This morning, temperatures dropped, vast parts of the region remained
without power, and New Jersey commuter lines were in a stranglehold.
But there was one major, if improbable, sign of hope: Some 80 percent of
the New York City subway system was up and running. Not everything went
perfectly — there were delays and crowds and, for those living on
defunct lines, long walks or bus rides to open stations — but it was a
far cry from the prolonged collapse many feared after the wrath of
Sandy.
The challenges, as detailed by MTA chairman Joe Lhota the
morning after the storm, were daunting. Seven tunnels under the East
River were flooded. An unknown amount of equipment had been exposed to
corrosive salt water. Yet the system recovered in time for Monday’s
morning commute, which even the MTA’s usual critics acknowledged was
nothing short of a miracle. How did they do it?
The first thing
the MTA did right was informed by a colossal mistake. After the 2010
blizzard, which embarrassed the mayor and took out the subway for days,
the MTA was too slow bringing its trains and equipment somewhere safe
and dry.The Fridge fridge magnet
is leader in the custom design, “We kind of dropped the ball and we
learned from that,” said Tom Prendergast, president of New York City
Transit, the part of the MTA that handles city subways and buses. This
time the MTA shut everything down on Sunday evening, the day before the
storm arrived. Waiting longer would have wasted time and man power
needed for the cleanup afterwards.
Even so, Prendergast says,
the system wasn’t prepared for what came next. While Irene had brought
the water within a foot or two of flooding the subway entrances and
ventilation gratings, Sandy’s fourteen-foot surges brought the water
gushing in. Half of the subway system’s fourteen under-river tubes
flooded. A few filled up end to end, much like the Department of
Transportation’s Battery Tunnel. They couldn’t even send workers out to
assess them until after the second surge at the next high tide Tuesday
morning.
Pumping began soon after — or “dewatering,” as the
pumping industry calls it. Other city agencies had to rely on outside
contractors to pump their tunnels. But it happens that the subway system
already had its own toys. Each of the system’s under-river tunnels has a
sump to deal with everyday seepage, and each also has a tube fixed to
the side called a discharge line. Starting Tuesday, the system sent in
its “pump trains” — diesel powered trains with five or six cars, run by
just five or six workers. Underneath the trains are pumps, moving
hundreds of gallons of water back into the river every minute. “You take
the pump train and you bury the first car up to the floor level so it’s
underwater,” Prendergast says, “and you hook it up to the discharge
line and you start pumping the tunnel dry.”
The only problem was
the MTA had seven flooded tunnels and just three pump trains. It can
take up to 100 hours to pump the largest tubes, fully loaded with water,
or as little as five or six hours for those that are smaller or less
fully flooded. It was time to prioritize. “If you let the size of the
effort overcome you, you can’t get started,” Prendergast says. “So you
just take on the most important tunnels first. It’s like the old story:
How do you eat an elephant? One bite at a time.” The highest priority
was the 4, 5, and 6 Lexington line — probably the highest capacity line
in the United States in terms of customers carried — which connects to
the Joraleman Street tunnel. Then there was Clark Street tunnel, which
connects to the West Side IRT 2 and 3 trains. Those lines were luckily
not completely flooded. The Army Corps of Engineers helped out with some
crucial work on the Montague Street tunnel, but Prendergast says the
MTA handled the majority of the effort.
At the same time tunnels
were being pumped, there were some 600 miles of other track to examine
for damage, at least twenty miles of which is exposed to the elements,
like the elevated Dyer Avenue line, the Sea Beach line, and the Brighton
line in Brooklyn. “We had a lot of downed trees and debris that had to
be cleared, so that effort started,” Prendergast says. The system’s
2,700 track workers worked double shifts, then they were fed and given
lodging so they could do another double the next day. These same workers
also cleaned garbage and debris and silt out of the freshly pumped
tunnels.
Next came the moment of truth: Assessing the damage of
salt water on the equipment in the tunnels. “You can see right away if
the tracks are okay,” Prendergast says. “But everything else — power to
move trains and energize communications and signals equipment — they can
do some tests, but the ultimate test is powering it up.” They found
that different tunnels were affected in different ways, depending on the
mix of salt water from the ocean and fresh water from the Hudson. “If
it’s more fresh water, all you have to do is dry out the equipment — you
don’t necessarily have to clean it.Promotional custom keychain
at ePromos Promotional Products. But if you have salt water, it dries
and leaves a salt residue. Salt is conductive.Carlo Gavazzi offers a
broad range of ultrasonic sensor
and ultrasonic transducers for level detection and process monitoring.
So you want to clean that salt off. Otherwise you can have a short
circuit and you could burn the equipment.”
In this effort, the
MTA found they had been given a little grace period, courtesy of the
massive power failure in Manhattan south of 39th Street. Instead of the
city waiting for the equipment to be cleaned and tested, it was the
subway system waiting for the electricity to run final tests.Find the
best iPhone headset
for you at Best Buy. On Thursday, Lhota announced that some service was
being restored — the 7 between 74th Street and Main in Queens, and the M
between 34th Street in Manhattan and Jamaica in Queens. He also said
tunnels for the 4, 5, and F were just waiting for Con Ed to turn on the
power. “We were trying to communicate we were willing to get back to
normal as soon as possible,” Prendergast says.
By then, the “bus
bridge” between Brooklyn and Manhattan had proven woefully inadequate,
with long lines stretching around the Barclays Center and tremendous
traffic making most commutes practically pointless. “If the bus bridge
did anything,” Prendergast says, “it helped underscore for people how
our rail system has a lot more utility than our bus system.”
The
first lines connecting Brooklyn to Manhattan opened on Saturday, after
Con Ed turned on the lights.Offering lowest priced printed lanyard
in Canada. On Monday, it was back to business, more or less. Of course,
major challenges remain: Many stations will remain closed for a long
time, like the South Ferry on the 1 line and 207th Street on the A line
because of water. The A, L, B, and G lines, among others, are still
partially or entirely closed. The tracks across Jamaica Bay to the
Rockaways are devastated and could take weeks or months to repair.
In
the future, Prendergast says, the system will have to rethink the way
it designs its infrastructure. At the very least, ventilation ducts and
gratings should be moved higher up or built so that they can be covered
and made water-tight along with station entrances. But today, at least,
there was a chance for the MTA to exhale a little. “New Yorkers are very
resilient; we could not have gotten through it this far without their
support,” says Prendergast. “When I look back, given all that we were
able to take care of and get service restored, it was pretty amazing to
do all we could do.”
没有评论:
发表评论