Because Metrorail operators do much more than push buttons and announce stations, they must pass a rigorous nine-week training program.

All 20 trainees at a recent session at Metro's New Carrollton office, for example, were given a set of facts about hypothetical emergencies, from subway doors that wouldn't close to smoke entering a car, and 10 minutes to discuss with classmates how best to handle them. Then, one by one, the trainees -- all former bus drivers -- got up in front of the group and acted out the scene. Throughout, a tape machine recorded every word.

Instructor Harold E. Lambert, 46, who started as a bus driver about 23 years ago, took the part of "Central Control" -- the office from which all trains and their operators are monitored. Other class members later critiqued colleagues' performances.

Trainees practice making routine announcements: greeting passengers at the start of a line; identifying the color and destination of that line, plus transfer points; noting names of approaching stations and the side on which doors will open. All this is also taped, and evaluated for accuracy, clarity, proper pronunciation and overall style. Although it is unusual, some candidates, says Lambert, have washed out of training school because of inadequate announcing skills.

Operators are assigned to specific lines and consequently repeat the same 11 to 22 announcements (depending on the line) as many as 450 times during their eight-hour shifts. Some of the more creative (or perhaps bored) occasionally try to ad-lib.

While some individual variations are permitted, Connie Williams, acting head of rail training for Metrorail, says "inappropriate" or "overly enthusiastic" announcements are unacceptable. Williams often rides the lines "undercover," and evaluates performances.

About 250 Metrorail operators are currently on the job, according to Lambert, with 60 students training for positions to open up in December when the Red Line is extended to Shady Grove. He estimates that over 90 percent of the subway operators are men.

The reason, he says: Applications for the switch from bus to rail work are accepted on the basis of seniority, and there are many more male than female bus operators. The youngest trainee so far was 25; the oldest, 56.

Every subway operator has to memorize a series of several hundred rules -- general safety rules and specific operators' rules -- plus "the bible," a manual of standard operating procedures which the operator carries with him daily. The operator has to learn the location and function of all Metrorail equipment and how to identify -- and try to resolve -- any problem that may arise.

"I didn't know what I was in for," said Metrorail trainee Thomas Ellis, 33, who has 12 years of experience driving a bus and was surprised at how hard students have to work. "I study four, five hours a day."

Some operators mention the additional pressure of being in charge of a series of subway cars, each weighing 75,000 pounds -- when empty -- and moving at speeds of up to 75 miles per hour, largely underground.

Ron Wingo, 41, a bus driver for 12 years, was hesitant at first about driving through the subway tunnels and going over the bridges. "But like everything else, after you do it a couple of times, it just doesn't bother you. Now I enjoy the tunnels."

And as Lambert points out, operating a subway entails "a different degree of responsibility" from a bus. Each car is worth about $250,000 and if it breaks down, the driver cannot simply abandon the train and call Central Control to send out a mechanic.

"They teach you to be constantly aware of what you're doing," says Wingo. "When you're dealing with millions of dollars, and -- in rush hour -- up to 2,000 people on an eight-car train, that's a big responsibility."