Retractable Pitches Around the World
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THE FOOTBALL PITCH IN THREE PIECES WEALTH CREATION Tottenham Hotspur Stadium is part of a regeneration project that has transformed the stadium and surrounding area. As well as being home to Tottenham Hotspur Football Club, the stadium will host NFL games in the UK, and to accommodate both sports, the stadium boasts the world’s first dividing sliding pitch. Science journalist Richard Gray asked Danny Pickard, lead engineer at SCX, RETRACTABLE PITCHES AROUND how the pitch was developed. THE WORLD While the Tottenham Hotspur Stadium now has the first retractable pitch that divides into sections before it is rolled away, it is not the first stadium in the world to have a removable grass field. In 1998, the first major sports stadium to get a so-called ‘convertible pitch’ was the GelreDome in Arnhem, Netherlands. Home to the football club Vitesse Arnhem, a huge concrete tray that contains the turf can be pushed out through an 85-metre For 118 years, White Hart Lane, will be played on the world’s opening under the south stand to make way for concerts and home of Tottenham Hotspur first dividing, retractable other sporting events. It takes around three and a half hours to Football Club, has been one of grass football pitch. Mounted move the enormous slab and it is usually left outside the stadium the most famous addresses in in three enormous trays, the in the wind, rain and sunshine so that the grass can grow. football history. The stadium grass surface can be rolled In 2001, retractable pitches were installed at both the Arena hosted some of the team’s away beneath the south AufSchalke football stadium, which is now known as the Veltins- most dramatic moments, from stand to reveal an artificial Arena, in Gelsenkirchen, Germany, and at the Sapporo Dome in famously picking apart the NFL American football Toyohira-ku, Japan. The 11,000-tonne playing field at the Veltins- formidable Polish side Górnik field beneath. The Premier The football pitch at the new Tottenham Hotspur Stadium hides an artificial NFL field underneath. The pitch slides over in three metal trays, each weighing over Arena, home of the Bundesliga side FC Schalke 04, can take six 3,000 tonnes, which are stored beneath the stands when not in use © Tottenham Hotspur / SCX Special Projects Zabrze in its first ever European League Club already has a to eight hours to move in or out of the stadium. Four hydraulic Cup appearance in 1961 to 10-year contract with the presses push the lawn about half a metre at a time in what can defeating Inter Milan during its NFL to stage a minimum of be a 340-metre round trip. first Champions League outing two games a season, using The Sapporo Dome primarily hosts baseball and football in 2010. In total, Spurs played the artificial surface. The games for the Hokkaido Nippon-ham Fighters and Consadole 2,533 competitive games at retracting pitch means that Sapporo FC. The pitch here is the world’s first ‘hovering football the North London stadium the stadium can quickly stage’, where the 8,300-tonne field partly floats on a cushion before demolition work began convert from hosting a of air as it moves, reducing the weight that the 34 wheels in May 2017 to make room for football match on the grass underneath have to carry. To convert the stadium, the artificial THE FOOTBALL a new 62,062 seat stadium. This pitch to an NFL game on baseball field rolls away and a bank of seats are retracted into the redevelopment, rumoured to the artificial field in just walls. The pitch rolls into the arena and rotates 90 degrees along cost around £850 million, has a few hours. The hard- with a revolving bank of seats until moved into place, and the not only almost doubled White wearing artificial surface also retractable seats move back into place. In total, the whole process Hart Lane’s previous capacity, means that the stadium can can take four or five hours. but has also turned it into one of host other events, such as Most recently the 63,400-seat University of Phoenix Stadium PITCH IN the most flexible major venues concerts, without damaging in Glendale, just west of Phoenix, Arizona, opened in 2006. It in the world. At the very heart the grass. For most football makes use of the space outside the stadium, rolling the 9,300- of the stadium, the pitch has grounds hosting concerts tonne grass playing surface out through an opening at one been transformed from a simple and other events involves end in around one hour. This has allowed the stadium to host patch of grass into an ambitious putting thick matting onto events as diverse