As an audience of more than one billion watched China gymnastics legend Li Ning "space-walk" to light the cauldron of the Beijing Olympic Games, a team of 650 construction workers could not experience the exciting moment.

The workers were at Beijing's National Stadium, better known as the Bird's Nest for its unique steel structure, the center stage for last Friday's long-anticipated opening ceremony.

They were not watching the spectacular performances. They were right in the pit under the main stage.

The workers were on hand to quickly dismantle the facilities used for the magnificent show. Only 84 hours was allotted for them to complete the changeover to the stadium for the track and field competitions, soccer match and eventually, the closing ceremony.

Officials from the International Track and Field Federation and the Beijing Organizing Committee of the Olympic Games (BOCOG) would come punctually at 12 o'clock on Tuesday noon to see a fully-functional stadium for the competitions.

It would normally take at least two weeks to complete the huge changeover. This involved removing all the fantastic stage props from the opening performance, such as the big "scroll," and installing equipment for the closing ceremony in the pit, and smoothing the field for the athletics.

"Every detail has been carefully planned to get the 'mission impossible' done," said Yan Cheng, deputy head of the logistics team for the opening and closing ceremonies.

Yan held a schedule detailing 54 procedures for the stadium's transformation, a result of consultation with the city's transport department, maintenance workers and security forces at the venue.

"The odd and even traffic restriction plan, frequent traffic controls in the region near the site and limited entrances, only four at the stadium, have added to the difficulty," he said.

About 11,000 tonnes of cargo needed to be loaded and unloaded in the 84 hours, including more than 4,600 tonnes of turf.

Only 24 hours were scheduled for laying the turf, while the same amount of work took 66 hours at the 2004 Athens Games.

At 3:30 p.m. Sunday, three 200-tonne cranes were working simultaneously at the stadium center, trying to lift huge equipment into the pit.

Yan said they had even arranged mobile gas-filling vehicles into the stadium to save trips to the gas station.

When heavy rain fell late on Sunday afternoon, workers were forced to don raincoats but the inclement weather couldn't hinder the progress.

On Monday morning, all the equipment for the closing ceremony had been installed and fine tuned. Large vehicles such as cranes had left the facility and half of the lawn was laid; the other half to be completed at midnight. In addition, the layout for the lanes for the track competitions were half finished.

"We are confident of getting the stadium ready for Wednesday noon, according to the current progress," said Yu Jianping, chief engineering officer of the opening and closing ceremonies.

He added more than 4,000 engineers, workers and soldiers had participated in the changeover.

The athletics competitions at the stadium are to start on Friday, while the men's soccer final and the Games closing ceremony will be staged later.

(Xinhua News Agency August 11, 2008)