In a project distinguished by superlatives -- one of the largest drawbridges in the world, among the most expensive public works projects in the country -- yesterday brought another historic feat for the Wilson Bridge project: the heaviest lift.

Construction workers hoisted 466 tons of steel 76 feet into the air, connecting part of the drawbridge to its supporting piers.

"This is the moment we've been waiting for," said Frank Petsko, a general foreman with Iron Workers Local Union 402 of West Palm Beach, Fla., who took a break to watch.

The 270-foot-long draw span is the most technically challenging part of the bridge project as well as the costliest: $186 million.

While many of the hundreds of workers climbing all over the V-shaped piers took notice of the nearly five-hour lift, it had no effect on the traffic whizzing by on the old bridge.

The work that drivers probably will notice this weekend involves a part of the construction project that will reduce traffic on the Capital Beltway's inner loop to one lane at the bridge.

The work, which will shift a part of the inner loop on the Alexandria side of the bridge, was scheduled to started at 8 p.m. yesterday and finish by 5 a.m. Monday.

Project managers are warning drivers to avoid the bridge this weekend or face extensive delays, although a similar closure last month did not lead to the huge traffic jams officials had feared.

The draw span is only a small part of the 7.5-mile-long, $2.43 billion bridge project, which also involves extensive changes to the highway approaches and interchanges.

Jim Ruddell, overall construction manager for the project, said workers have been preparing for the lift of the draw span for six months.

The 155-foot-long steel section is made up of two pieces that form part of the drawbridge. It was delivered on a yellow barge from Florida, where it had been built outside Jacksonville by a subcontractor, PDM LLC. The same company built the drawbridge span for the old bridge 40 years ago.

Instead of lifting the two pieces separately with floating cranes, and connecting them in the air, both sides were raised together.

Four hydraulic jacks, called strand jacks, were attached to each of the corners with steel cables.

The lift began at low tide, about 9:30 a.m., when the Potomac River was calm. The Coast Guard redirected boats to keep the water from getting choppy.

The jacks clamped into the steel cables and pulled at a rate of 17 inches every three to five minutes. As the steel moved up, the taut cable got shorter, and the pigtail of slack cable grew longer.

The draw span moved slowly. To watch it was like watching the sun take all morning to rise to the top of the sky.

From a platform 78 feet in the air, J. Daniel Bell, project manager for the drawbridge portion of the project, supervised the lift.

"So far, so good," he said about 11:30 a.m.

He explained that every few pulls, the 11 men and one woman who monitored the hydraulic jacks marked the progress of the steel pieces with tape measures and with the help of surveyors to ensure that no corner got more than its share of weight.

Then they readjusted the cables accordingly.

Once the span finally was in place, about 2 p.m., the three-day process of bolting it to the connecting steel with more than 3,000 high-strength bolts could begin.

The enormous structure eventually will pivot up with the help of a steel box filled with concrete to balance it. It will take only a relatively small motor -- about 150 horsepower -- to move it into the air.

The new bridge will open about 60 times a year instead of the 250 times that the old bridge opens because, at 78 feet in the air rather than 50, more boats will be able to pass beneath it.

The barge already is headed back to Florida, where it will pick up another piece of the drawbridge, and the whole routine will be repeated in a few months, keeping officials on track to open the first span of the new Wilson Bridge in mid-2006.

Ultimately, there will be two drawbridges on the outer loop and two on the inner loop. The whole project is scheduled to be finished in 2011.

From the vantage point that cars will someday have at the top of the bridge, tree tops are visible along the coast of Virginia, as are V-shaped piers below in various stages of undress -- some with rebar jutting out, but more and more are covered in concrete.

Up top, a worker was scrubbing the concrete on the new observation deck, and with the draw span moving into place nearby, it was starting to look like a bridge.

Construction workers took nearly five hours to hoist 466 tons of steel 76 feet into the air, connecting part of the drawbridge to its supporting piers. Construction of the new Woodrow Wilson Bridge stretches high into the sky. The 270-foot-long draw span is the most technically challenging part of the bridge project, as well as the costliest: $186 million. The entire project is expected to be done in 2011. The draw span is only a small part of the sweeping, 7.5-mile, $2.43 billion bridge project. More work this weekend is expected to cause traffic delays.