Reporting from San Francisco -- Jerry Lee ran his battered hand along the side beam of a 35-foot extension ladder.

This particular workhorse of the San Francisco Fire Department — from Truck 5, Station 5 — was showing serious wear and tear. It had been dropped on the job in the middle of January and could no longer be trusted to bear a firefighter's weight.

"There's a crack they're concerned about," Lee said, tracing the offending scar with his thumbnail. "I'll open the break so I can get some glue in there. Then I'll clamp it back together.… If they don't destroy the ladder, I can repair any part of it, and it'll go out as good as the day it was built."

Only two dozen or so fire departments in America still swear by wooden ladders for their strength, safety and durability. Most are in California, and all but one buy their climbing gear from a company in Chino. The lone holdout is San Francisco, which still manufactures its own.

The department's 400 or so ground ladders are made of old-growth Douglas fir, harvested from eastern slopes in the Pacific Northwest, where limited light makes the wood grow dense and strong. All of them have been built or refurbished by a three-man crew with singular skills.

Those same men also turn out the 163-year-old department's metal nozzles and hose couplings, its hydrant wrenches, fire bells and the ornate eagles that adorn them. They build and maintain 13 types of ladders and track the department's long-lived inventory in a linen-bound book nearly a century old.

And when firefighters come up with ideas to improve equipment — a redesigned forcible-entry tool or a pressure-reducing valve for fire hydrants — their sketches end up in the drafty shop between the wholesale produce market and San Francisco Bay.

At least they do now.

The shop's patternmakers, Lee and Qing Du, are nearing retirement. And the city has yet to engage in the lengthy process of finding and training successors. Within a year, refinisher Peter Misthos could be left alone to carry on the San Francisco tradition.

Ladder-making is "part science, it's part art, it's all craftsmanship and experience," shop supervisor Michael Braun said. "To find replacements for gentlemen like this is not easy."

In the wood shop, perfumed by pitch and lightly coated with a fine layer of sawdust, Braun sorted through a stack: There are boarding ladders for fireboats, with hooks designed to fit over a gunwale; 50-foot extension ladders to scale the sides of multistory buildings; and so-called baby extension ladders for access to the attics of old Victorians.

Most fire departments switched to aluminum ladders half a century or so ago, Braun said, because they are cheaper and require less maintenance. Some firefighters believe that the metal models are lighter and easier to handle.

But handcrafted wooden ladders live on in San Francisco in part because of the city's uncommon combination of geography, architecture and urban design.

Old, wood-framed houses stand cheek-to-jowl. The streets are narrow and twisty, and many run beneath a canopy of electrical wires that power buses, streetcars and trolleys.

"A wood ladder," Braun said, "does not conduct electricity. In case you have a ladder up and you were to strike a live wire, you won't get electrocuted."

It's a danger that retired Battalion Chief William C. Peters of the Jersey City (N.J.) Fire Department understands all too well.

In the 1990s, Jersey City firefighters were called to a blazing tenement. People were trapped on the third floor, screaming for help. As two rescuers struggled to hoist an aluminum ladder in the snow, a third firefighter jumped in to help. When they swung the apparatus toward the building, it struck a 4,800-volt primary power line.

All three firefighters were hit with a jolt of electricity, Peters recalled. One of the men died. Another lost toes and a finger. The third was blown clear. "His heart rhythm was screwed up for a while," Peters said.

Longevity is another plus for wood. Although the life of an aluminum ladder is 15 to 20 years, Braun said, San Francisco's oldest wooden ladder still in continuous service was made in 1918.