Boyd Wiles Jr. has worked only three out of the last 10 months. He was laid off from his work at the Mack Truck plant in Hagerstown from last December until April, called back and then laid off again in mid-July. He has not worked since.

That the 59-year-old Wiles is out of work is not unusual. Hundreds of his fellow workers at Mack Truck have been laid off and almost 11 million Americans were counted out of work in August.

For Wiles, however, and other men and women his age, unemployment is proving to be a growing and especially vexing problem. According to figures prepared for the House Aging Committee, workers 55 and older constitute the fastest growing unemployed group in the country. And, like Wiles, once they are unemployed, older workers find it particularly difficult to get back to work.

In his search for a job, Wiles, who was earning more than $26,000, has ranged as far south as Georgia and as far north and west as Pennsylvania."I don't know where else to go because nobody's hiring," Wiles said.

A machinist and sheet metal worker, Wiles tried every place he knew and even called factories he passed on the road during his scouting trips for a job. None of it has paid off. He found one position open in a Baltimore factory, but he lacked the necessary tool and die experience for the job.

He said his age weighs against him. "They don't want to train you due to your age," Wiles said. "They know you don't have that long to work. They just tell you that."

The current unemployment rate for workers 55 and older is 7 percent, still well below the figure for workers aged 16 to 24, who have the highest rate -- 19 percent, according to the Bureau of Labor Statistics. But Wiles and other workers his age constitute the group with the fastest growing unemployment rate in the country.

Since January, the unemployment rate for workers 55 and older has increased 24 percent, more than twice the 11 percent increase for those 16 to 24 and 50 percent faster than for the work force as a whole, for which the unemployment rate grew 16 percent.

And those older workers remain unemployed an average of 19 weeks, compared with 9.6 weeks for workers in the 16-to-24 age bracket, according to BLS.

In August, of the 10.8 million unemployed, 117,000 were 65 and older, and 771,000 were 55 and older. The figures for September, to be released today, are expected to show even higher unemployment.

According to Rep. Claude Pepper, chairman of the House Aging Committee, who has called hearings starting today to examine the problem, "Unemployment is so severe today that even the oldest and most experienced workers -- those who in better times are protected by seniority rights -- are being tossed off their jobs. Many of these older workers will be unable to collect their pension benefits because they are just short of the required years of service."

Unemployment obviously brings great pain to younger workers, who are trying to launch their careers and may have young families. But layoffs for older workers, coming at such a late stage in their careers, bring special emotional and financial problems.

The older unemployed worker, according to Johns Hopkins medical demographer Harvey Brenner, suffers two losses. First is the obvious loss of the job, income and position that comes with unemployment.

Second, according to Brenner, is the loss experienced when the older worker finally finds a job, usually not with the same company and sometimes in a different industry. "In our American economy people tend to expect that as one gets older, one achieves higher status," Brenner said. "If you are to work for a different company or industry, the seniority you've acquired, the salary you've acquired, the skills you've acquired and the status you've acquired all will be lost.

"In other words, you're moved back to a situation you experienced when quite a bit younger. And, essentially you've lost all those years of effort. That's the way it's experienced. That's the way it's felt."

A report by the House Aging Committee released yesterday notes that the same seniority system that tends to protect older workers from layoffs winds up hurting them when their plants are closed by hard times. "By the time these older workers hit the job market," the report says, "most if not all of the comparable jobs in the community have already been taken by the younger workers who were laid off earlier in the process."

"A younger worker sooner or later will make it," said Larry Smedley, associate director of the AFL-CIO's department of social security, "but an older worker who is in his 50s may never be an effective worker again. Once that older worker becomes unemployed, very often it's the end of the line."

Although older workers who become unemployed are more likely to have savings to fall back on and less financial demands on them, they also have less time in which to recover from an extended period of unemployment if they are planning to retire. Blue-collar workers, according to Smedley, tend to retire when they can.

Since older workers who become unemployed stay out longer, the chances are greater that they will have to spend savings.

And, Smedley noted, once workers are discharged from a job, "the accrual of pensions is stopped and what pension they've accumulated is being eroded by inflation so when they get it, it's not going to be worth that much."

In addition, the typical unemployed older worker who finally finds a new job can expect to have his annual salary reduced an average of $50 for each year of age -- $3,000, for example, for a 60-year-old -- according to the House Aging Committee report.

Robert Dorang, 61, of Wharton on Maryland's Eastern Shore, was out of work for three years before getting a part-time, minimum-wage job in a federally funded program that pays him $80 a week -- less than unemployment compensation pays and considerably less than the $35,000 to $40,000 he made as a production manager for a firm manufacturing television camera tubes.

"There was a period of time of very, very great depression," Dorang said. "And I got down to the very bottom. When the unemployment checks ran out and we ran out of our savings, I was at a real, real low ebb in my life." At one point, Dorang said, he considered suicide. "It's very difficult to think about at first, but after you think about it for a while, it gets less difficult," Dorang said.

Other older workers who find themselves out of work for the first time manage a stiff-upper-lip attitude. Joseph Gessler, 59, of Baltimore, has been unemployed since April 30 when the plant that he managed folded. "I've never been out of work before. It's depressing and a little disheartening," Gessler said, adding "I'm not discouraged. I'm confident I'll find a position. But I might have to relocate."

Gessler, who is still living on the severance he received when his employer closed his plant, has had eight interviews so far and one job offer. He considered the job inappropriate, however, and did not take it. His sights are set somewhat lower than the $49,000 and executive perquisites he received in his former job.

The older workers who remain unemployed too long ultimately give up looking for work and become categorized by BLS as "discouraged" workers. According to the BLS, some 334,000 workers 55 and up are discouraged.

Workers 60 and older are three times more likely to become discouraged than all other adults over 25, according to the committee report. When the older discouraged workers are added to those officially counted as unemployed, more than 1 million workers 55 and older are out of work.