Demolition, Abridged Version

It’s a sprint against the clock, a race to make 4 million pounds of concrete and 100 tons of steel disappear.

Caltrans allows freeways to close from midnight to 5 a.m. only. That leaves five slim hours for construction and demolition and without the help of explosives--forbidden on the site--it’s not nearly enough time to tear down a bridge, clear the rubble and sweep dust from the pavement in time for morning commuters.

So the Collins Avenue bridge demolition over the Costa Mesa Freeway in Orange unfolded over two nights this week--Tuesday into Wednesday morning, and Wednesday night until 5 a.m. today. The rigid deadline dictated the schedule and fueled the adrenaline rush for the seven-man Penhall Co. of Anaheim crew, which this week made the Collins Avenue bridge crumble.

The Penhall operators, with more than 75 years of combined experience, used monster machines called excavators that employed 8,000 pounds of hydraulic force to systematically punch and paw at the concrete and steel bars of the bridge deck and columns.

“The challenge is just getting the freeway open at 5,” said Milt Muller, the gruff superintendent for Penhall, a veteran bridge wrecker who directed this week’s demolition project.

The 37-year-old Collins bridge was condemned to make way for the $118-million widening of the Costa Mesa Freeway through Orange. The old structure was 170 feet long. Its replacement, which won’t be finished until the summer of 2001, needs to be 23 feet longer, so the entire Collins bridge had to come down--an event that Caltrans carefully planned for months, and delayed for several weeks until the nearby Walnut Avenue bridge reopened.

“We’ve been planning this for eight months now,” said Robert Zordani, a Caltrans bridge engineer supervising Wednesday’s job. “A lot of people will be affected by this on a very massive scale.”

An hour before authorities blocked traffic on the freeway, Muller was already wearing a tight scowl, barking orders to his crew, who used torches to remove the bridge railings. Muller was already sweating the late arrival of one of the excavators. He knew that one small slip-up could push the 5 a.m. deadline.

Sure enough, on this night, the late-arriving equipment would break down an hour into the job.

“Equipment breaks down, a million different things can go wrong,” said John Payne, an engineer in charge of safety for the Collins Bridge project. “That window is just so small.”

Still, Caltrans won’t bend.

“If they cannot complete the total amount, we still have to shut it down and get the freeway cleaned up,” said Ching Chao, Caltrans senior bridge engineer, who worked on the project. “You cannot just leave things hanging out there. And you can’t leave a mess on the freeway. It takes at least a half-hour for the cleanup work, so they really only have four hours of productive work.”

Muller made the most of it Wednesday, meeting the expectations of Payne and the Caltrans engineers who declared Muller one of the best. Galloping up and down the bridge embankment, Muller shouted orders that were audible above the deafening staccato, a Howitzer-like rat-tat-tat-tat of the excavators as they repeatedly slammed into the bridge. Before long, the machines had exposed a rib cage, a web of rebar reinforcements, and guts of concrete.

At 12:55 a.m., a few minutes after the first girder fell into a lifeless heap, Muller shouted for his front-end loader driver to begin scooping up the rubble.

“C’mon, c’mon,” Muller shouted, wildly winding his left arm, resembling a third base coach waving in a base runner during the World Series.

The Collins Avenue bridge was an easy one to destroy, said Payne and Muller. The bridge design was simple, typical of those erected during the freeway-building frenzy of the early 1960s. It had nine T-shaped girders supported by nine columns. It was nothing like the demolitions of double-decked bridges, such as the Cypress structure in Oakland that collapsed 11 years ago.

By 3 a.m., the bridge deck was history and the first of six columns toppled. Payne said Muller’s crew was a few minutes ahead of schedule. Later, members of Muller’s crew would say they thought they were running 30 minutes behind schedule.

“Get ready for the grand finale,” Boris Irahola, a Caltrans structures representative for the Costa Mesa Freeway, said just before the last column went down at 3:55 a.m. At that hour, there was still plenty of time for the loaders to push the tangled steel rebars to the side, and load the last chunks of broken concrete that would later be pounded down for recycling.

Irahola had spent weeks poring over the details of the demolition plan, but he was still amazed at the speed that a bridge could be demolished.

“It takes up to six months to build one of these things and it takes just two nights to tear it down. Less than 10 hours,” Irahola said. “This just shows how much destructive power human beings have, rather than constructive power--the construction to rebuild it.”

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A Short Span

Demolition crews worked feverishly for two consecutive nights to tear down the Collins Avenue bridge over the Costa Mesa Freeway in Orange. Here’s how the carefully choreographed project was completed:

1. Midnight-1 A.M.: Excavator punches holes in cement

2. 1-3 A.M.: Knock down girders, remove rebar

3. 2-5 A.M.: Topple bridge supports, haul off debris, remove dirt from road

Graphics reporting by BRADY MacDONALD / Los Angeles Times