NORTH KINGSTOWN, R.I. -- The specially fortified buses with reinforced windows rolled toward the giant factory on a cold morning in March 1982. More than 800 strikers shouted curses; some hurled rocks at the replacements who were coming to take away their jobs. Finally, in desperation, scores of strikers did the last thing they could to try to stop it: they lay down in the road, trying to block the buses with their bodies.

State and local police quickly moved in, spraying pepper gas on the huddled strikers. Within minutes, it was over.

Brown & Sharpe Manufacturing Co., one of America's oldest and largest makers of machine tools, was open for business again on March 22, 1982. After 40 years as a unionized manufacturer producing world-renowned high-precision industrial machinery, Brown & Sharpe had begun to deunionize.

Today, Brown & Sharpe operates profitably on a nonunion basis.

The company had accomplished what most Rhode Islanders thought could never be done in the heavily unionized industrial state: It used strikebreakers to replace a work force of 1,600 members of the International Association of Machinists, the largest local union in the state.

The Brown & Sharpe conflict, which technically continues today as the nation's longest-running strike, was not the most publicized, the most violent, or even the most significant of labor's setbacks in the 1980s. But looking back on it, union leaders see it as an archetypical labor-management conflict of the decade.

The conflict exhibited all the symptoms that have made life so difficult for the modern labor movement: management with its back to the wall because of foreign competition; workers more easily replaceable than anyone realized, thanks to high unemployment and new computer technology that had "deskilled" the jobs once done by master craftsmen; a local union that was once a powerhouse, in a classic union state, seemingly helpless in the face of management militance.

From the gleaming office towers of metropolitan Washington, to the giant meatpacking plants of Iowa, from the small shoe factories of New Hampshire to the suburban business parks of California, America is being slowly weaned from union labor.

The replacement of strikers, a rare phenomenon in post-World War II labor relations, is becoming commonplace. Major employers such as Continental Airlines, Trans World Airlines, Greyhound Corp., Phelps Dodge, Iowa Beef Processors, Magic Chef, the Chicago Tribune Co. and many others have done so, in many cases permanently ridding themselves of union members. The willingness of management to take this ultimate step has had a chilling effect on unions.

In an earlier day, it would have been easier for labor to use aggressive organizing campaigns to recruit new members and recover from such setbacks. But that, too, has changed. In the 1960s and much of the 1970s, unions waged election campaigns at 6,000 to 8,000 companies every year, winning 50 to 60 percent of the time, and gaining up to 200,000 new members a year.

But union organizing now has become so difficult and costly that by 1983 unions conducted only 3,200 elections, winning only 47 percent of the time and recruiting 36,000 new members, a post-World War II low, although union organizing has picked up somewhat since then.

In the past decade, the number of Americans belonging to unions has declined from about 24 million to less than 20 million. That's a 16 percent drop, even while the work force was expanding by 20 percent. Today, there are many more former union members than current members in the work place.

At its high point in the post-World War II economy, unions represented 35 percent of the work force; the unionized share has now dwindled to 17.5 percent.

The deunionization of Brown & Sharpe was just one in a series of shocks administered to America's labor movement in the past decade -- a decade that could well turn out to be the worst in the modern history of organized labor.

The decline of labor unions is part of an upheaval in the work place. That upheaval reflects the most intense global and domestic economic competition of the century, intense antiunion activity by U.S. management, and less desire by many workers to belong to unions.

The new antiunionism by management has presented major problems for organized labor. At least 10,000 workers a year are fired -- often illegally -- during union-organizing efforts, and roughly one of every three workplace union elections is tainted by illegal activities by management, according to National Labor Relations Board data and surveys by the AFL-CIO.

Even when unions win workplace elections, they often face tough bargaining, and an estimated 35 percent to 40 percent of such union "victories" never result in a lasting contract.

But many other firms confront unions with a different kind of problem. These companies have followed the lead of major nonunion corporations such as Motorola Inc., IBM Corp., and Marriott Corp. and have developed elaborate "human resources" programs that are designed to make them "enlightened" employers. These personnel policies often diminish workers' desires for unions, and such firms, union officials acknowledge privately, are virtually impossible to unionize.

The downturn of once-powerful unions has contributed to lower pay and benefits and lessened job-security for millions of workers -- both union and nonunion. The loss of economic clout by organized labor has contributed to the erosion of real income for many in the middle class. In the work place, the balance of economic and political power has shifted in favor of employers.

