Posted to News on 25th Aug 2009, 13:18
Customised actuators keep Centre Court roof locked in place
Power Jacks has supplied 42 customised electric linear actuators for use as locking devices on the Wimbledon Centre Court retractable roof, 36 of which operate when the roof opens and closes.
In January 2004 The All England Lawn and Tennis Club announced plans to build and construct a fully retractable and weatherproof roof over its famous Centre Court in readiness for the 2009 Wimbledon Championship.
The new roof, five years in the planning and three years in the making, is a retractable 5200m2 folding fabric concertina, manufactured from a new translucent, waterproof material called tenara that transmits natural light when the roof is closed. The design and build of the roof was commissioned by a consortium of companies that included Street Crane Xpress (SCX), whose role in the build was to focus on the mechanisation and control of the roof, enabling it to open and close depending upon weather conditions.
Power Jacks was selected by SCX as a prime technology partner to design, manufacture and supply 42 bespoke electric linear actuators to create locking devices, 36 of which operate when the roof opens and closes. In providing specialised engineered actuators for this challenging application, Power Jacks was integral to the project to improve playing conditions on Centre Court and contribute generally to a more pleasant spectator environment at this historic venue, whatever the weather!
Andy Dowell, European Sales and Business Development Manager at Power Jacks, speaking after the roof was installed, said: "We were extremely pleased to be again chosen by SCX Ltd as their solution provider, and this time for the highly prestigious and highly visible application at Wimbledon Centre Court. The exacting specification called for an acute understanding and close co-operation between SCX's highly talented project team and our Area Sales Manager Frank Shinn. Working successfully to fulfil the performance requirement defined, we were ultimately rewarded with the order that was placed at the end of December 2005 and delivered in March 2006. So now, almost four years on, we are of course delighted to see this installation finally fulfilling its purpose in readiness for the start of this years' summer championships, and all under the gaze of a truly worldwide audience."
Locking and unlocking roof segments
The roof, measuring 80m long, is divided into two sections with a total of nine bays of structural fabric (four bays in one section and five in the other). Each of the nine bays is clamped on either side by prismatic steel trusses. Altogether there are ten trusses spanning 77m across the court. At the end of each truss there is a set of wheels that glide until the two sections overlap, giving the equivalent coverage of 7500 open umbrellas!
For much of the roof's working life it will be parked in the open position. When the roof is ready for closing, one section is parked in its folded state at the north end of the court while the other is parked at the south end. Again, a combination of actuators and arms form the mechanism for closing the roof at a maximum speed of 214mm per second. The mechanism moves the trusses apart and, at the same time, unfolds and stretches out the fabric between the trusses over the court until the two sections meet in an overlapping seam above the middle of the court. At this stage 36 linear actuators from Power Jacks lock the sections of the roof in place. These linear actuators used for locking and unlocking the roof segments were specially designed by Power Jacks for the Wimbledon roof using 3D design technology to optimise the design process and integrate with SCX.
With the roof closed over the court, the arch shape to the tops of the trusses helps the structure to withstand loading from elements such as snow and wind. The shape also assists in providing 16m clearance, which is sufficient for even the highest of lobs.
Reliability
A key element of the design has been to allow natural light to reach the grass, while an airflow system removes condensation from within the bowl to provide the optimum internal environment for the comfort of spectators and players when the structure is closed. The roof has been designed to close in under 10 minutes. If the roof is being closed for rain, court covers will protect the grass in the usual way while closure is in progress. After the roof has been closed, play can resume in approximately 20 minutes, depending on climatic conditions, allowing television companies to be able to broadcast almost unbroken coverage of play on every day.
The benefits of having a moving roof are clear to see. No longer will there be unpredictable and long-lasting rain, which, in the past, stopped play during prestigious games. It will also enhance the Wimbledon Centre Court without compromising on its longstanding design.
The project is now complete and on 17 May 2009 the official inauguration and testing of the roof was held on Centre Court. On the day, under the watchful eyes of four grand slam players and 15,000 spectators, the roof closed in 7 minutes and 4 seconds to a rapturous applause from all who witnessed this historic event. Daniel Salthouse, Project Manager for SCX, said: "Reliability was always the key issue when considering which equipment suppliers to use on the roof. We chose Power Jacks both as a result of the numerous successful projects that we have used their equipment on in the past and because of their ability to meet our demanding specifications".
The Power Jacks Group has been supplying products and aftersales services to SCX for over a decade and has worked with SCX on projects ranging from building maintenance to glass manufacture and mechanical handling.
Follow the link for more information about the Power Jacks Rolaram and special actuators.
