|
Buildings
WTC Cleanup Management Shifts as Debris Disappears
(enr.com 12/24/01)
By Debra Rubin
 |
| GRIPPING
Section of remaining tower facade is lifted off site.
(Photo by Michael Goodman for ENR) |
As visible signs of the World Trade
Center devastation fast disappear, cleanup officials confirm
plans for project management changes that will better conform
to the site's changing profile.
Work crews last week brought down the
last remnant of the twin towers, the 205-ft-high northeast
corner of WTC One. Using high-powered Oxylance cutting torches,
workers precut and then dropped the facade in 20 pieces, each
weighing 57 tons, says David H. Griffin Jr., vice president
of D.H. Griffin Wrecking Co., the project's Greensboro, N.C.-based
demolition consultant. The tower remnants are to be transported
to John F. Kennedy International Airport for temporary storage
until decisions are made for their use in a future site memorial.
Crews are also close to bringing down
WTC Six, the last standing structure above grade at the site.
An eight-story, 75,000-sq-ft section was felled Dec. 18, with
precut columns attached by cable to excavators that pulled
at them. "We rocked the section," says Griffin.
"It fell like an implosion." The rest of the burned
hulk was set to come down by the end of last week.
Workers also began extricating the first
of the complex's seven chiller plant units, says Peter Rinaldi,
engineering program manager for the Port Authority of New
York & New Jersey. "We are following a plan to excavate
from east to west," working off an area that's solid,"
he says. Each unit weighs at least 100,000 lb, and will be
removed by Hitachi excavator models 750 and 1200.
Rinaldi says the amount of chiller damage
indicates that most freon inside has already escaped. But
air monitoring is extensive in the area and in excavation
equipment, he says.
Debris removal is "opening up areas
not searched before," says Rinaldi. Excavation for tieback
installation along the site "bathtub" uncovered
a buried fire engine and stairwell remnants in which new victim
remains were discovered.
Michael Burton, executive deputy commissioner
of the city's lead cleanup agency, the Dept. of Design and
Construction, says that as progress continues, agency officials
and remaining contractors are now "transitioning to a
unified field management team" that will eliminate the
"quadrant" system of work.
"The complexity of the job is being
reduced, and the quantity of private construction staff and
city employees will drop as well," he says. DDC will
still oversee site management, says Burton. But more responsibility
for day-to-day operations will revert to a contractor team
that is likely to be headed by Bovis Lend Lease and amec.
Officials are now working out the new "scope and responsibilities,"
says Bill Cote, a top assistant to Burton. He did not disclose
additional details. But the management shift is set to be
implemented by mid-January, Cote says.
|
