The National Transportation Safety Board sent Metro three urgent recommendations Wednesday regarding the ventilation of tunnels in response to the fatal smoke incident Jan. 12 in Washington, D.C.
In a letter to interim General Manager Jack Requa, NTSB said Metro should assess its ventilation system, write a procedure for tunnel ventilation and establish ongoing ventilation training for control center staff and emergency responders.
"Procedures for ventilation of smoke in emergencies can be critical, but they vary across systems, and in some systems are inadequate — as we have found in the present WMATA investigation,” acting NTSB Chairman Christopher Hart said in a news release. “Although the investigation is ongoing, WMATA should immediately address these issues to prevent any chance of a recurrence, and other systems should be audited for similar problems.”
Ventilation fans can operate in supply mode — pulling fresh air in to the tunnels and stations — or exhaust mode — pulling air out of the tunnels and stations.
At the L'Enfant Plaza station Jan. 12, the station and vent shaft fans were in exhaust mode, drawing smoke toward two stopped trains, according to the NTSB.
Also, two of four fans in a vent shaft tripped a circuit and were not operational.
The train stuck in the tunnel drew smoke inside because its ventilation was not turned off, according to the NTSB.
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Metro has already decided to allow train operators to turn off ventilation without first getting permission from the control center.
The investigation also found Metro does not have means to determine the exact location of a source of smoke, and its ventilation procedure Jan. 12 was inconsistent with best practices.
"We welcome the NTSB recommendations issued today and have begun to address these at Metro," Metro responded. "Following the January 12 incident, we conducted systemwide inspections and tests of all tunnel fan shafts and found them to be in good working condition. We also completed familiarization training for all 39 Controllers in our rail control center and we are reviewing additional protocols and training associated with tunnel fan use that are responsive to the NTSB recommendations issued today. We continue to give our full cooperation to the ongoing NTSB investigation."
Metro said it checks all fans monthly and there is a standard protocol for checking ventilation fans.
Hart, Requa and Metro Chairman Mort Downey briefed the Council of Governments about the investigation Wednesday.
Rep. Gerry Connolly said it is "stunning" that Metro would need NTSB to remind it that should have a ventilation system in working order.
Montgomery County Council member Roger Berliner said COG needs Metro to be at its very best, putting COG in a position to argue in favor of Metro.
Metro leaders raced out of the meeting when it ended.
Requa said that to his knowledge all fans in the system are working now.
The NTSB also sent letters to the Federal Transit Administration and the American Public Transportation Association calling for a nationwide assessment of subway ventilation.
