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These
two articles deal with the New York Subway stations at the WTC
not with the Tubes / PATH station:
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Friday,
September 28, 2001
Subway likely to take years to rebuild
NEW YORK CITY -- New York
City Transit officials have determined that damage to the No.
1 and 9 subway tunnels and stations in Lower Manhattan is so
extensive that the line will need to be completely rebuilt for
more than a mile.
The work on the line from just south of Chambers Street all
the way to the end, at the South Ferry station, could take
more than two years, transit officials said this week, adding
that they could not speculate beyond that. They also declined
to estimate the cost because they did not want city, state and
federal officials to hold them to an amount that could turn
out to be insufficient. Transit officials say they expect
money to rebuild the subway to come from the $20 billion in
federal aid that has been pledged to the city in the wake of
the attack on the World Trade Center.
The only guide to what the project might cost comes from rough
estimates for the long-planned Second Avenue subway, which
planners think would cost about $1 billion a mile. But that is
for building a new line from scratch and carving its tunnels
deep beneath the streets. A rebuilt section of the 1 and 9
line would most likely follow the tunnel cavity that already
exists and would cost less.
About 575 feet of the line is totally collapsed, in two
separate locations, but subway engineers who have explored the
tunnels say that hundreds more feet are structurally unsound,
with thick I-beams bent like paper clips and ceilings sagging
under the weight of millions of tons of debris from the World
Trade Center on the street above.
In several places, individual beams from the trade center
weighing tons punched through the street, through about seven
feet of earth and through the concrete-and-brick tunnel
ceiling, and then kept on going into the tunnel floor, where
they remain lodged like spears.
"There is so much damage that it does not make any sense
to rebuild it in sections," said Mysore L. Nagaraja, the
chief engineer for New York City Transit. "There is
really no way to do it that way."
Besides the damage to the 1 and 9 line, a corridor and
equipment room near a wall of the Cortlandt Street station on
the N and R line was punctured by a large section of the
facade from 2 World Trade Center.
Engineers -- who have shored up that station with thick wooden
pillars -- said they were testing the walls and ceilings with
motion detectors called inclinometers to determine whether the
huge breach had left the walls and ceilings structurally
unsound. But even if they are sound, the engineers said,
subway service will probably not resume through those tunnels
for about six months.
The loss of the 1, 9, N and R will be a blow to the west side
of Lower Manhattan as it tries to rebuild and assure residents
and workers that they will not be isolated. But transit
officials, who were unable yesterday to provide ridership
numbers for the affected stations, note that there are subway
lines nearby that can pick up the slack.
Because Lower Manhattan was the population center when the
first subway lines were built, a tangle of lines converge in a
relatively small area -- including the 4 and 5 at Wall Street,
which is only a thousand feet from the Rector Street station
on the 1 and 9. The Bowling Green station on the 4 and 5 is
also a little more than a thousand feet from the 1 and 9 South
Ferry station. And there is the C and E station at the World
Trade Center, which was only slightly damaged and could reopen
as soon as streets above it are repaired and reopened.
Rebuilding about 6,200 feet of the 1 and 9 line, including the
Cortlandt, Rector and South Ferry stations, would be a huge
and time-consuming job under even the best of circumstances.
But in interviews, subway engineers described tremendous
obstacles before rebuilding plans can even be drawn up.
For example, where the line runs beneath West Broadway,
adjacent to the rubble from the collapse of 7 World Trade
Center, many steel support beams in the tunnels have fallen,
leaving sections of the road and sidewalks above with little
underpinning except hope.
To shore up the street so recovery equipment can use it,
transit officials have agreed to pump about 220 feet of the
tunnel full of concrete -- enough concrete to cover an entire
football field a foot deep. Months later, when the debris is
cleared, transit workers will then have to carve away all that
new concrete to rebuild the line.
They will also have to demolish two steel-and-concrete plugs,
three feet thick, that were built Wednesday in the 1 and 9
tunnels near Chambers Street and Cedar Street, to prevent
water from flowing into the rest of the subway if catastrophic
flooding occurs.
The plugs were installed because the 1 and 9 tunnels run right
up against the western wall of what is called the bathtub, the
waterproof barrier that rings the World Trade Center basement
to keep Hudson River water out and that is now threatened.
Considering the devastation near the trade center, and the
fact that the tunnels were only five feet below the road
surface in some places, complete tunnel collapses were not as
extensive as some engineers had feared.
