Hydraulics enables dinosaurs to move and walk in a live stage production.
No one has ever seen live dinosaurs, or course, and when we see lifelike looking dinosaurs, they're usually in a movie or on television. You can see animatronic dinosaurs at Disney World and traveling exhibits, but these dinosuars are static — they don't move around much.
Walking with Dinosaurs Live — The Arena Spectacular is a travelling theater production that breaks new ground, with dinosaurs that walk and even run. The animatronic figures in Walking with Dinosaurs Live are electronically controlled puppets that mimic the movements of a puppeteer positioned off-stage or inside the dinosaur. Smaller animatronic figures, like the baby tyrannosaurus rex in this video, have a puppeteer inside who provides mobility and also controls body movements of the figure. Larger figures, such as an adult T-rex, are controlled offstage. This video shows the promotional trailer of the show. Batteries and a hydraulic power unit are hidden in a ground effect that also supports the weight of the larger figures. A person in the video provides a scale reference so you can see how huge these things are.
Here's another fun video that shows a young T-rex being presented as a trained wild animal. You can even see a "trainer" standing alongside the figure to ensure it doesn't get out of control.
According to Sonny Tilders, a designer at Walking with Dinosaurs Live, "We use a system called muscle bags, which gives these creatures their authenticity and makes the audience feel they’re watching flesh and blood weighing six, eight or even 20 tons, come to life in front of their eyes. The muscle bags are made from stretch mesh fabric and filled with polystyrene balls, stretched across moving points on the body. These contract and stretch in the same manner that muscle, fat, and skin does on real creatures.
"The puppeteers use voodoo rigs to make many of the dinosaurs move. They are miniature versions of the dinosaurs with the same joints and range of movement as their life-sized counterparts. The puppeteer manipulates the voodoo rig, and these actions are interpreted by computer and transmitted wirelessly to make the hydraulic cylinders in the actual dinosaur replicate the action. A driver hidden below the animal, helping to manoeuver it around the arena."
These animatronic figures are certainly cool. I'd love to borrow the T-rex as a Halloween costume.