Workers have begun to install membrane structures of the National Aquatics Center, known as " Water Cube", and the work is expected to be completed at the end of the year.

Workers install plastic membranes to make up bubbles in the structure of the National Swimming Center for the 2008 Olympic Games in Beijing September 21, 2006. Known as the 'Water Cube', the futuristic swimming complex is made up of 4000 air bubbles, which are intended to make it an energy efficient insulated greenhouse. [Reuters]

"When the membrane structures are all in place, the 'Water Cube' will look almost no difference from the computerized design, " said Kang Wei, general manager of the showpiece venue for the 2008 Olympic Games.

The membranes comprise over 3,000 pneumatic cushions which are restrained in aluminum extrusions and supported by lightweight structures. The cushions are inflated with low-pressure air to provide insulation and resist wind loads.

The cushions are manufactured from multiple layers of a modified co-polymer called ethylene-tetra-fluoro-ethylene, or ETFE.

The National Aquatics Center comprises over 100,000 square meters of ETFE foils, making this the single largest ETFE structure in the world to date.

The center will host swimming, diving, water polo and synchronized swimming competitions for the 2008 Olympic Games.

The entire project, which was started December 24, 2003, is scheduled for completion in October 2007.