as motorsports, wrestling matches, NFL games, engineering project. the pitch, which can quickly international football matches and concerts by acts including Matches at the new kill the grass and requires Beyoncé, Taylor Swift and U2. THREE PIECES Tottenham Hotspur Stadium new turf to be laid before the 14 INGENIA INGENIA ISSUE 77 DECEMBER 2018 15 THE FOOTBALL PITCH IN THREE PIECES WEALTH CREATION The whole pitch weighs over 9,000 tonnes, more than the Eiffel Tower in Paris. Each of the three sections need to fit together seamlessly so that fans watching football games, and footballers taking part, cannot tell that matches are happening on trays mounted 1.6 metres above solid ground grow. The team initially used a observes the pitch’s progress. Once it has stopped, a parking the inside edge of this structure device similar to a pizza cutter to Moving the pitch sections brake – similar to the one in a can be lifted or lowered using slice between the sections, but requires both operators to car – is applied to clamp the hydraulic actuators. it left noticeable damage when continually press down their structure in place. The outer Once the pitch is in place, the pitch was reassembled later. safety buttons. An automatic sections then move inwards to hydraulic cylinders raise the Instead, it found that the best slow-down system is triggered meet the centre of the pitch sidelines before the flaps are approach was to simply let the as the huge pitch sections trip with the help of 32 hydraulic lowered to rest on the edge turf tear naturally as the sections sensors when the sections cylinders on the steel structure of the turf. Ramps in each pulled apart, allowing it to split are 75 centimetres apart. This underneath. corner of the pitch also pivot along its own weak points. slows the movement down There needs to be enough upwards with the touchlines To ensure that each section to the tenth of its top speed space to allow this to take to give access from beneath would line up, the first tray – just seven centimetres per place, so the team created the stands. Then the entire module in each was surveyed minute – before triggering a touchlines that move too. structure is locked into place. At into place to make sure it second and third sensor that Along the length of the pitch, the north end of the stadium, a was correctly aligned, before brings the whole structure to touchlines are mounted on top third set of flaps hides a series Extensive testing of the sliding pitch prototype was undertaken at Tottenham Hotspur’s training centre in Enfield © Tottenham Hotspur / SCX Special Projects the other trays were bolted a halt. The motors themselves of a huge steel structure with of growlights and sprinklers alongside. When complete, can be used to slow and brake artificial turf bonded to the that can be wheeled out over next match can be played. This single entity, as has been done and cooling, caused by the the trays were lined with a the pitch while it is moving. surface. Six-metre-wide flaps on the pitch between games can take days, if not weeks, for with other retractable pitches JOINING THE PITCH welding, making the steel waterproof layer before matting, most stadiums. around the world [see box on The whole pitch weighs over buckle and bow in different gravel and soil were put on top. The football club turned to the previous page]. Instead, SCX 9,000 tonnes, more than the ways. The team built a test Then the turf itself was rolled out Sheffield-based engineering opted to split the pitch into three Eiffel Tower in Paris. Each of site at Tottenham Hotspur’s over the top. firm SCX to help deliver the lengthwise sections that divide the three sections need to fit training centre with a section retractable pitch. SCX specialises roughly along the outer edges of together seamlessly so that of movable turf to experiment in complex kinetic architecture the penalty box. fans watching football games, how the pitch would fit ON THE MOVE having previously created the Once this concept had and footballers taking part, together. With a length of Sixty-eight electric motors enormous retractable roof over been agreed, the club tasked cannot tell that matches are 21 metres and a width of 3 power every second tray in each Centre Court and No.1 Court its Head of Moving Structures happening on trays mounted metres, this gave the team a section, with the ones on the at Wimbledon. It also built a Nick Cooper FREng and his 1.6 metres above solid ground. more manageable replica of centre rail doing most of the 900-tonne section of removable team with designing and fully Ensuring the accuracy required the edges to experiment with.