The trend is part of a larger shift in the very nature of work in America, a dislocation that is permanently eliminating millions of full-time manufacturing jobs, creating new high-technology and service-industry jobs that are highly paid for a relative few, but is resulting in often "deskilled," poorly paid, part-time and temporary jobs for the many.

"The United States alone is undergoing a significant deunionization," Harvard University economist Richard B. Freeman told a House labor-management subcommittee last year. While other Western nations have had relatively marginal union declines, he said, none approaches the magnitude of the United States, where the union share of the work force has been cut in half.

A number of dramatic events and underlying causes of union decline stand out. The Reagan administration's 1981 firing of 11,400 air traffic controllers for an illegal strike set a tone for management militance in the 80s. More than 10 million industrial jobs, many of them unionized, were permanently lost primarily because of lower-wage foreign competition. Most new jobs are in the "service economy" -- banking, insurance, computer and business services -- the very areas where unions have no roots. And deregulation of key industries such as airlines, trucking and telecommunications has set off a frenzy of cost-cutting and consolidation that has crippled once-powerful unions.

The consequences of the union decline touch both union and nonunion workers. Diminished union membership means weaker bargaining power and smaller wage gains -- not only for unions, but for nonunion workers, whose pay often is influenced by prevailing union wages in each region.

The traditionally unionized blue-collar industrial job that paid $20,000 a year or more, supporting a middle-class life style, is a vanishing job. Many firms in the heavily organized manufacturing industries such as autos and steel have turned to "outsourcing."

In the auto industry for example, companies have been able to cut their work forces by obtaining cars, engines and other components from outside nonunion sources, often overseas. General Motors is currently shutting up to a dozen plants employing 35,000 people, while planning to import up to 400,000 vehicles and one million engines from an increasing number of foreign GM plants in Mexico, Europe and elsewhere.

For many hard-pressed employers, the full-time employe with fringe benefits has become an expensive luxury. Companies are instead relying more heavily on part-time and temporary labor -- the so-called "contingent" workers who constitute an estimated 15 percent to 20 percent of the work force. Companies have also increasingly turned to "contracting-out" much of their work, usually to nonunion subcontractors with lower labor costs.

With the loss of membership has come a loss of economic and political clout that may be even worse than these statistics reflect "because unions have lost their claim of legitimacy for speaking for the labor force at large," said Richard Edwards, chairman of the economics department at the University of Massachusetts.

"When they represented one-third of the labor force, there was the sense that they could speak in broader political arenas. When they put forward an agenda for socialized medicine, Social Security, occupational safety and health, and mine safety, those were not programs for the special interest of union members alone. They spoke on behalf of the entire work force," Edwards said.

"But ... they are increasingly being put in the role of agents for special interest -- meaning those workers who are unionized," he said.

There are several bright spots for unions, however, particularly in the success of organizing unions among government employes. While private-sector union representation declined from 35 percent to 16 percent, public sector unions have flourished as state and local laws opened the door for unions since the 1960s.

Public sector union membership has climbed steadily to more than 33 percent of government workers, and, in the process, the public-sector unions have become some of the largest and most powerful: the National Education Association, the American Federation of Teachers, the American Federation of State, County and Municipal Employees and the Service Employees International Union collectively represent four million government workers and, due to aggressive organizing, have expanded membership.

Unions have also made some small gains among female workers, recruiting 70,000 new members in 1986, although the 5.8 million female union members represent only 13 percent of all employed women.

At Brown & Sharpe, in retrospect, union officials criticize themselves for being unaware of how times had changed and how determined the company was to prevail.

"The signs were there. But I don't think we could see the signs, that they would ever do this," said John Coen, 46, the local union president.

"At the time, we thought it was just another strike. But in retrospect, I think we should have seen that it was the tip of an iceberg that was on the way," said William W. Winpisinger, international president of the 700,000-member Machinists.

Brown & Sharpe made the world's finest precision machine-tools -- the giant milling and grinding machines that, in turn, are used to make other machines. At the end of the boom period of the 1970s, its sales peaked at $157 million and profits hit a record $18 million.

The skilled machinists shared, to some extent, in that profit. They earned wages of $7 to $9 an hour. Fattened by overtime, some paychecks totaled $20,000 to $25,000 a year, a handsome wage by Rhode Island standards: enough for a house in the suburbs, perhaps a second car and a small boat for weekends on Narragansett Bay. A Brown & Sharpe paycheck also meant rock-solid job security.

