Project Challenge:
The Philadelphia International Airport (PHL) determined that
a new, taller Ramp Control Tower was necessary to provide clear
sight lines to the taxi lanes and gates of its new Terminal
One facility. The tower would need to be constructed as a design-build
project to ensure operation before the new terminal was opened
and would be the most visibly prominent structure at the airport.
With limited available real estate on the land-side, and flight
envelope constraints on the air-side, the 182' tower needed
to be constructed in an existing planter bed with a footprint
of only 20' by 32'. In addition, the tower cab needed cantilever
out toward the airfield by 30' from the core to provide the
required sight lines.
Klein and Hoffman (K&H) collaborated with PGAL Architects
to create a structure that provided a bold architectural statement
while meeting all the functional requirements of PHL.
Project Solution:
The four-level tower cab needed to provide a 275-degree clear
sightline and space for 21 work stations. In order to minimize
column sizes, minimize tower weight and accommodate the tight
construction schedule, structural steel framing was selected
over reinforced concrete. The cab is configured as an inverted,
truncated cone so that the glazing could be inclined 15 degrees
downward to control glare on the airfield. The cone is formed
from steel spokes supported by a center column and thin, widely
spaced perimeter columns sized to maximize unobstructed views.
The tower core is comprised of six columns, each supported by
a 72" diameter by 60' deep concrete caisson. Steel anchor
piles were embedded full depth into the caissons to resist the
significant overturning forces on the columns from wind and
seismic forces and the unsymmetrical cab configuration. To accelerate
construction, the foundation work was bid as a separate package
and construction began while the tower design was being finalized.
CLIENT: U.S. Airways, Inc.
OWNER: Philadelphia International
Airport
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