RALEIGH — They call it The Hole -- a hidden, 30-foot curiosity. While Raleigh slept, a team of 30 workers dug a tunnel under McDowell Street, making one of downtown's busiest streets into a bridge without anyone's noticing.
You can drive right over it, just south of Poole's Diner, and not realize that only air floats beneath.
But one story down, giant trucks are passing through a hole 30 feet tall and 60 feet wide, supplying Raleigh's new $215 million convention center with 300 tons of steel a week.
"It's the secret tunnel," said David Wiest, construction manager with Barnhill Contracting. "It's Raleigh's version of the Big Dig."
Minus the screw-ups so common to its Boston namesake.
For the past year, Raleigh's convention center has amounted to little more than a deep mud pit.
But in the past few months, steel and concrete have started to rise out of the hole below McDowell Street, the first signs of the brick, stone and glass center to be finished in 2008.
Digging out all that dirt --330,000 cubic yards of it -- was a hassle made necessary by the center's design. Half of the 500,000-square foot building sits below street level, which keeps what is essentially a huge box from jutting another 40 feet into the skyline.
Working in the pit and hauling all the machinery through the tunnel kept workers from gumming up McDowell Street -- a state road that crews were not allowed to close.
They shifted the traffic over one lane, dug underneath it, then shifted it back to dig the tunnel's other half. The tunnel has been open for the past few months.
Workers get to it off Lenoir Street, through the mostly vacant lot that sits just to the convention center's west side.
When the center opens, tractor-trailers can use the same tunnel to move bulky loads into boat and car shows.
"All this big truck traffic down there," said John Muter, Barnhill's vice president, "and you'll never see it."
For now, it is all backhoes and front-end loaders coming through, not to mention 500 cubic yards of concrete every week.
Construction was dicey for a while as Progress Energy paid to remove contaminated soil from the old gas works that operated there until roughly World War I.
That empty lot on Lenoir Street is slated for "festival space" right now but would be handy if the center expands.
So far, the crews have gone more than a year without an accident more serious than a cut finger.
Drive over McDowell Street and they will be right underneath, in The Hole.