By the early 1980s, however, Brown & Sharpe was facing a crisis, as was the entire industry. Lower-cost imports, primarily from Japan, West Germany and Switzerland, were taking a growing share of the American market.

The seeds of the labor conflict at Brown & Sharpe may have been planted when Donald Roach, the company's president and chief executive, visited Japan in 1978 and glimpsed a dark future for American machine tool manufacturers. The Japanese had gotten the jump on the American firms and, with the help of their government, were producing computerized "numerically controlled" machine tools that would soon be delivered worldwide at a price cheaper than Roach's company could produce.

The company decided to reinvent itself by partially giving up its old-line business and turning to metrology, the production of high-accuracy advanced measuring devices. It also began making computerized process-control robots with prices starting at $180,000 each. Instead of a traditional machine shop, it would eventually become a company where engineers and computer programmers outnumber machinists, and where managers outnumber hourly workers.

The change meant that Brown & Sharpe -- which had helped generations of Rhode Islanders learn skills and earn their way to a middle-class lifestyle -- would need people with different skills.

Before any of the major changes could be undertaken, the company and the union had to negotiate a new labor contract to replace the one due to expire in October 1981.

Seniority was the crucial issue, in the company's view, because a previously negotiated system of "machine seniority" gave veteran workers the right to choose which machines they worked on and gave workers a virtual veto power over transfers from machine to machine.

There were certain issues that "stood in the way of moving this company into a position to effectively compete with foreign competitors," Roach said. To management, the need for flexibility in assigning and transferring workers was a pivotal issue, "a strike issue," because of estimates that productivity could improve by up to 20 percent in some departments if management had complete control.

"We were not mad at our employes. We were not mad at the union. We had our backs to the wall," said Richard E. Jocelyn, the company's labor relations director, explaining why the firm was willing to take a strike to win the change.

Seniority was equally crucial to the men and women of the machinists union. Seniority was a hard-earned right to them, a privilege earned by decades of work in the shop. Veteran workers could pick their own machines, and, as they approached their fifties and sixties, as many of them had, they could work on the easiest or most pleasant jobs.

"Seniority is something that is sacred. Nobody can hand it to you. It is something you had to earn," said Charles Thornton, 67, who had worked in the shop since just after the attack on Pearl Harbor. "The senior man had the first shot at job openings, the best protection from layoff, and preference on his shifts," Thornton said. "When you threaten seniority, it threatens the lifeblood of a union."

Twice before, during the fat years of the 1970s, the IAM had struck Brown & Sharpe, and both sides agreed that the union had won each time. Sales were booming then and the company made concessions to avoid a decline in profits that a prolonged strike might bring.

But as the expiration of the contract approached on Oct. 19, 1981, Roach recalled, "Our business was down, and we could take a strike."

For several months after the strike began, Brown & Sharpe operated with just its supervisors and a few employes willing to cross picket lines, and -- thanks to new technology -- found it easier than expected. "The union used to say they had these skilled people who were irreplaceable, and we used to believe them," said Jocelyn, the director of labor relations. "Now we have operators who set up the machines, feed in the parts, and push a few buttons."

As the strike wore on, Brown & Sharpe also began selling off much of its old machinery, shipped much of its production to its overseas plants in Britain, West Germany and Switzerland, and it vacated and leased out some 150,000 square feet of its factory as a Sears warehouse. The new Brown & Sharpe was taking shape.

Every morning for four years, an ever-dwindling number of strikers doggedly picketed Brown & Sharpe; every week they collected strike benefits from the union. Finally, in August 1985, the IAM -- suffering a financial drain of more than $1 million a year in strike benefits -- formally withdrew the picket line. But the strike technically continues pending the outcome of the charges filed by the union against the company at the National Labor Relations Board.

The NLRB general counsel would later charge that Brown & Sharpe resorted to illegal tactics during those labor negotiations by deliberately demanding concessions from the union that the company did not need for economic purposes, but which Brown & Sharpe knew would damage the union and possibly cause a strike.

The company strongly denies the charges. The NLRB charges, some of which have been dismissed, are still awaiting a hearing by the full labor board. The charges could result in the reinstatement of strikers and the awarding of back pay.

NEXT SUNDAY: The programs of organizing.