Four times in four days, Portland's light rail has failed. That has to be some kind of record. Amusingly, yesterday's failure hit just 20 minutes after some flack at the development agency known as Tri-Met took to Twitter to apologize for the outages that occurred on Monday, Tuesday, and Wednesday. But in their defense, temperatures had rocketed into the upper 70s by noon yesterday.
Wednesday, trains on the Green and Yellow lines near Portland State University were stalled by high temperatures causing an overhead wire to sag a bit, which led to extra tension on a contact line that helps guide a train's pantograph.
Goldilocks light rail: too hot or too cold, can't run. It must be Just Right.