If you're an ironworker on the Golden Gate Bridge and your home phone rings at 3 a.m., you know it's trouble.

You know someone is threatening to jump off your bridge. Your stuff is always ready; you're out the door in minutes.

If you aren't too late, if you climb out onto the cold steel and sweet-talk some poor lost soul off the beam or tower or manage to wrestle him or her to safety, it's a good feeling. Many suicide attempts are impulsive; lives can be salvaged.

If you fail, if the person jumps into that bottomless fog, it ruins your day.

"There's no describing how helpless you feel," says Ken Hopper, a Golden Gate Bridge ironworker for 17 years.

These ironworkers are tough guys. Men of Steel, they're called. Cowboys in the Sky. They fix and maintain the world's most amazing Tinkertoy.

But what qualifies these blue-collar rivet-wrestlers to perform the delicate psychological task of suicide prevention? Just this: There's nobody else.

"We're the only ones dumb enough to do it," Hopper says.

They're the only ones with enough equipment, knowledge of the bridge and courage to go over the rail.

The suicide rescue duty is voluntary, but the bridge's ironworkers all take their turns.

There's almost no danger of falling, but it's not a risk-free gig. One man pulled a knife on an ironworker. A loaded gun fell out of the pocket of another guy. An ironworker was bitten by a woman he pulled off the bridge.

But the iron cowboys answer the call, late at night or during their shift. At least two of them go out on every rescue. They give it their best shot, and the weird thing is that they wind up being pretty damn good at the psychological stuff.

Sometimes a police psychologist will be at the scene, coaching the ironworkers by radio. More often, the rescuers are on their own. I asked Hopper if the workers are given any suicide prevention training.

"Over the years, (suicide prevention experts) have come to give us seminars, " he says. "They wind up asking us questions, because all they do is talk to these (suicidal people) on the phone. We deal with them face to face."

Often a would-be jumper is locked into a private mental zone and the trick is to get his or her attention. Some tricks that have worked:

Hey, if you're going to jump, at least give me your mom's phone number so I can call her to tell her.

That's a nice watch. If you're going to jump, can I have it?

Sometimes the trick is simple compassion, the voice of a human who cares. Look, I've been through some real hard times myself. I know it's possible to get help.

Hopper estimates he has talked or wrestled down about 30 people, and lost two.

Great percentage, but even so, it all caught up with him a few years ago. Hopper underwent a couple years of therapy, had his name removed from the rescue-call list.

"It wasn't one incident," he says, "it was a culmination. I tried to stuff 'em all in this bag. The bag gets so big, it bursts."

Hopper is a bear of a guy with a bushy mustache and a sensitive side. When he noticed that waterfront joggers have a ritual of touching the fence at the dead-end of the sidewalk next to Fort Point, he had the bridge's sign painter make a sign with two handprints on it, and another sign with two dog paws, because one woman had her dog touch the fence.

So losses haunt him. Once Ken and two other ironworkers were clinging to one arm of a man hanging over the rail. The man grabbed another piece of bridge with his other arm, wrenched free and swung off another beam and into the world's most popular suicide pit.

Another time, Hopper arrived at a rescue just in time to see a man fling his 2-year-old daughter off the bridge, then jump off himself.

It eats at Hopper when a talked-down suicide is taken into custody and then quickly released with little or no psychiatric observation. Hopper talked an 18-year-old City College student off the bridge, and she was taken away by police.

The next morning, while a press conference was being held at City Hall to announce a new bridge suicide-prevention program, the teenager walked back onto the bridge and jumped.

On occasion, the family of a jumper will later seek out the ironworkers involved in the attempted rescue. What happened? What were my son's last words?

"You try to help them get some peace of mind," Hopper says.

But what about peace of mind for the ironworkers? They almost never get info on what happens to the people they rescue.

Hopper says that's a sore spot. No follow-up, no closure. You help save a life, you become involved in that life, you know?

"Once in a great while," Hopper says, "one of the guys will get a letter or note from someone they talked down. I've known that to happen only two or three times. When a guy gets a letter like that, it's a treasure; it's like gold."

Mostly, the ironworkers don't talk or philosophize or complain about this aspect of their job. They don't talk feelings. They're tough guys.

As soon as Hopper completed his therapy, as soon as he felt like he had a handle, he put his name back on the call list for rescues.