This is partly because the tunnels, opened in 1918, were --
like most of the rest of the subway -- built with steel arches
called bents, spaced five feet apart along the length of the
tunnels. The tunnels are relatively shallow and were built
using the cut- and-cover method, in which trenches were dug in
soft soil and then framed with steel arches. The arches were
surrounded by brick and concrete on all sides, and then this
tunnel "box" was covered over with earth, some
utility lines, sidewalks and streets.
But each arch acts something like an independent structure,
and there are so many of them that tunnels remain intact even
if many arches are destroyed.
John Ferrelli, the chief of infrastructure for the subways,
said he saw the destruction from the deadly derailment of a
No. 4 train at Union Square station in 1991, which knocked out
supports from 28 arches but caused the ceiling to sag hardly
at all.
Ferrelli, who walked through the damaged stations and tunnels
on the 1 and 9 line last Friday, said so much of the line
collapsed because the top of the 2 World Trade tower fell more
to the side than the other tower. The debris crashed directly
above the tunnel that ran along the northeast corner of the
building, crushing a section about 375 feet long.
"We basically had dozens of floors of a huge building
falling from 600 feet right on top of our roof," Ferrelli
said. "It was like a pile driver."
Inside the Cortlandt Street 1 and 9 station, he said, even
where the platform areas remain standing, inch- thick I-beams
fitted with inch-thick support plates are now wavy instead of
straight.
"To have the column buckle and the plate to twist like a
Pringles chip, that takes a tremendous amount of force,"
he said. He described walking toward the south end of the
Cortlandt Street station and noticing that the ceiling sloped
closer to his head as he walked. "It was a strange
feeling," he said.
The other area of total collapse is a stretch of about 200
feet north of the Cortlandt Street station, where the tunnel
ran alongside the eastern side of 7 World Trade Center, the
48-story building that fell after the two trade center towers
did. This is the portion that will have to be stuffed with
concrete to secure the street above until debris is cleared
and subway work can begin. The subway engineers, who have
never confronted a job even a small fraction as complicated as
the one that lies ahead, said they had no idea when they would
be able to dig down and assess the full extent of the damage
in the collapsed sections. They have even less of an idea when
the reconstruction work can begin.
The thing they do know, they said, is that the subway in that
area could have survived the catastrophe only if decisions had
been made 90 years ago to build it very deep below the city,
the way that much of the London Underground was built.
Nagaraja, the chief engineer, said, "I don't think we
could ever design the subway to withstand something like
this."
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September 27,
2001
WTC subway
station likely destroyed
NEW YORK CITY -- The Metropolitan Transportation Authority of
the State of New York said Monday (September 24) the sprawling
subway station that ran under the World Trade Center likely
was destroyed in the Sept. 11 attack.
The MTA's chief engineer, Mysore Nagaraja, in a report to an
MTA committee, said the tunnels that serve the No. 1 and No. 9
lines that run beneath the World Trade Center and the
infrastructure supporting them took heavy damage.
"Eighteen hundred linear feet of the tunnel damaged or
filled with rubble, Cortland Street station probably
destroyed," read the caption on a slide shown by the
chief engineer at a meeting of the Capital Program Committee.
Another slide said simply: "Serious damage to the N/R
line Cortland Street Station."
The MTA is currently focusing on shoring up the damaged
tunnels. Concrete has been poured into the tunnels to prevent
water from the World Trade Center basement from filling them.
Asked how long it will take to rebuild the tunnels, Mysore
told reporters after the meeting: "It may take five to 10
years." Reopening of the station will have to be part of
the grand plan for rebuilding the site, he added.
Two board members said they had not yet heard any estimates of
how much the repair and rebuilding will cost the MTA.
The chief engineer said capital projects were continuing,
although their timeframes will be adjusted, because the agency
assumes the federal government will pay for all the
reconstruction.
All MTA construction workers were pulled off ongoing projects
for two weeks to help in the massive recovery effort that
returned 95 percent of the subway system to service just days
after two hijacked jets slammed into the 110-story twin
towers.
Barry Feinstein, one of the board members, took particular
pains to emphasize that MTA construction workers had worked in
the same difficult conditions as rescue workers, firefighters
and policemen in the recovery effort. "The transit
workers deserve as much credit as anybody in the city. It's
hard, terrible duty."
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