WASHINGTON, Nov. 18  -- With completion of scaffolding surrounding the Capitol Dome, the restoration project of the 150- year-old American icon in Washington D.C., the U.S. national capital, has entered a new phase, officials said Tuesday.

"I'm pleased to announce this morning that the scaffold you see behind me is complete," Stephen Ayers, Architect of the Capitol, told reporters from the roof of the Capitol. "This is a significant milestone for us in our dome restoration project."

Construction workers, after using pipes totaling 84 kilometers in length and weighing some 550 metric tons, finished the scaffolding that would allow them access to the cast-iron dome for starting repairs on more than 1,300 cracks there. The restoration work includes removal of old paint, repairs to the cast iron and stone, and repainting.

"This is incredibly important," Senator John Hoeven said. "The dome is a symbol not just for our country, but a symbol of freedom and liberty for the world."

On Tuesday, construction workers for the restoration project also demonstrated some of the tools and techniques they use to repair the dome, including blasting, priming, drilling, as well as installing pins and locks.

Ayers told reporters that the last restoration of the dome was conducted more than 50 years ago, and with today's technology he expected the current renovation would be good for 75 to 100 years.

Joe Abriatis, construction manager of the restoration project, said the 60-million-dollar undertaking is on budget and will be finished next fall.

When the next president is sworn in, Americans can see their Capitol and will be "confident that, just like this great nation, it's here for the long term," Hoeven said.

The U.S. Capitol in Washington is a world-famous tourist attraction, hosting more than 1 million visitors every year.