Rep. Herbert Harris (D-Va.) charged yesterday that some heavy metal doors that would provide an emergency escape route from Metro's subway tunnels have been improperly installed and would be difficult to use if needed.

Harris made the accusation during a hearing called to examine Metro's fire safety program in the wake of a small trash fire April 16 that caused an hour-long delay to subway service between Virginia and Washington.

John J. Flynn, metro safety director conceded, "There have been some problems with the doors -- and we're still not satisfied." Richard S. Page, Metro's general manager, promised the committee a full report on the door issue by June 1.

There are 26 escape hatches in the 33-mile-long Metro system now in operation. They are located at underground stations that have only one exit or in sections of tunnel that are more than 2,500 feet from a station.

Lawrence Engleman, Metro's fire protection coordinator, said in an interview after the hearing. "I think it's important to note that there isn't a single fire door out there that cannot be opened. Some of them do not open as easily as they should."

One that did not open easily recently was at the Capitol South station. Englemand, accompanied by a Harris staffer, walked up to the hatch, opened a door, and found a chain suspended acros the pathway -- an impediment to hasty exit.

"I'd like to know why Metro paid contractors for incorrect installation of escape hatches," Harris said. Page said the report would address that question.

Most of the hearing was spent explaining the events of April 16, when a small trash fire blamed on careless smoking by a Metro maintenance worker, started in a pumping station located in the long tunnel under the Potomac River.

Smoke was reported in both the Rosslyn and Foggy Bottom stations on each side of the river. The source of the smoke could not be pinpointed until a supervisor stopped a passenger-carrying train at the pumping station and located the fire. Subway service was disrupted for about an hour while the blaze was being extinguished. No one was injured.

About 10 minutes were lost, Page said, when a Metro employe at the Rosslyn kiosk misread his smoke-alert panel. The smoke-alert system has been the source of false alarms throughout the rail system since the day train service began.

As a result, Page and area fire officials at the hearing said, whenever an alarm is activated, Metro officials check to see if there is a fire and to determine its severity before calling fire departments.

R. S. Carpenter, deputy Arlington fire chief and a spokesman for area firemen, said that such smoke-detector problems were common in high-rise buildings and other new facilities.

Page defended the decision of Metro supervisors not to close the system until the existence of a rail fire was determined. "I want to stress emphatically," he said, "that under no circumstances would Metro send a train with passengers aboard into a tunnel whee there was a known fire."