Statement from Metro GM on 6/22 Accident
Our testing has resulted in our being able to replicate the problem, but not isolate the specific cause. We know the problem is in a track circuit. We could just replace the parts, but we need to understand what caused it. You don’t just change the parts. We must find the cause.
We have conducted computerized analytical tests, which the NTSB has referenced as “track circuit data.” The data establishes a profile of what’s taking place electronically in the rail system. These tests are normally conducted monthly. What we found during a special review of the data after the accident was that the track circuit periodically lost its ability to detect trains. This is not an issue that would have been easily detectable to controllers in our operations control center. What the analytical profile showed was that the track circuit would fail to detect a train only for a few seconds and then it appeared to be working again. This happened after we had replaced an “impedence” or “weezie bond” for the track circuit for where the accident occurred. The device communicates information such as speed and distance between the tracks, trains and operations control center. The device was replaced as part of Metro’s normal track rehabilitation program. We are now running analytical reports on the rail system daily instead of monthly and system wide. We have found no other similar issues with track circuits in the system.
Again, I want to stress that we will do everything we can to find the cause of this accident, and from what we have discovered so far it appears to be a freak occurrence.
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Labels: Transportation + Infrastructure
