From Terrill Yarde's 200-foot-high perch in the crane he operates, the magnitude of the Big Dig begins to take shape.
From there, he sees the hundreds of hard hats toiling inside the approaches that lead into the Third Harbor Tunnel in South Boston and East Boston.
"I like it up here. It is one of the few jobs where you get the full picture of just how big this thing is," says Yarde, 43, of Dorchester.
Yarde and dozens of other crane operators are moving controls that lift billboard-sized wooden frames and car-sized bundles of steel reinforcing rods into place as scores of concrete mixers wait, ready to pour into the forms that will shape this tunnel, scheduled to be finshed next year.
In the end, the artery-tunnel project will use 4 million cubic yards of concrete, enough to fill Foxboro Stadium 12 times.
"It blows you away when you think about it. So I try not to think about it," says Yarde.
Currently there are about 1,500 jobs, but by the time the project is fully under way there will be some 5,000 construction jobs, representing steel workers, tunnel workers, Teamsters, and scores of other trade unions across the city, the state and the country.
An additional 10,000 white-collar jobs will also be created, from accountants to design engineers to office secretaries. A program aimed at helping young people from inner-city neighborhoods learn skills -- from welding to accounting -- is also under way with 100 positions filled so far and more promised for the future.
"This is more than just a transportation project," says Project Director Peter Zuk. "It is an infusion for the economy. These are people who buy groceries and pay rent and buy houses and shop in malls. The impact on the economy moves out in waves."
Climb down inside the immersed tubes that form the tunnel beneath Boston Harbor, and the energy and activity of the project come alive. Three hundred men and women are working on finishing the tiling along the walls.
In the end, some 1.6 million pieces of tile will be tapped into place. Enough to cover 4,600 bathrooms.
Cruising through the tunnel on a forklift is the deputy project director, William Flynn. Flynn, an Army general during the Persian Gulf War, moves among the work crews like he's surveying the troops. In the tunnel and in his office, he's known simply as "The General." He wears a hard hat instead of a helmet.
"The stakes are higher in a war, of course," said Flynn. "But the scale and the scope and the intricacies of planning are similar. . . . It is almost impossible to comprehend the size of it."
Flynn was in the tunnel with construction manager Joe Allegro, who said, ''This is an exciting day, you can see we are putting the first ceiling panels in."
But of course, with every breakthrough are the attendant headaches. It turns out that the first 1,000 of the total 20,000 ceiling panels were shipped improperly. The metal seal is bent on some and the concrete setting inside is cracked on others. A total of 950 are rendered useless or "red tagged" by quality control. Total cost for today's headache: $1 million.
Still, Flynn smiles and talks with the workers down in the tunnel, including Rachel Sifontis of Laborers' Union Local 22. Sifontis, 48, was working alongside her son, Ricardo, 27. Residents of Cambridge, they emigrated from Trinidad and are a 1990s equivalent of a traditional, generational pattern of parent and child landing construction jobs with the union.
"I'm proud of the work," says Rachel. "But you know what I think about when I'm putting up tile? I think about driving through this tunnel with the next generation, my grandchildren, and we will be able to say that we had two generations build it."
There's Pat Sheridan, a tunnel worker -- or sandhog, as they call themselves -- operating a forklift and talking about how he was the first one to break through the immersed tube tunnel. Sheridan was there scrubbing the barnacles and the seaweed off the inside of the dark tunnels.
"There were lobsters and fish flopping around in there in this black muck," said Sheridan. "The smell was unbelievable. I almost lost my lunch."
Outside, working to build the forms in which concrete is poured, was Billy Greene, 43, a father of three who lives in Hyde Park and works for Carpenters Union Local 33. As he puts it, "This is a once-in-a-lifetime job. I hope this is where I'll be right up to retirement."