DEP Invoice or Financial Record, September 30, 2001

NYC 9/11 Public Portal Document

I Keeping 'bathtub’ dry Expertsfight to secure WTC'sfoundation By ROBERT INGRASSIA DAILY NEWS STAFF WRITER

Engineers plan to 16 ACRES OF TROUBLE shore up portions of a huge concrete basin

Si under the collapsed twin When the 110-story towers of towers to make sure it World Trade Center were under doesn’t give way and construction in the late 1960s, Engineers plan a 16-acre basin was laid deep

Bi “H': flood the PATH train sys- to fortify portions In the Earth to protect the of the bathtub tern. excavation site and surround­ The 60-foot-deep cavern, with cables and * known as the “bathtub,” housed ing streets and buildings. braces to keep the foundation and basement lev- Some basement floors support­ them from k els of the World Trade Center, ing the 60-foot-deep basin — collapsing p keeping out water from the Hud­ the socalled bathtub — col­ son River. as crews b When the towers crumbled, lapsed when the towers remove debris. I some of the basement floors sup- crumbled, leaving only rubble ' ' f porting the 3-foot-thick basin holding up parts of it. walls collapsed. Portions of the basin are held up only by rubble. V In the coming weeks, as crews dig deeper into the debris, work­ ers will install cables and braces to keep the walls from caving in, ■Ss officials said. Where water would go Mayor Giuliani said yesterday i Bracing that when cleanup workers re­ Bedrock;__.^^^i iS§? move material near a wall, it will be done “very, very carefully so there is no damage to it.” If the bathtub gave way, water would rush into the basement PLUGGING levels. With nowhere else to go, THE TUBES the water would drain into two A collapse of the PATH tubes connecting the com­ Subway plex under the Hudson River to bathtub’s retaining the Exchange Place station in walls would send water Jersey City. into the Trade Center If enough water entered the foundation. It would drain tubes, it could eventually reach the PATH terminus at W. 33rd St. Into the PATH tubes. Enough and Sixth Ave. From there, it of a flood could compromise could seep into New York City subway tunnels. Engineers may use ! , subway tunnels. giant plugs to seal the Trade Center 1'/ Bathtub wall Rubble Engineers called that scenario PATH tubes sis a precaution. / highly unlikely, sajmg that even a catastrophic failure of the Trade Center retaining walls I Hudson River B ■

wouldn’t create a torrent large enough to completely flood the Water PATH system. The basin was built over a ——— year in the late 1960s. It spans 16 acres and reaches down to bed­ z rock. Material from the excava­ tion was used as fill to expand I&____ _ Bpath tunnel Proposed plu. Bedrock

a southern Manhattan into the Hudson River, land on which Bat­ 1 tery Park City was built. DAUy NEWS/AP

Officials said they’re confident they can keep the bathtub walls Hahn, a former Port Authority “The plugs would be put in have been pumping water from from collapsing. The Army engineer who worked on the place just in case the water the tubes at a rate of 2,000 to Corps of Engineers is monitor­ Trade Center foundation during would rise,” said Dave Jamieson, 4,000 gallons a minute. Crews 8 04 ing the cavern, and workers its construction, said that any a Port Authority spokesman. have installed pumps in the Ex­ 04’ have installed motion sensors compromised parts of the walls “We don’t want to damage the change Place station, fed large O1 near the walls. can be stabilized. Exchange Place station.” hoses into the tubes and pumped o “A bathtub collapse is wild Millions of gallons of water al­ the water into the Hudson. E speculation,” said Daniel Hahn, Huge concrete plugs eyed Jamieson said workers have of Mueser Rutledge Consulting “We’ve given the Fire Depart­ ready have flowed into the PATH plugged broken mains that were c Engineers, a firm advising the ment methods to make sure the tubes since the Trade Center at­ causing much of the runoff from Port Authority on the cleanup. walls stay vertical,” he said. tack. Officials said much of the the Trade Center. He said all of water came from broken mains, f3 “In a great number of areas below ground, the basement floors are in place and are brae- Still, PATH officials are consid­ ering installing huge concrete plugs in the train tubes leading firefighters’ hoses and rainfall. During the past several days, the water has been pumped from one of the PATH tubes, and a minimal amount remains in the- from the site to New Jersev. contractors working for PATH other.

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