longstanding reputation for achieving the impossible and of meeting deadlines. ''Even if every employee is out laying down turf the night before,'' says one who remembers the Magic Kingdom's opening 10 years ago.

EPCOT Center will cover twice the acreage of the Magic Kingdom. At $800 million it will also cost twice as much. But, it will incorporate new entertainment techniques as advanced from Disneyland as that original theme park in California was from the old-fashioned amusement parks of the '50s. As Walt Disney wanted it, EPCOT will be ''a community of creative concepts, a showplace where the achievements and potentials of science, industry, and the imagination can be made entertaining and stimulating for millions of visitors.''

Simply put, Disney went to industry and science and said in effect: ''You have the knowledge and we have the imagination. Let us combine our talents so we can show the world what the 21st century will be like.''

In fact EPCOT does much more than that: It displays the past, present, and future technologies in the theme area, ''Future World.'' In ''World Showcase,'' the second theme area, it has put the world on display for the tourist.

As it did with industry, the Disney organization contracted with overseas governments to exhibit the best of their cultures and their traditional products here at EPCOT. The idea, says Charles Ridgeway, Walt Disney World publicity manager, ''is to make touring the rest of the world as simple as visiting Florida.'' In the hands of Disney ''imagineers,'' the realism will be impressive.

As an idea, EPCOT predated even the decade-old Magic Kingdom, currently the world's No. 1 individual tourist attraction. But even Disney felt that it was too bold, too advanced a concept to introduce to the public before the Magic Kingdom had established this central Florida area as a tourist attraction. Now, with the addition of EPCOT, projections suggest that Disney World's current 13.5 million annual attendance figures will rise to 20 million.

There were those who predicted EPCOT would never fly. But the critics have said the same about almost everything Walt Disney ever did. When Disney first hit Hollywood in the 1920s, offering his talents as an animator, no one considered him worthy of a job. So he started his own studio, turning out early animated cartoons. They caught on but the existence of the new studio was tenuous at best. Then along came a character named Mickey Mouse. Donald Duck followed, and the Disney organization was off and running. It never looked back.

In the late '30s, Disney's introduction of a full-length animated feature was branded as crazy. No one would go to see a full-length animated cartoon. But ''Snow White and the Seven Dwarfs'' was a box-office hit.

If the financial advisers had been heeded, Disneyland and Disney World's Magic Kingdom would never have been built. They simply did not make economic sense, yet in each case attendance figures quickly exceeded even the imagination of Disney.

In the Disney experience, imagination has repeatedly triumphed where pragmatism deemed the mission impossible. Such was the case with Disney World's WEDway people-mover (WED Enterprises being the ''imagineering'' arm of the organization) and the linear-induction motor.

Linear induction is an old, established principle. But apart from moving drapes in some theatres, and letters in some post offices, it had never been put to practical use. Disney engineers thought it should move people, too.

With an aerospace company in partnership, they set out to solve the problems. But progress was slow. Finally the aerospace engineers pulled out, saying they doubted linear induction would ever succeed on the scale Disney sought. Only an organization used to dealing in dreams on a daily basis could have carried on under the circumstances.

The close tolerances between the people-mover and the rail were critical, and when computers finally resolved this, the people-mover was a success. It has carried visitors through the Magic Kingdom's ''Tomorrowland'' for six years now with a minimum of down time.

On the strength of this, Houston contracted with Disney for a similar system linking the terminals at its new airport. It has successfully operated there for the past year now. More inquiries are coming in for the Disney people-movers -- all because Disney dreamers couldn't see the impracticality of it.

More recently, Disney's own accountants cautioned against building Walt Disney Village on its Florida property. But the company went ahead anyway and in just two years the visitor level reached the mark projected for 10 years ahead.

EPCOT, then, seems destined to succeed in a big way. Disney saw it as the biggest and the best of all his ideas; his crowning achievement. He also saw it as a continuing project, something that would never stop growing. His present-day imagineers see it that way too.

Already EPCOT more than hints at the excitement it soon will generate. Dominating the scene is Spaceship Earth, the world's first complete geosphere, a mammoth globe standing 18 stories high that serves as the entrance to the Future World at EPCOT Center. It also houses the communications exhibit, sponsored by the Bell System, in which a spiral ride will take visitors to the roof of the geosphere on a journey displaying communication systems from the crude beginnings to concepts for the coming century.

Other journeys through Tomorrowland will allow visitors to explore the worlds of energy, motion, imagination, invention, and the systems that sustain life on the land.

In the land exhibit, sponsored by Dart & Kraft Inc., boats will carry visitors (up to 2,000 an hour) through three agricultural exhibits in which growing plants become the stars of the show. Many will grow vertically, some on floating platforms, still others will be fed by a fine nutrient spray as they pass through the plant equivalent of a car wash. Another demonstration will show how fresh food will be grown in giant space satellites of the future.

Some half million plants have been identified as suitable food sources for man, though currently he uses a mere 150. Among the food-crop superstars are some near-unknowns, which may well become commonplace on supermarket shelves of the future.

In World Showcase, the cultures of eight nations - Britain, Canada, China, France, Germany, Italy, Japan, and Mexico - along with the US, will be presented during the opening phase. Other nations will be invited to join in the years ahead. The architecture is the romantic design traditionally associated with each nation. ''If we were to present the modern side of each nation the differences would be difficult to detect,'' says Ridgeway.

So, we have Victorian shops in Britain, the Eiffel Tower (one-tenth the true size) in France, a Shinto shrine in Japan, the Campanile tower in Italy, the pagodas of mainland China, and Aztec pyramids in Mexico, among others.

In Canada you will visit a chateau in a north woods setting in which the woods around you are realistically displayed on a 360-degree screen. Even the scents are there to heighten the realism. And, that's yet another of a hundred interesting stories surrounding the development of EPCOT.

Bob McCarthey, working with fellow engineers at WED Enterprises in California , developed a ''smellitizer machine'' to add the aroma of everything from erupting lava in the ''Universe of Energy'' show to the fragrance of orange blossoms. While many of the aromas will be subtle, the appetizing smell of the barbecue in the US pavilion will be obvious enough to send you away salivating. There will be a mild animal smell as you pass through a farm scene and the smell of rich damp earth in a garden setting.

The late Mike Todd introduced what he termed ''smell-a-vision'' to the world in the 1950s, according to McCarthey. The trouble was the aroma didn't get to all corners of the theater at once and often the smell lingered long after the appropriate scene had changed.

Since at EPCOT the audience moves to the scene, rather than the other way round, the matter is simplified considerably. In addition, the ''smellitizer'' works like a cannon. It shoots the aroma to the appropriate spot with remarkable accuracy. Computers time the release, of course.

In all, EPCOT seems destined to be another triumph for the imagineers in what might be termed the art of ''illusioneering.''