Hamburg: Passenger compartment entry/exit doors in public transport vehicles
In this example, the Hamburg HOCHBAHN AG in their DT4 subway vehicles of the 1st and 2nd type series, a clamp detection is installed later in the pneumatically operated passenger doors. There are 50 vehicles and four carriages with a total of 800 double sliding plug doors. The average number of opening/closing operations per year and per door is around 50,000 Due to buckling movements in the area of the pivot bearing, initial problems developed with a copper-based cable in an operation period of 6 months, which prompted the HOCHBAHN to look for an alternative cable. The chainflex® CF98 control cable presents a potential solution. The alloyed cable used here is softer in its molecular structure and therefore is not inclined to embrittlement during bending load; the operating time increases. The control cable accomplished 450,000 door cycles without any interruption and error message at the HOCHBAHN rig testing. All vehicles were retrofitted thereupon in the course of the past year. No more failures were recorded since then. From the positive results of the rig testing, the HOCHBAHN - inspite of the high stressing capacities on the cables in the pivot bearing area - can have a minimum trouble-free operation time of 20 years.