Actuators help giant NFL player to move realistically
A 7.9m-tall replica of an American National Football League player was unveiled recently in London’s Trafalgar Square to mark the first regular NFL game to be played outside the US - a contest between the Miami Dolphins and New York Giants which took place at Wembley Stadium on 28 October.
The giant figure of the Miami Dolphins’ star Jason Taylor - thought to be the world’s largest ever animatronic human - relied on more than a dozen electric actuators it to move its huge head, arms, legs and feet in a life-like manner.
The London-based special effects company Artem was given just ten weeks to design and build the figure. A team of more than 40 specialists worked around the clock to ensure this feat of engineering was ready for its Trafalgar Square debut, where it came face-to-face with its namesake for the first time.
The lifelike giant was first sculpted as a 0.8m-tall clay model which was scanned, along with a real NFL helmet, boots and gloves, to provide data that was used to cut the body parts out of polystyrene. Simultaneously, the internal mechanism and supporting structure were designed using Autocad and Solidworks.
The finished figure weighs more than a tonne, has movable feet and arms, 2m-long boots with custom-made 6.5m laces, a handspan wider than a doorway, and movable eyeballs the size of grapefruits. His bespoke football kit was made from nearly 150m2 of official NFL fabric. He is supported, powered and propelled by a five-tonne mobile crane.
The moving limbs posed a problem for the designers. Originally hydraulics were considered, but the ancillary equipment that this would have required created concerns. Electric actuators offered a much simpler alternative, and Artem approached Simon Gillingham of Rotherham-based Acorn Industrial Services’ linear division. He was asked to specify actuators that would be powerful enough to move the giant’s massive limbs, and to mimic human movements in terms of speed and smoothness. Gillingham suggested using SKF linear actuators to provide the required performance and dimensions.
A key factor in supplying the actuators was the short lead time – they were needed within two weeks of ordering. By working closely with SKF in the UK and Sweden, Gillingham tracked them every step of the way to make sure that the delivery was on time and that the specification was correct.
Jamie Campbell, who was one of Artem’s supervisors on the project, comments: "Big JT is truly awesome to stand next to – especially in the knowledge that he moves!
After meeting the actor Christian Slater and London mayor, Ken Livingstone, the massive player made a tour of London before making his way to Wembley Stadium for the big match.
