A Wee-Z bond similar to those used by WMATA. This is from the Charlotte North Carolina CATS Lynx Light Rail
On Jan. 22, Orange and Blue line trains were single tracking through the Rosslyn tunnel for pretty much the entire day because of "unscheduled track maintenance." That was the only description we could find from Metro at the time of the event.
A source inside Metro revealed a few more details.
Basically, a piece of track equipment--a diesel mover--got caught up in some other equipment, and that equipment was dragged and knocked through the tunnel destroying or badly damaging 11 track circuits along track 1, they said.
Track circuits, also known as Wee-Z bonds, are vital pieces of equipment that, for one thing, convey information about the whereabouts of trains along the tracks.
After wreaking havoc in the tunnel, the diesel mover eventually derailed, they said. No one was injured.
According to the source, the incident led to "a lot of work and territory to cover."
How was something causing this amount of damage allowed to go on for as long as it did?
The source did not know, but said it's likely that in Metro's Central Control, where trains are monitored and guided, someone "should have seen a row of indications on their main display telling them that track circuits were showing occupancies and staying occupied."
That apparently did not happen.
Over 24 hours, an internal email said, Metro track crews scurried to fix the damage, which was characterized as an "emergency." According to the source, lots of overtime was racked up as well.
Unsuck asked Metro about the incident, and after several days of prodding, this is what they said:
"A track buggy that was being used to transport rail parts to various locations Friday night was returning to the yard when it derailed early Saturday. There were no injuries. We single-tracked Blue and Orange Line trains while we removed the vehicle and made some track repairs. The equipment will undergo a complete inspection before it is returned to service."When now permanent GM Sarles was appointed interim GM, he said "I don't want to hide problems. That's the worst thing you can do."
Do you think Metro should have been a little more forthright with the public about what appears to have been a costly breakdown of Metro's "culture of safety?"