Stand at the bottom of a silent, frozen escalator in a Metro subway station and you can hear grunts, curses and more than one dark theory about how the transit system is run by fools who can't grasp the basics of simple machinery.

Crawl into the cavelike space underneath that escalator and see the view from Metro's side: Decades of heavy use, design flaws and maintenance problems have flowed together to create the worst escalator crisis faced by any transit system in the country. It's also produced at least one negligence claim by the family of a man who died of a heart attack after climbing a broken escalator last summer.

And things are about to get worse before they get better.

Metro has launched a $112 million plan that calls for rebuilding nearly one third of its escalators--the worst 173 in the system--over the next four years. That will mean another 20 escalators out of service each day, in addition to the 50 or so now that are out of commission on a typical day, said Paul C. Gillum Jr., Metro's director of plant maintenance.

"There is no choice," Gillum said. "We either do this rehab or in a few years from now, we'll have complete stations closed because these units won't meet [safety] code."

Because its rail lines are so far below ground, Metro is the world's most escalator-dependent subway system, with 557 of the machines. The 550,000 passengers who ride Metro each weekday usually must take at least two escalators to get to a train.

Escalators have been breaking down throughout the system for much of this decade, but the problem has reached epidemic levels in the last couple of years.

Now Metro officials have begun to question the 1966 design of the subway stations, which left the escalators at street levels unprotected from rain, snow, leaves and debris. Those 119 exposed escalators, lauded by architecture critics, are among the system's worst performers, not working 50 percent of the time.

The repair program includes money to build protective canopies over a handful of those escalators, and Metro officials eventually may decide to put canopies over each exposed escalator as it is rebuilt. Long cool to canopies, Metro directors changed direction two weeks ago and told transit managers to make it a priority.

"The geniuses they paid 25 years ago couldn't figure out that if you stick these things out in the rain, you'll have problems," said Chris Zimmerman, a Metro board member who represents Arlington County. "If we know exposure to weather is a big part of the problem, I don't know why we're not out there, covering these things."

Water, salt and debris seep into escalator steps and handrails and wreak havoc with their electrical systems, said Cedric H. Watson, Metro's superintendent for escalator and elevator maintenance. Water on a handrail, for instance, can loosen belts that turn steps on an escalator. When belts are loose, an escalator automatically shuts off.

A rainy day can cause about 30 street-level escalators to shut down, Watson said. By contrast, the system's interior escalators, which connect mezzanines with platforms, don't go out of service nearly as often, he said.

Rehabilitating an escalator at about $300,000 is much cheaper than buying a new one for about $1 million, Watson said. To speed the repair schedule, Metro probably will have to close one entrance at stations with multiple entrances. The new program also includes money to upgrade elevators in Metro stations.

The reasons behind Metro's escalator meltdown vary depending upon who is asked. Maintenance workers blame the original design, while designers say poor maintenance is the problem. Meanwhile, current managers find fault with past managers and recent labor troubles.

David W. Couch, Metro's director of major capital projects, said age is the biggest factor. He noted that the oldest escalators, in service since 1976, have surpassed their 20-year life expectancy. The Bay Area Rapid Transit in San Francisco, a system roughly the same age as Metro, is rehabilitating all of its 120 escalators and just replaced 19 downtown, spokesman Mike Healy said.

But Watson said exposure to weather is the greater problem. "Our greatest main challenge is water," he said. "People don't believe it."

In a dark, damp concrete well beneath the base of the L'Enfant Plaza escalator on Seventh Street, Watson stood next to the steel undersides of an escalator as its steps rhythmically clanked past him.

On the wall, water marks reached about two feet high--vestiges from past floods where water rose up and lapped at the bottom of the escalator's steel frame. Rust has eaten holes in metal control boxes that house the brains of the escalator--the electric relays that control the movement of the staircase. When the relays get wet, they short-circuit, causing a shutdown.

A renovated escalator can last another 10 to 15 years with a canopy and about seven years without one, Watson said. The only escalators on the Metro system that now have canopies are those in the two newest stations, Columbia Heights and Georgia Avenue-Petworth.

But not everyone is convinced that more canopies are necessary.

Harry Weese Associates, the Chicago architecture firm that designed the Metro system in 1966, originally rejected canopies as too cluttered. "The idea was to make the entrances as elegant and dignified but unobtrusive as possible," said Stanley Allan, a Weese associate who is now retired.

