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Gleaming glass palace

Life will soon be a lot easier for the window-cleaners at Berlin’s main station. Starting in May, the semi-automatic cleaning system Filius Toni will take over the dangerous task of cleaning the glass canopy roof. The cleaners can operate it by remote control from the platform.

The soaring glass dome of Berlin’s main train station illuminates the night sky on the far bank of the Spree. The glass roof is made up of over 8000 panes, no two of which are identical – the north-south glass roof alone is 200 meters long and the east-west roof spans another 278 meters. This attraction for tourists harbors numerous dangers for window cleaners. Hence, they need a special permit to climb onto the roof. As of May 2007, the window cleaners at Berlin’s main station will be able to sit back and relax. They will remain on the train platform with a remote control unit while the semi-automatic cleaning system Filius Toni keeps moving all over the glass roof according to their instructions, cleaning it from the ridge to the eaves. A complicated job: Countless obstacles – snow guards, supporting arches and ventilation flaps – border the cleaning machine’s path and the roof slopes nearly 90 degrees in some spots. “Filius Toni uses four large balloon tires and four wheel drive to navigate the obstacles without any problems,” explains Justus Hortig, who headed the development work at the Fraunhofer Institute for Factory Operation and Automation IFF in Magdeburg contracted by Deutsche Bahn AG. “What is more, the balloon tires distribute the pressure Filius exerts on the roof evenly on the glass.” To keep travelers safe, the cleaning unit is secured by a gantry, a kind of track system centered on the roof, from where two rope winches enable Filius Toni to descend. Lines and cable drums continuously supply it with water and power from the gantry. Filius descends and travels straight forward by remote control. If it comes up against a snow guard or some other obstacle, it initially stops, however – a requirement of the Deutsche Bahn AG. The operator on the platform has visual contact with Filius through the glass roof. Only when the operator transmits the signal by remote control to resume travel does the cleaning machine slowly roll over the obstacle. The operator also controls the direction in which Filius is supposed to travel. A broad roller brush and water spray nozzles quickly and spotlessly clean over 150 m² per hour. A human window cleaner manages around 20 to 30 m² per hour. Price is another of Filius’ advantageous features: “Filius can sharply cut cleaning costs that usually run to the mid five figure range,” says Hortig.


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