Photo: Joe Woolhead

During an eventful year on the World Trade Center site, crews found glacial formation at the site of Tower Four during excavation.

Photo: Silverstein Properties

Crews place reinforcing steel at Tower Four, which will also be known as 150 Greenwich St.

“The public side of the World Trade Center site is clearly moving forward,” says Port Authority Executive Director Chris Ward in an e-mail. “Last year’s assessment was an important turning point, but much more work lies ahead. We must continue pushing aggressively until every project is complete.”

Port Authority spokesman Steve Coleman says in another e-mail that One World Trade Center, the National September 11 Memorial and Museum, and the Transportation Hub are on schedule. Current target dates, according to the Lower Manhattan Construction Command Center, which had no one available to comment about progress at the site, are 2013 for Tower One; Sept. 11, 2011, for the memorial plaza and mid-2013 for the rest of the memorial; and mid-2014 for the transportation hub.

New York Construction reported in 2006 that the original completion dates were 2011 for Tower One; Sept. 11, 2009, for the memorial; and the end of 2009 for the transportation hub.

Candace McAdams, another Port Authority spokesperson, says the Port Authority reassessed the construction program last year and put together new timelines and a new budget in October. The projects are meeting those new schedules, McAdams says. Nearly 1,000 people are working onsite at the Port Authority’s three projects. In mid-June, the Port Authority completed the sale of $750 million in consolidated bonds allocated for capital expenditures in connection with One World Trade Center, the retail components of the World Trade Center site and other World Trade Center sitewide infrastructure.

On the private side, Scott Thompson, project manager for Silverstein, says Tishman Construction Corp. of New York is making good progress at World Trade Center Tower Four, also known as 150 Greenwich St., for World Trade Properties, an affiliate of Silverstein Properties of New York.

The Port Authority, however, remains in a standoff with developer Silverstein Properties over the developer’s request for the Port Authority to guarantee as much as $3.2 billion in construction loans. In early July, Silverstein Properties provided the Port Authority with a “Notice of Dispute” letter, reflecting the Port Authority’s inability to meet its rebuilding obligations at the World Trade Center and the major financial and logistical consequences of these failures on the Silverstein organization’s ability to rebuild.

In a written statement, Silverstein Properties says the notice triggers a 10 business-day period for the parties to meet to try to resolve their differences. If they fail to achieve an agreement, either party can ask to resolve the dispute through binding arbitration.

“Today’s action is designed to inject a renewed sense of urgency to these discussions and, should those discussions fail, to take the matter to an impartial panel of experts as early as this month,” says developer Larry A. Silverstein in the written statement. “One way or another, we must take any and all steps necessary to resolve, once and for all, the disputes that have arisen as a result of the Port Authority’s continued and admitted delays.”

The Port Authority issued a written statement in response, from Ward, saying, “It’s unfortunate SPI is walking away from the negotiating table simply because the public has been unwilling to sacrifice critical transportation projects to subsidize private speculative office space. The Port Authority is meeting all of its obligations, and we look forward to a quick arbitration decision should Mr. Silverstein continue down this legal path.”

World Trade Center Tower Four Tishman broke ground on the $2-billion, 64-story Tower Four, designed by Maki and Associates of Japan, in February 2008. It will contain three levels of retail space and about 2.3 million sq ft of office space. The Port Authority has agreed to lease a third of it.

During excavation, crews found a glacial fill, with smooth rocks and boulders that required removal and filling with a flowable-fill concrete.

“It’s a lightweight concrete that will find every crevice,” Thompson says.