Mark IV monorail

The Mark IV monorail is a design model of straddle-type monorail trains. The design was developed by legendary Disney Imagineer Bob Gurr. Ten trains were built by Martin Marietta in 1969 at the cost of about $7 million USD each and they were used on the Walt Disney World Monorail System between 1971 and 1989 before they were replaced by the Mark VI monorail, although a few lasted until 1991. Sometime between 1991 and 1994 Monorail Coral and Lime (which had been introduced new in 1984) were sold for $3.5 million each, refurbished, and used to begin the Las Vegas Monorail operations. In 2004 Lime and Coral (now the MGM and Bally) were replaced by fully automated Bombardier MVI 4-car trains.

As Walt Disney Productions began to finalize its plans for Disney World in Florida it was decided that monorails would be used as a primary means of transportation for this new “Vacation Kingdom." While the monorail system would not be as extensive as Walt Disney's original plans for the Florida site, it would still be the primary mode for transporting guests throughout the resort. Walt Disney envisioned that the monorail would be the transportation system of the future. To preserve the aesthetics of the resort and to separate the theme park from the outside world the parking facilities for the Magic Kingdom were built nearly a mile across the 200–acre Seven Seas Lagoon creating one of the world’s largest park and ride operations. This would be the first Disney monorail system that had a real transportation purpose. It was no longer a ride in the park but a necessary element to the resorts continued operation. Disney put its nearly 10 years of experience with the Alweg–designed monorails of Disneyland to good use and began the process of creating the monorail system. Inspired by the look of the popular Lear jets Disney Imagineer Bob Gurr designed the new Mark IV trains. The Mark IV trains were manufactured by Martin Marietta in Orlando, Florida with 10 trains originally being built. When two additional trains were needed in the mid-1980s as attendance increased, Disney turned Walt Disney Imagineering to build the additional units.

...
Wikipedia