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Assault on Devil's Slide: A 150-Year Tale of Man Versus Mountain 

Wednesday, May 1 2013
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Page 3 of 5

He pitches the idea. Soft-spoken but with an air of confidence, Hamilton explains that a tunnel would be a permanent fix to the road, that its environmental impact would be negligible, and that its cost would be comparable to that of the bypass. Lempert is hooked. So is Barrales. They hadn't heard of this possibility before. Caltrans hadn't built a tunnel since 1964. Back in the 1970s, a Caltrans geologist had floated the idea of a tunnel for Devil's Slide. But the department, full-steam ahead with the bypass, quickly shot down the proposal after preliminary evaluations, claiming that it would cost too much. The idea never resurfaced.

Until now. Lempert and Barralles ask around the room for reasons why the tunnel wouldn't work. But they find no serious dissent. Lempert feels a surge of relief and excitement. He doesn't yet know how it will happen. Doesn't yet know of the political wrangling ahead, the grassroots campaign and the ballot measure and the lobbying for federal funding.

Lempert's mind is calm as he strolls out of the conference room. All he can think is that he's found a solution to the Devil's Slide problem. Whatever obstacles lay ahead, that's for tomorrow.


The next day should be easier. By then the road should level and begin to decline. The horses are tired from the steep climb. This part is the hardest, they say. It's Day One on the Half Moon Bay-Colma Road, which the newspapers called "as treacherous a piece of road as can be found. Death stalks in front and lurks behind in every foot of the climb to the summit."

The summit must be near, but it's hard to say with all the fog. Not that the thick white haze is unwelcome. The wagon teeters with every bump over the rocky terrain, and it's probably best that the drop beyond the cliff stays hidden. For sanity's sake. The lifeless wagon up ahead, though, has come into view. It sits on the side of the trail, abandoned and with a busted wheel. What happened to those folks? But there is no time to linger and wonder. It is perhaps another full day's travel to San Francisco.

They've called that place the Emporium of the Pacific, full of wonder and jobs and brothels. The depression of the Reconstruction has passed, and this city, as far from that Eastern carnage as you can get, seems an ideal place to build a life.

So there is much ground to cover before nightfall, when the mountain turns into a cold, howling Golgotha. In those hours, the wilderness is in control. And there is nothing to do but lay prostrate at its feet, praying for mercy.


Blame the frogs. There wasn't even supposed to be a bridge here. The original plan was that a normal road would lead into the tunnel's north portal, which meant filling in this corner of the Shamrock Ranch with concrete. Early environmental reports, though, noted the presence of endangered red-legged frogs. So the plans changed. Now there's a thousand-foot bridge going up and an official protocol for what to do if any of the little guys wander onto the construction site. Find a bucket — one of the specially designated frog buckets — drop it over the frog, then phone whichever of Caltrans' three official biologists is on call that day. A rescue team mobilizes and transports the animal back to its habitat with a stern warning.

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.


About The Author

Albert Samaha

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