By Erin Sherbert
By Erin Sherbert
By Leif Haven
By Erin Sherbert
By Chris Roberts
By Kate Conger
By Brian Rinker
By Rachel Swan
But frogs are the least of Richard Nutt's worries right now. An engineer, his top concern is making sure that the two sides of the bridge meet in the middle — a fundamental aspect of bridge building. The frogs, though, have complicated matters.
Generally in bridge-building, especially with bridges that curve like this one, workers erect a temporary framework below where the bridge will span. The workers build on top of that scaffolding, then remove it once the project is complete.
That framework between the bridge's two pillars, though, would have sat right on top of the red-legged frog pond.
Nutt's strategy, then, is to build directly outward from each pillar, as if expanding the horizontal bar on a capital "T," a method called the "segmental technique." But the two spans do not automatically meet in the middle: Without supportive framework, the further out each span goes, the more it sags from the added weight. Each new segment added to the span must account for the sag created by the previous one, like an archer aiming just above the target in order to hit the bullseye.
So there is Nutt, sitting in his Sacramento office, looking at a bunch of numbers on a computer program. The fate of the Devil's Slide bridge rests on this program and the man using it. Nutt's competency, you don't have to worry about. But the program, well, just five or six years ago it wouldn't have been able to handle the construction of a curved bridge. Because curved bridges flex downward and also twist sideways, which is an insurmountable complication for a program that calculates in only two dimensions. But the computer has since been taught new tricks, including working in three dimensions. Technology has turned a corner, becoming so efficient that man can afford the luxury of developing a consciousness of nature — in this case the luxury of frogs, treating them not as another obstacle, but as neighbors on the mountain. The frogs caught man at the right time.
Nutt inputs various measurements into the computer and the computer spits out directives for the machines erecting the next segment. The spans extend as the concrete dries, both sides reaching toward one another, leaving the land underneath untouched.
The long days aren't so bad — there's a crisp breeze and ocean view. The pay is meager, but enough so the children don't starve. And after years on the job, the weight of the hammer becomes familiar. No, the hardest part of working on this railroad is the rebuilding. The glory and most of the money go to the bosses, the men at the top of the Ocean Shore Railroad Company. But there's a pride in looking back after hours of pounding spikes and seeing those iron rails stretch back. Seeing the progress.
So it feels like a punch to the kidney, clocking in this morning only to find out that an overnight rockslide has torn apart more than 200 yards of track. There is at least half a day's worth of debris to clear. And after that, the hammer will pound a spike where a spike had already been pounded.
This railroad was supposed to be a marvel, 1,500 volts powering trains down two tracks along the coast, barreling through the mountain at the San Pedro Point tunnel. Then the earthquake hit. And the investors figured their money was better off in some crumbled hotel or restaurant or civic project than in a railroad that keeps breaking. Rebuilding the greatest city in the West offered both moral pleasure and sure profits. The railroad will be single-track now, and the trains will be powered by steam.
But that's all still a long way off. The hammer feels heavier today.
The mountain is under siege. For months, the workers have blasted through it with dynamite and burrowed through it with excavators. They've set up camp, spraying the tunnel walls with concrete and installing bulky ventilation systems. The men are convinced they've figured out the mountain.
But the mountain has unleashed its array of defenses. It flooded the men's equipment with water. It released ungodly tectonic pressures to squeeze the tunnel so that the men had to retreat and suspend their attack for more than a month, until the mountain had no more force to exert. And it ambushed the men with unexpected rock formations.
Today, for instance, is supposed to be a drill-and-blast day. But the rock face was too soft and holes won't stay open. More alarming, blasting into weak rock risks fracturing the surrounding rock, potentially causing the newly opened tunnel face to collapse in on itself. So the huge drilling machine must slowly reverse its way out of the tunnel. Time burns. The mountain holds its ground.
This isn't supposed to happen. There was a plan. Geologists like Doug Hamilton extracted long, tubular rock samples from two dozen or so strategic intervals in the tunnel's path, effectively mapping out the geologic conditions of the mountain. Engineers like Dan Zerga used that data to design support systems based on the varying rock formations expected, with separate specifications for the strongest rock, Category 1, up to the weakest rock, Category 5.