Four Metro subway trains broke down within 10 minutes yesterday afternoon and made hash of the evening rush hour.

"This is about as bad as it's ever been," said Joe Taylor, Metro's evening train superintendent. All four highly automated trains refused to run because their sensors detected brake problems. Inaccurate brake senors have been a recurring problem with Metro's $300,000 Rohr Industries subway cars.

At one point after the breakdowns, Taylor said, the Farragut West subway station was closed because it was jammed full of people and there were to trains to empty it. Trains had broken down about 4 p.m. at National Airport in the turnaround track, at Metro Center and twice at Eastern Market.

It took about 44 minutes before almost-normal service was restored on the Blue Line, Several trains were unloaded and turned back midway through the line to help alleviate the Farragut West problem, Taylor said.

Because of the double breakdown at Eastern Market, one of the tracks between there and the Stadium-Armory station was blocked with a stricken train for the rest of the rush hour. That meant that trains went to the Stadium every 12 minutes instead of every six, as scheduled.