Metro has replaced dozens of insulators and is considering a significant expansion of tunnel sealant work after Tuesday’s major rush-hour disruptions on the Red Line.
In each of the three incidents — near Tenleytown in the morning, and near Dupont Circle and Van Ness in the evening — a single insulator was removed and replaced after power was shut down to the tracks, service was stopped and firefighters gave the all-clear.
“It was not good, and that’s nowhere near where we want to be, of course,” said Metro General Manager Paul Wiedefeld.
“I wish I could totally eliminate it — that’s what we want to try to do — but occasionally, we will have hiccups,” he said.
Since then, extra inspections and maintenance work have led to at least 52 insulators along that part of the Red Line, and Metro has renewed cleaning efforts, said Metro Chief Operating Officer Joe Leader.
The work also identified two new “heavy leaks,” where Metro is now using a hose to funnel the water straight into drains rather than allowing it to fall onto areas near the electrified third rail.
Besides the significant amount of water in the tunnels, particularly after heavy rains, Metro is also examining whether rail grinding work in August left extra metal dust.
Drains were clear in the area, but humidity, brake dust and steel dust buildup increase the risk of electricity jumping out of the proper path, a jolt known as “arcing.”
The long-term fix to water problems in this part of the Red Line is likely an expansion of major tunnel sealant work. The sealant remains under review in the area it was applied near Medical Center, and some additional leaks have been repaired there as part of warranty work.
Metro repair crews had some issues getting to the site of the smoke incidents, Leader said. “Responding to the incident was really difficult because of the rain and the traffic,” he said.
Despite Tuesday’s rough Red Line rides, Metro said things have improved from a few years ago. “The number of arcing insulators are definitely, without a doubt, coming down,” Leader said.