Glass Eliminated from One WTC Podium Wall
May 12, 2011

The glass portion of the podium wall of One World Trade Center in New York has been eliminated from the tower's design, the New York Times has confirmed.

Originally, architect Skidmore, Owings and Merrill (SOM) in New York had specified that the lower 20 stories of the tower would feature an ultra-clear glass unique from the remainder of the 104-story tower (the top of the tower currently is being installed).

The high-profile project has undergone changes since its initial conception. In October 2010 it was announced that PPG Industries in Pittsburgh would manufacture the glass for the tower's podium wall, after having been told in early 2009 that the contract was instead going to a Chinese glass company. Zetian Systems Inc. in Las Vegas was supplying the Starphire glass to fabricator Sanxin Glass in China, and bringing it back to the United States to be installed by Solera/DCM in New York (Representatives of Solera/DCM declined to comment for this article).

A statement Zetian issued to USGNN.com™ in October 2010 noted, "It is very common that the selection of materials and finishes for a very high profile project is extended over a relatively long time period."

Zetian president Greg Olin told USGNN.com™/UGSlass Magazine in March that the decision to specify PPG's glass was made by the architect. "We are suppliers; when we put the options on the table and the architect says 'I want that one,' I don't ask why," he said. "There's a world of difference in the way that glass looks. The combination was just perfect. Once [the architect] saw that it was available, and there was some inventory available immediately to do the trials that we needed in order to keep the contract schedule, it became a no-brainer." (Look for the May USGlass for an in-depth profile of this supplier.)

Representatives of SOM would not return calls from USGNN.com™ to comment on the reason for the design change. However, the Times reported that as of the trials at Sanxin Glass in March, the "glass panels tended to bow after they were cut and tempered, which interfered with the lamination process."

Talking with USGNN.com™ this morning, Olin commented on the New York Times' report: "They [the Times] managed to identify two key points: the scale and the breakage effect. Prismatic glass can be tempered and laminated successfully into smaller lite sizes than designed, but when it breaks, it acts differently than tempered flat glass - no matter what size. This is the key to the change. It has nothing to do with where it is produced. The laws of physics apply universally."

As of March 11, representatives of PPG had told USGNN.com™ they were not aware the design had been scrapped.

Neither the Port Authority of New Jersey and New York nor Tishman Construction, the general contractor on the project, would return calls from USGNN.com™ to comment.

Stay tuned to USGNN.com™ for further updates on this story as they emerge.

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