Opportunity
is like noise - when it knocks it shouldn't be ignored. In
1991, opportunity called on John Barrett, President of ATCO
Noise Management Ltd., Calgary, Alberta, Canada. "Lafarge
Canada Inc. had contracted my company, ATCO Metal Ltd., to
provide cladding for a sound absorbing steel barrier it was
building in Edmonton, when it decided to get out of the noise
abatement business. From that time on, there's been no looking
back," said Barrett.
The
"no looking back" involved Lafarge's decision to sell its
acoustical technology just as Barrett was searching for ways
to keep his metal business afloat within a depressed steel
industry. Lafarge's acoustical technology grew out of the company's
attempts to develop sound absorbing concrete. Working with
the University of Alberta's Mechanical Engineering Acoustics
and Noise Unit, Lafarge created an acoustical "sandwich" made
out of metal, Mylar, wood and acoustical batting. "I bought
Lafarge's technology because I believed ATCO Metal could use
it to augment its product line. We fabricated cladding. Now
we also fabricated acoustical panels," said Barrett.
In
1991, ATCO Metal used the acoustical sandwich to construct sound
absorption barriers along rapid rail routes in Calgary, Alberta
and Vancouver, British Columbia. "Noise control was still
secondary to our main business of making pre-engineered metal
buildings," said Barrett. "However, when we acquired Lafarge's
technology, we also acquired its acoustical R&D team.
Over the next few years this team developed a series of absorptive
and reflective assemblies for walls and roofs."
The
combination of buildings and acoustics proved to be a winning
one for ATCO Metal. acoustical buildings to deaden the noise
at two of its compressor stations were exactly what TransCanada
PipeLines needed in 1992. At that time, TransCanada was expanding
its main pipeline. In a network that snaked 8,700 miles (14,000
km) across Canada, expansion meant new compressor stations
in noise sensitive areas. "Near several cottage communities,
we had to build stations with noise levels as low as technically
feasible. This meant achieving levels of 33dBA for each station
component, such as the gas turbines and compressors," said
Marie Standing, TransCanada PipeLines' acoustical engineer.
The TransCanada PipeLine contract was the first time ATCO Metal would
build something other than barriers. ATCO used the same approach
as it had for its barrier construction - prefabricating and
shipping acoustical panels for installation at the site. "It
soon became apparent we had to reinvent our product," said
Barrett.
The
company found that multiple panel joints decrease a building's
acoustical performance. Shipping prefabricated panels is costly
and some panels arrive damaged. When changes are made to a
station's design after construction start-up, panels need
re-sizing. Moving long, heavy panels across trenches and
over uneven ground is also back-breaking work. "Back we went
to the lab. What we came up with were seamless roof and wall
assemblies. Not only did they acoustically outperform the
panels but they were cheaper and faster to build," said Barrett.
ATCO's
new seamless walls and roof products are assembled in-situ.
"We'll construct a whole wall or roof using a layered
approach: first a perforated liner, followed by a vapor barrier
in cold climates, one or more layers of our acoustical materials,
a septum layer or layers, then exterior cladding," said Barrett.
The wall and roof assembles are supported by pre-engineered
steel. The interior surface absorbs noise and minimizes reflection.
The exterior is sheet metal finished in baked-on enamel paint
for a maintenance free surface. In-situ construction also
translates into cost savings since most materials and labor
are sourced locally.
In
1993, ATCO applied its layered technology at five TransCanada
PipeLine stations. Three stations at Dryden, Smooth Rock
Falls and Barrie, Ontario required maximum attenuation to
meet noise levels of 33dBA at 300 feet. Noise sources consisted
of a gas generator and power turbine (90 dBA at 1 meter);
two centrifugal compressors (105dBA at 1 meter), gas generator
air inlets, turbine exhausts and lube oil coolers; one inlet
and exhaust duct with fans; four exhaust fans; and high pressure
gas and lube oil pipes. ATCO Metal assembled 23"acoustical
walls, then installed acoustical doors, roof and ventilation
systems to achieve the three highest performing acoustical metal
buildings in North America.
ATCO's acoustical expertise had begun to attract other gas transmission
companies with noise problems, convincing Barrett that noise
was his company's future. He persuaded his parent company,
ATCO Ltd., to sell the metal side of the business, while allowing
him to keep his acoustical team as the core of the new ATCO
Noise Management. "Our growth opportunities were on the acoustical
side. Energy companies were having to meet more stringent
regulations and the public was also demanding that companies
treat noise problems at their existing sites," said Barrett.
