TriMet maintenance crews worked overnight to successfully replace the surge arrester that led to Monday’s MAX disruption in downtown Portland. TriMet is reviewing the incident and looking into whether any changes are needed for system reliability. The incident began at about 5:30 a.m. Monday morning when we had six power substations go down. By 8:42 a.m. technicians were able to bring most of the substations back on line. By about 5:30 p.m. TriMet technicians and engineers identified a surge arrester had failed. Crews were able to make a temporary repair and the power was restored by about 6:45 p.m. and MAX trains were once again crossing over the Steel Bridge.

There was a separate outage Monday evening involving a train and several substations.  Crews inspected the train involved in Monday evening’s disruption on the west side and found an issue inside the traction motor. The electricity inside the motor arced and caused a high current surge that led the vehicle and the nearby substations to lose power. The motor is being replaced and the rest of the train’s systems are being inspected. Once that is completed, we will determine if any additional maintenance or inspection is necessary.

This disruption began at about 5:50 p.m. Monday. The MAX system lost power between Beaverton Transit Center and Sunset Transit Center when the train incident occurred and six substations in the area went down at once. Technicians were able  to restore power by about 6:50 p.m. Numerous efforts were made to get the incident train moving, but they were unsuccessful and another train had to tow it to our Elmonica Rail Maintenance Facility in Beaverton. The incident train was off the main line by about 8:15 p.m.

The same vehicle was involved in an incident Sunday at about 11:45 a.m., also on the west side, that led to six substations losing power but then immediately coming back on line. At that time, there was no indication that the train had caused the issue. We now know the issue with the traction motor led to this incident as well.