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Due to the ongoing tram shortage, Zurich will thin out the network. Libe 17 will be eliminated and substituted by changing the routing of lines 6 and 10. Line 15 will see its frequency reduced to 15 minutes. Line 8 will once again have about every second tram a low-floor unit, albeit most likely just a "Sänfte" (old Tram2000 unit with low-floor section) to use the Cobras on the more demanded lines. These changes will go into effect on the 25th of November.
I do not know if the Mirages will remain in service, but it's highly likely that they will at the very least remain on standby.