Fred Dryden operates an excavator for the heavy division of Barletta Cos.' reconstruction of the 97-year-old Larz Anderson Bridge near Harvard Square in Cambridge, Mass. At 60, there is a good chance he's older than some of Boston's infrastructure. As an operating engineer, he has managed to avoid many of the physical hazards to which other construction crafts are prone and plans to stay on the job until age 65.

"I like my work because I'm always doing something different," he says with a smile. "I've got wheels, so I can go everywhere."

For all his years in the industry, Dryden should also consider himself lucky to have limited his work-related injuries to a single sprained ankle. However, craft workers in many of the most punishing trades—such as carpenters, ironworkers and tile setters—find that chronic physical problems have turned the years after age 50 into an endurance contest with pain.

Researchers say the wear and tear on a construction worker starts early, sometimes with one or two injuries, and accumulates over time.

A proactive approach to first injuries could mean fewer second injuries, fewer chronic musculoskeletal conditions and, eventually, a healthier generation of construction workers who can remain in the industry until they can retire in their 60s with full benefits. After the baby boomers put away their tools—which CPWR researcher Sue Dong says will happen within the next 10 years—the industry is going to need new younger workers to keep working as long as possible.

Data from the U.S. Labor Dept.'s Current Population Survey supports that prediction. By 2020, in a variety of trades, the industry will need 324,000 more workers to accommodate growth and replace outgoing staff.

Keeping the older workers in one piece may help fill some of the potential shortage. Other than scrapes and scratches, Bill Frost, a 58-year-old member of carpenters' Local 218 and a resident of Salem, Mass., says he has avoided major injuries by following some sound advice. "I can remember a roofing job when I was a kid, and an old-timer I was working with said, 'You just went up the ladder with three bundles on your right shoulder all in a row. If you keep that up, you'll be so completely deformed in 15 years that your body with be pulling itself apart. You go up with one at time—first, a bundle on the left shoulder. Then, you go up the next time with one bundle on your right shoulder.' "

These days, such practices are called ergonomics. Says Frost, "I always try to teach the kids that, 99% of the time, the easy way is the best way. You don't need to burn yourself out proving you can do the job."

Tom Bertochi, 56, is general foreman for contractor J.F. White in Boston and a member of electrical workers' Local 103. A resident of Marlborough, Mass., he says years of electrical work have led to chronically sore knees and ankles. But as a foreman, he has traded physical stress for mental stress.

Not everyone who perseveres takes a foreman's job or operates equipment. A member of the painters' union in Minnesota for 56 years, glazier Earl Erickson, 79, had retired 17 years ago at age 62 but soon returned to part-time work for a Minneapolis commercial glass installation firm. The extra money comes in handy for his grandchildren. Erickson says he's lucky because he keeps in shape, has never had a serious fall or needed knee replacement surgery, and has no arthritis.

"My back's still OK," Erickson adds. "I'm really the minority."