avoid door elements that required electronic monitoring with the accompanying expensive maintenance. CE labelling was required, with the manufacturer assuming responsibility for the product's conformity [...] opening cycles. The material requirements were very strict. The stainless steel used with material number 1.4401 is an austenitic rustproof steel with outstanding corrosion resistance, whose surface was polished [...] absolutely secure against vandals. In addition, with a leaf height of 2.60 metres, a door width of 1.10 metres and a door leaf weighing more than 100 kg, enormous forces are generated that can also be