Cleatus E. Barnett, who has represented Montgomery County on the Metro board of directors since 1971, defends the open escalator design. "I would not call it a bad call at all," Barnett said, adding that stations such as Judiciary Square have been celebrated for a dramatic, open-sky view that would be compromised by a covering.

Metro General Manager Richard A. White said the agency does not have enough money to erect canopies at every outdoor escalator. Couch is working on cost estimates but said canopies could cost $700,000 each.

Metro may not have much choice, however. Recent changes to the building codes in Virginia and Maryland now require canopies over any outdoor escalator that undergoes a major rehabilitation. The District does not currently require them, but Metro officials expect it will soon.

Metro officials acknowledge that management mistakes added to the escalator woes. In May, three newly installed escalators at the busy Pentagon station were shut down because of broken and cracked steps. The escalators, which cost $491,000 each, were made by an English firm that has since gone out of business. Two of the three have been fixed and are back in service; Metro is still working on the third.

Maintenance also has a troubled history. Two years ago, in a scandal that led to multiple firings, investigators found that mechanics had falsified escalator inspection reports, claiming to have performed repairs that were never made. Managers deferred maintenance and kept escalators running to give the appearance of a functioning system, said White, who joined Metro shortly before the scandal was unearthed. "It helped put us in a deep hole," he said.

Getting enough workers to make the repairs is another problem. Outside contractors maintained the machines until about six years ago, when Metro managers decided to use their own workers to save costs and increase control. That change sparked a "labor war" over union representation and has made it difficult for Metro to attract and retain escalator mechanics, White said.

If a union tangle wasn't enough, a vibrant regional economy has made it difficult for Metro to attract escalator mechanics, who earn more and get better hours in private industry. There are currently eight vacancies in Metro's 97-mechanic department. A consultant last year said Metro needed 124 mechanics to keep up with repairs.

To fill its vacancies, Metro opened its own training school to teach novices how to repair escalators and recently graduated the first class of 19 apprentices.

White said Metro has done a poor job of explaining the problems beneath its stopped escalators. "We've got the most escalators in the world, the deepest in the world and they're in bad shape," he said. "We're working like heck . . . but the customers aren't going to see results for some time."

The Ups and Downs of Escalator Maintenance

Metrorail depends on its escalators -- 543 of them -- more than any other subway system in the world. Seven days a week riders stand, walk, or sprint their way to the top and to the bottom of the moving stairs. With 550,000 Metro riders a day, the system takes a beating.

The greatest maintenence challenge for escalators is water.

Rain and snow can collect inside an escalator and cause problems. This is especially true for the 119 escalators that are not sheltered by a canopy. Unsheltered escalators are out of service 50 percent more often than covered ones.

Short-circuits

In many stations, control panels are not properly protected from water that might seep in from above. Over time, the metal casings around control boxes corrode. The moisture can cause short-circuits and damage wiring. Some escalators are being fitted with computerized control panels that are enclosed in a plastic casing to better withstand the elements.

In too deep

During a severe thunderstorm, as many as 30 exterior escalators can be down systemwide because of standing water. If enough water collects inside the bottom of the escalator, moving parts and belts can be slowed or get clogged by debris. In these instances, the water has no place to drain and must be bailed out.

Moving parts

The deeper an escalator, the more moving parts it has and the more routine maintenance it will need. In some escalators, mechanics have installed automatic greasers that keep the machine's parts lubricated.

Belts

Rubber belts often are replaced by chain belts for greater durability. Typical wear on rubber belts can cause them to slip, jam and break more easily than chain belts.

Drive system

Every 20 feet, a speed regulator and motor propels the steps. An escalator travels at 90 feet a minute.

Safety devices

A standard Metro escalator is equipped with at least a dozen safety devices that, when tripped, bring it to a smooth stop and lock the starting devices until the problem is corrected. Multiple devices ensure the system is safer, but this can lead to more shutdowns.

Not always broken

A stationary escalator does not always mean a breakdown in equipment. Often, internal escalators are shut down to help regulate the flow of pedestrian traffic in a busy station. In a bank of three escalators, the middle escalator may be turned off to give passengers the option of walking up or down.

SOURCE: Cedric H. Watson, superintendent, elevator/escalator branch of plant maintenance, Washington Metropolitan Area Transit Authority