UK based automation experts Kinesys designed and supplied the bespoke motion control system that moves and shapes the 'transforming' video screen for U2's 360° world tour.
The system consists of 40 Kinesys Evo zero-speed chain hoists and 8 custom built winches, all controlled by their K2 3D software control package.
Kinesys' Dave Weatherhead comments, "This was the heaviest, most complex and interconnected system we have undertaken to date, with 48 motors following unique motion profiles to allow the deployment of over 52 tonnes of video screen."
The screen was originally conceived by Willie Williams and Mark Fisher, long term creative collaborators on U2 shows. New York based designers/architects Hoberman Associates assisted Innovative Designs in engineering and realising the revolutionary centrepiece for the show, which consists of 888 individual hexagonal panels which support 500,000 Barco LED pixels. The entire structure can â€˜stretch' from its 7m compressed height to over 22m at full extension forming a conical shape as it expands.
The screen structure hangs in the middle of the giant 4-legged "claw" structure that sits centrally in the stadium with the stage below allowing the audience to surround it and offering superb sightlines from all angles.
It weighs 52 tonnes including the supporting trussing and this is what Kinesys was tasked with moving into its different shapes and sizes. Kinesys worked closely with Nick Evans, who was co-ordinating all the technical aspects of the tour for promoters Live Nation, and Jeremy Lloyd of Stufish to ensure the seamless integration of the automation element into the overall structure.
The 40 Kinesys Evo chain hoists – 16 x 2 tonne and 24 x 1 tonne – are connected to the screen structure at equal intervals and at four different heights. These then move, following pre-defined non-linear paths to ensure that the screen is deployed in a fashion that is both structurally sound as well as visually pleasing. Hoberman supplied Kinesys with the movement profiles in the form of a spreadsheet which was then imported directly into K2 and referenced by each of the 40 chain hoists. Millimetre accurate tracking of the profiles was essential to maintain the structural integrity of the screen, and complex algorithms were employed within K2 to ensure that the real world followed the theoretical at all times.
The hoists associated with the different levels within the screen move at notably different speeds. The uppermost hoists at times travel at less than 1 mm a second, while the ones nearest the bottom of the screen move at over 160 mm a second when the screen is deployed at full speed.
The screen is flown up and down by 8 x 7.5 tonne winches running synchronously. These are capable of speeds of up to half a metre a second - although some of the moves involve travelling just 2m over 5 minutes, resulting in the very slow and smooth movement required.
The winch design resulted in large numbers all round! The winch self-weight is 2.5 tonnes with the gearbox alone weighing over 1 tonne. A single ultra-compacted 28mm diameter steel wire rope provides the connection to the screen with a breaking load of over 75 tonnes, giving a 10:1 safety factor for each rope. Each winch is driven by a 37kW motor powered by a 45kW drive unit.
The same safety technology is employed in both the winches and the hoists. Four limit switches, dual encoders, dual brakes with monitoring and a load cell make up the comprehensive safety package implemented in each device
Additionally, Kinesys is supplying the tour with control for 10 fixed-speed chain hoists controlled by an Elevation 24. These hoists fly 4 lighting trusses bordering the screen into position at the start of the show.
Nick Evans comments, "The K2 system is the ideal tool for controlling the U2 screen, the operator only controls 2 parameters; the degree to which the screen is opened and the overall height of the screen, K2 does everything else. Kinesys has provided the tour with an excellent service, and working with them reminded me of why I enjoy my work so much. Nothing seemed to faze them, even when the requested safe working load increased by a tonne per winch .... it was all considered and taken in their stride. All this, plus they were on time and on budget, who could ask for more?"
Jeremy Lloyd of Stufish adds, “It's again been a pleasure working with the Kinesys team. They always deliver high quality, innovative products that are well packaged for the touring environment. There's only a handful of automation suppliers with the experience and technical expertise to deliver a system as complex as was required for U2 360, and on this occasion Kinesys proposed and delivered the most appropriate package at a competitive price.”