A reliable energy supply system for the moving pitch at the VELTINS Arena

"The world has never seen a stadium like this," enthused FIFA President Joseph Blatter about the VELTINS Arena. The European football association UEFA rated the multifunctional venue in its highest awarded category as a 'five-star stadium': "The venue more than fulfils the requirements and could even be rated as a 'six-star stadium'." One of its hallmarks is the mobile pitch. It is moved over a simple distance of 170 meters with the help of two space-saving roller e-chains® and special cables from igus®.

From Bruce Springsteen to the government summit

These hymns of praise emphasize the response that the arena has received since its opening in August 2001. Within a very short amount of time, it has established itself as one of the most modern venues in Europe. UEFA ranks the stadium in the highest classification, Category 4. To date, millions of people have attended more than just sporting events. From stock car races to music concerts and biathlons, the stadium has hosted a wide range of events.

The stadium, which was financed entirely by the private sector, impresses with its technology. The retractable pitch, the closable roof, the movable south stands, and the oversized video cube under the roof are just some of the technical highlights. With the "Knappenkarte", a cashless means of payment based on chip technology was established. The admission ticket is also based on chip technology and controls access easily and securely.

Giant trough as a drawer: the retractable pitch

The playing field of the VELTINS Arena is more than just a green pitch. Embedded in a 118 meter long and 79-meter-wide trough, it is the only pitch in the Bundesliga that moves back and forth over a distance of around 340 meters. It was modelled after the Gelredome in Arnhem in the Netherlands.

"The pitch is basically only inside the stadium during matches. By relocating the pitch, we ensure optimum conditions for the sensitive green surface. The stadium stands are high and generally prevent direct sunlight. This has a noticeable effect on the turf, which would otherwise have to be replaced every few months with very expensive rolled turf," explains igus® CEO Michael Blaß. "And when the pitch is moved, our roller e-chains® are used for the power supply. They take up very little space and have proven their strength right from the start."

The principle of the mobile pitch is relatively simple. The 11,000 ton trough is pushed in and out of the arena like a drawer. To ensure that this works smoothly, 16 steel rails were embedded in the so-called secondary floor, the foundation. Each rail is 25cm wide and 300m long and is used to transport the trough and turfed surface into the arena.

Roller e-chains®: rolling instead of gliding

The igus® rol e-chain® is predestined for applications in which long travel distances have to be achieved at high speeds. Some examples include finish line cameras and conveyor technology. The system's low coefficient of friction can also save costs in slow applications in the crane sector or in shifting systems, as the dimensions of the drives can be significantly smaller.

At a speed of 1.5m/min. and an acceleration of 0.1m/s², two energy supply systems running in parallel are used in Gelsenkirchen for long distances of approximately 170 meters. To ensure the adjustment mechanism works, two shorter, approximately 4-meter-long energy supply systems are included as part of the overall concept.

"A key factor in this application is that the energy supply system must be weatherproof. It is essential that it works in all weathers," says Michael Blaß. "Then there is the high additional load in conjunction with the long travel. As a result of this combination, we switched from our normal chain to a roller energy chain. Here, the rollers are integrated into the side sections. As a result, the drive force required to move the cable carrier can be reduced by 75%. Wear is therefore significantly reduced. In addition, the rollers prevent the upper run from freezing to the lower run in winter. The chain worked perfectly right from the start under all environmental conditions!"