The 500-ton cylindrical drill that will carve its way from the North Shore to the new Gateway Station, Downtown, and back began its journey slowly yesterday.

The massive machine, strapped into a red gantry crane, was lifted up, then carried forward as the crane inched its way along a red steel track into the starting pit opposite PNC Park.

Construction workers snapped photos with cameras and cell phones, but to uninitiated observers, it was almost impossible to tell it was moving.

The blue and white drill -- 23 feet in diameter and looking like something out of a Jules Verne novel -- will burrow a pair of 2,400-foot tunnels under the Allegheny River for an extension of the Port Authority's Light Rail Transit system, scheduled to be completed in 2011.

The $435 million project, which is getting 80 percent of its funding from the federal government, will link Downtown to two new stations on the North Side -- one below ground by PNC Park and one above ground next to Heinz Field.

After workers carefully guide the $10 million marvel into place and assemble two trailing sections that will pump out debris, they will bore a 50-foot starter hole next month to test the machine, said Winston Simmonds, rail operations/engineering manager for the Port Authority.

Serious drilling should begin by late January.

At a rate of 20 to 30 feet per day, the drill will take several months to reach its destination underneath Stanwix Street, Mr. Simmonds said.

After any necessary repairs are made and workers turn the drill around, it will bore a parallel tunnel 20 feet below the river bed, returning to its origin.

"It's the latest technology in tunnel-boring," Mr. Simmonds said of the drill, manufactured by German company Herrenknecht AG, which has built drilling machines all over the world for transit and other projects.

The drill's cutting head, which is flat, not pointed as one might think, is operated by laser-guided hydraulic pistons. The drill and accompanying apparatus will be manned to make sure it's on course as it gradually churns through the earth.

Slurry and other debris slide through holes on the front of the drill, are chopped up into pieces no larger than 3 inches in diameter and pumped back to a plant at the original hole to be recycled or disposed of.

At the drill's receiving pit, Stanwix Street will be closed between Penn and Liberty avenues -- next to Gateway Station -- for 17 months starting early next year.

The Port Authority projects the subway extension will have 4.2 million riders per year.

But that is years away, as the snail's pace of the drill yesterday demonstrated.

After outlining the project for a group of reporters, Mr. Simmonds stepped back for a second, glanced up at the drill, smiled and said:

"A lot of this is, 'Hurry up and wait.' "