Left caption: STEEL WORK — Construction men anchor down steel girders that will form the entrance to one end of a diversion tunnel at the Castaic Dam. After the tunnel is dug, the steel will be covered with concrete. Right caption: INSPECTION TOUR — Project manager John Coyle looks over the progress of work on the Castaic Dam, then, right, has a truck-to-truck conference with one of his superintendents. (Click to enlarge.)

Castaic Dam Site Explodes Into Action

Drill. Blast. Dig, then drill again.

Six times a day explosions ring out from the site of the future Castaic Dam near the small town of Castaic. And with each explosion, a mammoth diversion tunnel — the first major step in building the dam — moves closer to completion.

The finished dam will be a major project of the statewide Feather River Project, impounding water for the entire Los Angeles basin.

Project manager John Coyle has 75 of his men hustling around the construction area. They're digging, planning, measuring and sculpting the earth to fit the future dam.

But the heart of the activity is inside the tunnel on the downstream side. A score of men there man seven drills on a two-decked machine called a "drill jumbo."

They bore holes into the earth, fill them with powder and blast. Then, ignoring the screaming drills, the choking dust and near blackness of the tunnel, they go back in and drill some more.

The physical work is being done in the tunnel, but the managing work of the project takes place in the project office, a neatly furnished trailer sitting near a stand of trees. This is where Coyle keeps track of his $8.5 million project and makes his reports to the Omaha, Neb., headquarters of the construction firm he works for.

Pacific Telephone has installed six telephone lines for Coyle's office, giving him service from the Newhall central office, some 10 miles away.

What does Coyle use the phones for?

"You name it," he says. "We usually have most of the lines busy 10 hours a day. Our calls go all the way from ordering supplies to talking to the general office."

At the upstream end of what will be a 3,600-foot diversion tunnel ranging in diameter from 19 to 27 feet, men lay steel for a reinforced portal. Drilling will begin there soon.

With the two drilling teams starting more than a half-mile apart, how does Coyle expect them to meet? "I've got some engineers who are supposed to know what they're doing," he says.

Coyle's tunnel, when finished in Fall, 1967, will divert water around the construction site of the dam. The dam itself will be finished in 1970. It will be 335 feet high and will hold the largest reservoir in Southern California.