A Chilling Account:
Hudson /York’s First-Hand Experience Recovering Gas Six Stories
Below ‘Ground Zero’
NEW YORK CITY - It was one week shy of three months since the catastrophic
events of September 11th at the World Trade Center and "Ground Zero"
smoldered as a danger still lurked some six stories below. Known as
an HVAC industry marvel, 12 giant York chillers that once cooled
some 35,000 WTC occupants were left crippled and condition unknown
since the two behemoth 110-story towers came crashing down on that
fateful morning.
Among the immediate safety concerns for the hundreds of rescue and
construction workers at the site was the status of the refrigerant
in the large chillers that lay far beneath the massive pile of
broken concrete and twisted steel. The fear was that heat from
inferno-like fires above may turn leaking refrigerant into a highly
acidic vapor or since refrigerant weighs more than air, the chemical
coolant would displace oxygen making it difficult or impossible to
breathe.
The calls quickly went out first to DuPont and York International,
the manufacturer of the chillers as well as the service contractor
for the World Trade Center. Both companies, in turn, called Hudson
Technologies for its experience and expertise in handling the most
challenging refrigerant related issues and problems. This would be
no simple, straightforward recovery. Hudson has done thousands of
large chiller refrigerant recovery and decontamination jobs across
the country. These have included aircraft carriers, submarines and
nuclear power plants, as well as large comfort cooling and process
cooling systems. Hudson was called in for its engineering and
chemistry knowledge, which has been a company hallmark since it was
founded a decade ago.
Within days of the collapse, several attempts were made by Ground
Zero crews to reach the giant chillers, including using remote
cameras, but damage to the surrounding area was too severe and
dangerous. It wasn't until a full two months later that Ground Zero
engineers and the Hudson/York team, fronted by New York City
firefighters who,
while working in knee-high water, sledge hammered their way through
concrete walls and steel doors, could reach a mechanical room and
examine some of the chillers six stories down. Large slabs of
concrete from above visibly crushed many of the chillers, but two
others were found intact with speculation that they still contained
gas.
York International and Hudson Technologies were charged with
writing the engineering specifications for the gas recovery under
the supervision of the New York City Department of Design and
Construction (DDC), which is overseeing all work at Ground Zero. The
Hudson/York team worked closely with the Environmental Protection
Agency, the Port Authority of New York & New Jersey, Bovis
Construction and the DDC to develop the parameters, strategy and
tactics for recovering the refrigerant found in one of the enormous
chillers. Safety was paramount in the planning and every effort was
made to ensure all steps were carefully calculated and all
precautions taken.
With a New York Fire Department approved emergency evacuation plan
in place, Hudson rolled one of its 40 ft. tanker trucks into Ground
Zero, parking it only feet away from the large upright cross made by
a falling steel beam that has stood as a symbol of prayer and
remembrance of the terrorist attack victims.
The Hudson/York team snaked about 700 feet of hose from the tanker
down five stories to a hole in a double slab of concrete just big
enough to crawl through that was created earlier by the
firefighters. From there the team entered a stairway in pitch
blackness and in knee high water maneuvered around broken pipes,
fallen concrete and other debris and down one more flight to one of
the mechanical rooms.
The team was equipped with flashlights, but the darkness was so
intense that it quickly swallowed up any light. Hooking up the hoses
to the York chiller valves became as much a touch and feel as actual
sight since the bottom of the chiller was submerged under water. The
team described the entire experience as very eerie and chilling, and
they weren't talking about standing knee-high in water and the
coolness of the air. As one of the technicians recounted "the
equipment room resembled a war zone cast in complete darkness."
The Hudson/York team worked over three days, Dec. 4 - 6, from 7 p.m.
to 5 a.m., when excavation crews above ground were not working. The
team was outfitted with detectors that measured refrigerant, carbon
monoxide, hydrogen sulfide and oxygen in the air, and each carried a
supply of oxygen while underground.
The recovery was completed without a hitch as per plan. The success
was attributed to the combination of York's knowledge and experience
in the servicing of large tonnage chillers and Hudson's expertise in
developing customized solutions to complex refrigerant-side problems
including extraordinary refrigerant recoveries. The Company used its
patented Zugibeast®,
an ultra-fast machine designed and developed by Hudson, to recover
the refrigerant. The Hudson/York team may be called in again if
other units are discovered as the excavation work continues and
other mechanical rooms with chillers are made accessible.
