THEY walk and run, tilt their heads and turn, roar and blink with such realism that within the first few minutes of seeing the dinosaurs in action you're trying to work out just how they do it.

The only clue is the oblong base underneath each one, painted a beige colour to match the arena floor...

And only on a backstage tour after the show at the Izod Centre, a short drive from the centre of New York, does it becomes clear how these life-size dinosaurs operate.

The base is where the driver sits, moving the dinosaurs around the arena on a carefully rehearsed route. map.

"They're basically like a go-kart," says resident director Cameron Wenn. "The driver is in liaison on headsets with two animatronic voodoo operators."

Voodoo? More of that later.

Behind the driver's back is a steel mast which holds together the steel and aluminum skeleton over which is a foam structure that is sculpted to make the body shape.

"The skin is spandex-treated with latex stencilling and then hand-painted.

"There's about a mile and a half of skin in the dinosaurs – and all of it was made by hand, stencilled by hand and painted by hand.

"And they have a series of muscle bags, like a stocking material filled with polystyrene balls, that gives the effect of muscle movement."

OK, so we know what they're made of ... but how do they stretch and turn and blink and roar?

Back to the 'voodoo' puppeteers who work from the back of the arena, out of sight.

"The puppeteers use voodoo rigs," says dinosaur designer Sonny Tilders, who worked on the movies Star Wars: Episode III – Revenge of the Sith, Peter Pan, Ghost Rider and The Chronicles of Narnia.

The term comes from the similarity of the rigs – mini versions of the dinosaurs – to the voodoo doll, except instead of pins and magic they're using pads and radio waves.

"The rigs [have] the same joints and range of movement as their life-size counterparts. These actions are transmitted by radio waves to make the hydraulic cylinders in the actual dinosaur replicate the action."

A second puppeteer is in charge of the sounds each dinosaur makes and the intricacies of eye movements and facial expressions. Each dinosaur is capable of 30 actions.

"The technology has only been seen before in film," says Voodoo captain Graeme Haddon.

"And this is the first time that puppets this big have been operated by remote control."

Three teams of three are at work bringing the dinosaurs to life during any single show.

"After a while the three brains think as one," he adds.

The space where each driver has to sit looks tight, claustrophobic even: imagine a canoe converted in to a go-kart.

"They're actually pretty comfortable," says head driver Michael Hamilton.

"I have been known to fall asleep in there. Not during a show though," he quickly adds.

"It can get pretty heated in there once the motor gets going."

"It's like driving a lorry. You have to think a lot more about turning.

"The tails you can't actually see and T Rex almost takes out the audience in a few venues that we go to."

Do they have races? Hamilton laughs.

"We did initially back in Sydney during rehearsals. We got them up to about 10kph.

"We're all desperate to take them down the main street of New York but no-one will let us out."

Hamilton trained as an actor but fell into puppeteering, which led to his current job.

"If someone had asked me two years ago what I'd be doing now, it probably wouldn't have been 'Driving a dinosaur around the United States'.

"It's funniest when you go through customs and you fill out your occupation as Dinosaur Driver."

Of the 15 dinosaurs in the show, ten are operated by a three-man team. The flying Ornithocheirus is purely animatronic while the three Utahraptors and the Baby T Rex are men in 100lb suits.

Though it's a little more complicated than, say, Mr Blobby.

Justin Terry is the suit captain, in charge of a team of six and the Baby T-Rex in the show.

It's an odd career choice isn't it?

"My mates who I studied acting with are all off doing great theatre, like Othello and the like.... and I'm a Baby T Rex. But I've played to over a million people and not many people can say that."

simon.wilson@nottinghameveningpost.co.uk