Baltimore transit agency unveils subway closure details

Unexpected rail wear led to last week's systemwide closure of the Maryland Transit Administration's (MTA) subway network in Baltimore.

Inspectors found that the gauge face angle (GFA) — a factor used to calculate rail wear —exceeded internal standards on 11 sections of elevated track. GFA is the measurement of wear that occurs on the part of the rail that comes in contact with trains' wheels.

As wear occurs, the gauge face of the rail goes from vertical to sloped. Exceeding these standards can lead to derailments, MTA officials said in a press release.

The agency announced the systemwide closure Feb. 11 but didn't go into detail about the rail problems. The system will remain closed through March 11 as crews complete emergency repairs.

"When presented with GFA findings in addition to a physical inspection, we found that the rate of wear was greater than anticipated," said MTA Administrator Kevin Quinn. "As a result, we took immediate action to protect our riders and initiated rail replacements at an accelerated schedule."

MTA also has published the physical inspection report that precipitated the closure. Completed by HNTB Corp., the report recommended immediately initiating emergency repairs on the subway system.

In addition, the document suggested that MTA evaluate its current training practice for track inspection and consider expanding the program to include both classroom and field training. The report also recommended that MTA review its rail lubrication policy.