Veltins Arena is the home of the FC Schalke football team, but is also used for many other types of event including motorcycle speedway racing and pop concerts. For these events, the playing surface is completely retracted, protecting it from damage and freeing up the whole of the central area of the arena for non-football use.
To make retraction possible, the turf of the playing surface is bedded in a giant tray 118m long by 79m wide, which is supported on 16 steel rails embedded in the arena’s secondary floor. When the pitch is not being used, the tray, which weighs 11,000 tonnes, can be moved 170m in either direction, leaving the arena’s central area clear. A further benefit is that the sensitive turf is moved to a location where its growing conditions can be readily optimised.
The tray containing the pitch is moved by four hydraulic jacks that push it forward at a rate of 1.5m/min. At intervals, electric motors demount the jacks, move them further along the steel rails in the secondary floor and remount them again. This cycle is repeated until the tray has moved the full distance required – a process that takes between three-and-a-half and four hours.
A key requirement for the success of this project was to devise a dependable way of supplying power to the motors, which would not only cater for the regular movement of the pitch, but would also operate reliably in all weather conditions. The solution, developed and implemented by igus, was the use of energy chain cable carriers in conjunction with Chainflex cables.
For this demanding application, Rol-E-Chain, which was originally developed to protect cables in long-distance, high-speed applications, was selected rather than the standard igus E-Chain. This was because of the need for the installation to cope with adverse weather, and to handle large loads moving over long travel distances. Rol-E-Chain features integrated rollers, which reduce the power needed to drive it by up to 75 percent. Wear is therefore also reduced, and the use of rollers prevents the upper run from freezing on to the lower run in cold weather.
Special igus Chainflex cables were used inside the Rol-E-Chain carriers. These cables were chosen as they are optimised for use with energy chains, and because they have been rigorously tested under the most demanding conditions at the igus technical facility. The cables are suitable for indoor and outdoor applications – they remain flexible down to -35°C and can be used at temperatures up to +100°C.
The retractable pitch at the Veltins Arena has now been in use for several seasons, and the cable system has proved to be completely reliable, despite being called upon to operate in weather conditions of all kinds, over a wide range of ambient temperatures.
igus was the first company to develop complete energy supply systems comprising cables and energy chains from a single source with a system guarantee. igus energy supply systems are finding widespread applications not only in industry but also in many other application areas, including theatres, television and film studios, passenger lifts, mechanical handling equipment and, as the application at Veltins Arena has shown, in the sports and architectural sectors.
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