Throbbing
noise from gas compressor stations, especially older models
with reciprocating engines, can be a constant reminder to nearby
residents. Many residents are sympathetic,
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| Iroquois
Gas |
but because
noise has increased from other sources - traffic, blaring stereos,
airplane engines - more complaints are being registered. Gas
transmission companies are reducing noise with new acoustical
buildings or station upgrades. "Our specialty is dealing with low frequency noise; the kind
that comes from pumps and compressors," said Barrett. "Low
frequency sound travels much further than high frequency and
easily bypasses barriers, which makes it tough to acoustically
treat."
A
tough assignment for ATCO Noise Management involved noise
abatement for Iroquois Gas Transmission's Wright and Croghan,
New York, stations. The stations not only had to achieve design
goals of 42dB at Wright and 40dB at Croghan, monitored at
300 feet, but they also had to blend in with the rural countryside.
ATCO treated each significant noise source-gas turbines and
compressors, exhaust and intake, oil cooler, cooling and ventilation
fans-then built the compressor stations to look like barns.
Wright's station is barn red with cupolas, a weather vane
and exhaust stacks that resemble farm grain silos. The Croghan
station is green like the Adirondack Mountain forests and
wetlands where it resides.
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| BOC,
Poland |
Acoustical
tests of the Wright and Croghan stations so impressed a noise
consultant that he recommended ATCO Noise Management to his
client-BOC Process Plants, an oxygen manufacturer headquartered
in the United Kingdom. BOC needed acoustical treatments for
a plant it was building in Pila, Poland.
Timelines
were tight-six months from design to plant start-up-and a
building permit for a foreign company can take months to get.
ATCO met the deadline by subcontracting the acoustical construction
to a local company, Pil-Building. And, as a measure of good
faith, it pre-paid one-third of the subcontract-greeted first
by disbelief and then broad smiles from Pil's management.
After Poland, BOC awarded ATCO six acoustical contracts.
A challenge
of a different sort involved Northwest Pipelines' acoustical retrofit
of its three compressor stations in Sumner, Snohomish and Sumas,
Washington. Before ATCO could treat the noise sources, it had
to remove transite (asbestos) materials from the old model buildings-something
the company had never done before. Noise-absorbing layers of
acoustical materials were then applied to the exterior of the
buildings so as not to disrupt the stations' operations. All
access doors were fabricated for acoustical control. Noise-containing
gaskets were used around the doors. Gaskets and acoustical caulk
were used to seal openings where pipes and other systems ran
through the walls. As
well, noise was captured at ventilation inlets and exhaust outlets
by silencers. "Ventilation openings are a major source of equipment
noise leakage, and fans generate noise. The HVAC system must
be considered in the overall acoustical design to gain best results,"
said Barrett.
Northwest
Pipeline's (Williams Gas Pipeline)
compressor station
at Sumas, Washington |
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| Before
Acoustical Retrofit |
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| After
Acoustical Retrofit |
Best
results were needed when TransCanada PipeLines expanded its
gas transmission network by 13 units in 1997. ATCO achieved
design targets to reduce 105dBA interior noise to 36dBA at
300 feet for two stations and 39dBA to 44dBA at the remaining
11. "In fact, one of the stations runs so quietly, that a
nearby resident asked when it'd be operational," said Standing.
According to ATCO's Barrett, "We were able to achieve the
goals by considering all noise sources in the design. Doing
this saves money, which is our responsibility to provide to
our clients."
Barrett's
responsibility is to also mitigate noise. Like noise, his
business is growing. In February, he opened a European office
in the United Kingdom. "However, there's still a great deal
to be done in North America. Older power generation facilities
are expected to be replaced with gas-fired ones, which are
more efficient but also need acoustical treatment. Also, when
a compressor station is upgraded, its noise levels can go
up. The large number of aging stations located near populated
areas means noise control will be more important than ever
before," said Barrett.
Barrett's insistence that noise is the future, is backed by the ATCO Group
of Companies, a $4 billion in assets, 5,600 employee group
that has successfully operated in 90 countries. "The financial
stability and depth of the ATCO Group is one reason why we
can guarantee the acoustical performance of our work," said
Barrett. "Of course, the foremost reason is that we know how
to stop noise like no other company can."
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