|
Buildings
New York Times Building Aims to Be Steel Landmark
(newyork.construction.com, September 2005 issue)
By Alex Padalka
The 52-story tower will have large amounts
of exposed steel elements supporting an innovative curtain
wall, requiring an intensive fabrication and installation
effort.
With its shimmering skin of high-quality
clear glass and ceramic rods that will appear to change color
as light hits from different angles, the 1.6-million-sq.-ft.
New York Times building has a chance to become an icon of New
York City's skyline.
But one of the 52-story building's most
striking aspects, already evident at the construction site,
is the amount of exposed steel and how the team is accounting
for the effect of the elements and the appearance of the final
product.
"There is nothing in this building
that is not deliberate," said Hussein Ali-Khan, vice
president of real estate development for the New York Times.
The New York Times Co. will occupy the
second through 29th floors - housing all of its New York-based
employees under one roof for the first time - while the upper
floors, with more than 700,000 sq. ft. of commercial office
space, belongs to the Forest City Ratner Cos. of Brooklyn
and ING Partnership, which are seeking tenants for the property
opposite the Port Authority Bus Terminal on 8th Avenue in
Midtown Manhattan.
The occupants will probably never know
the level of precision that the $850 million building's design
is requiring for steel erection. Even basic elements such
as steel connections became complicated on the portions exposed
on the exterior, said Tom Scarangello, project manager at
New York-based Thornton Tomasetti, the structural engineer
on the project.
"Normally, when you're working
out connection details, you're dealing with things like clearances,
but in the end of the day they're going to stick some fireproofing
and sheetrock on it, and no one's ever going to see it,"
he said. "No one cares whether the bolts face this or
that way, nobody cares how thick the plate is, nobody cares
what wall stage you use. But here, both architects were knee-deep,
with us saying 'Which way do we want the bolts to face, and
do we want a hex-head bolt or a button-head bolt©' We
got this stuff detailed out to the point that the iron worker
knows which way the bolt goes."
The architects on the project are Pritzker-prize
winning Italian designer Renzo Piano and New York-based Fox
& Fowle, who created a design that "defies gravity"
and presents an image of lightness and transparency. The design
for a cruciform tower covered in steel, glass, and ceramic
rods also has a base extending eastward that will house one
floor of retail, a ground-floor public garden, and an auditorium,
with the top three floors of that section housing the paper's
newsroom.
The amount of exposed steel elements
gave rise to the first technical dilemma: on a building this
tall, the steel supporting the façade "grows"
with the weather change in the seasons, with the total variation
adding up to a floor-cracking four inches. Thornton Tomasetti
came up with a system of lateral braces and outriggers that
connect the exposed steel to the internal columns and essentially
pins the outside steel to the interior.
The exposed steel also required the
use of a special fireproofing paint and the significant detailing
on each piece that would be visible from the outside. That
process was so unique in New York that Piano's team, led by
Serge Drouin, stayed on site to make sure that each weld and
bolt was made precisely to specifications.
Construction on the project also took
some unexpected turns. The September 11th attacks delayed
final designs, setting back the start of construction. When
excavation finally started, the team made a surprise discovery
in the bedrock.
"The initial borings showed that
we were going to get 40-ton or 20-ton rock on site, which
is very standard for this part of Midtown, and we would have
ended up with spread footing for the tower," Thornton
Tomasetti's Scarangello said. "But as the site was cleared
and we were able to get more borings, it turned out there
was a seam of weak rock going through and around the tower
area, so we had to propose some alternates."
About a third of the tower columns are
now on 22-in. drilled caissons.
Then other hurdles arose. Last year,
the project's steel fabricator, Interstate Iron Works of Whitehouse,
N.J., went out of business, with its owner blaming skyrocketing
steel prices and a tight pre-negotiated contract. The departure
forced the construction manager, New York-based AMEC Construction
Management, to effectively enter a new field and become the
steel supplier for the project.
Steel continued to present not only
technical challenges, but logistical ones as well. Faced with
an expiring contract, steel workers went on strike in late
July, halting construction for days. Despite the delays, however,
the building remains scheduled to open in early 2007.
In addition to the exposed steel, the
concept of transparency and lightness is realized at several
different levels.
On the top of the building, ceramic
rods extend above the roof, partially hiding a 300-ft. mast
that tapers from 8 ft. at the base to 8 in. at the top. The
steel beams grow lighter toward the top as they support less
weight. These details help to give a feeling of lightness;
along with the building's unique curtain wall, popular in
Europe but virtually unheard of on this side of the Atlantic.
Rather than the city's standard reflective
or tinted windows, the curtain wall uses extremely transparent
low-iron Starphire glass, fabricated by Viracon of Owatonna,
Minn., and low-e VE-2M coating. This arrangement leaves the
interior vulnerable to glare and heat gain, a problem the
Times and its architects did not want to address with power-hungry
air conditioning units.
To that end, the team came up with a
twofold solution for the windows that covers the exterior
with 185,000 ceramic tubes manufactured by Germany-based Haldenwangere.
The tubes dissipate solar light before it enters the offices,
while allowing the color of the building to change with the
sky. Inside, sensor-controlled solar shades automatically
adjust to various angles of the sun throughout the day and
different seasons. The team built a 4,500-sq.-ft. mockup of
the system and performed extensive testing in what Glenn Hughes,
the paper's director of construction, calls a "pagan
experiment," because it measured natural light from solstice
to solstice using 100 real-time sensors.
While the owners decided not to pursue
U.S. Green Building Council LEED certification, a process
that requires additional overview and cost, the team realized
several energy efficiencies.
Some were inherent in the paper's needs,
such as keeping its time-sensitive operations running during
power blackouts. The team will install an onsite 1.4 mW co-generation
plant burning natural gas, with the byproduct heat recovered
and converted to hot water. The curtain wall and lighting
design provide additional energy efficiencies, along with
an underfloor HVAC system on the Times-occupied floors. Forest
City decided to leave its floor layout options to the tenant.
Instead of the usual overhead air distribution,
Flack + Kurtz, the New York-based mechanical engineer on the
project oversaw installation of the underfloor circulation
system that saves energy by allowing cold air to rise on its
own, concentrating the desired temperature in only the lower
60 percent of the space where it's needed. The fully adjustable
floor ducts allow customization anywhere in each floor's 32,000-sq.ft.
space.
"The unique aspect is that it will
be the largest underfloor air distribution system in the city,
and the first high-rise with underfloor air displacement ventilation,"
said David Cooper, managing director of Flack + Kurtz.
|
