BRIDGE

deck. Stressing of the stay cables was performed at the deck level,
securing each strand simultaneously from both ends. The highdensity
polyethylene tubes that house the cables prevent exposure
to outside elements.
“Tilikum Crossing was the first United States implementation
of commercially available tower saddles to support cable stays,”
Treyger said. “This let us design short, solid concrete towers and
keep the project as economical as possible. Few bridges in the
world have been completed using this technique.”
SMALL FOOTPRINT, COMMANDING PRESENCE
Though cyclists, pedestrians and transit users may not notice,
Tilikum Crossing has a small footprint. Even so, pedestrian and
bike paths on each side of the bridge are 14 feet wide, the widest of
any Portland bridge. They’re even wider where they wrap around
the towers.
“One of the larger issues we had to address with this design was
comfort for bikers, pedestrians and trains going across the bridge,”
Treyger said. “Detailed, dynamic studies were completed by HNTB
during preliminary design to ensure that all riders on the bridge
would be comfortable if they were present at the same time or if the
bridge was at full pedestrian capacity.”
Typically, cable-stayed bridges are taller than Tilikum Crossing.
However, it is only 100 feet above the Willamette River surface.
Residents didn’t want it competing with the Ross Island Bridge or
the Marquam Bridge, so it had to have a calculated presence.
In addition to its airy daytime presence, its nighttime impression
is a standout. An aesthetic lighting program controls 178 LEDs that
illuminate the bridge. The program is connected to the river and
monitors and adjusts the color of the lights according to the river
height, speed and temperature.
TEAMWORK EVIDENT
After seven years of planning, design and construction, Tilikum
Crossing was ready for service. Tests had been run, transit operators
trained and final systems were checked one last time. After a
celebratory grand opening weekend for the crossing and Portland’s
new Orange Line rail transit system, Tilikum Crossing, Bridge of
the People, opened for business on September 12, 2015.
“I’ve been impressed by the craftsmanship provided by the Kiewit
and HNTB teams,” Bob Hastings, agency architect with TriMet, said.
“Those teams helped create an extraordinary bridge. We’re hearing
continually from the public about their appreciation of its design.”
Just a month after opening, Portland-Milwaukie officials were
getting similar feedback, as well.
“The bridge is performing well and has met with huge public
acceptance and compliments,” Tertadian said. “The leadership and
technical expertise demonstrated by HNTB were critical to the
success of this project.”
Building this bridge brought challenges, but innovation, creativity
and technical expertise brought it to completion.
“Because TriMet and HNTB listened to residents, worked with
area businesses and incorporated their ideas, Tilikum Crossing
truly is a bridge of the people,” Treyger said. “It’s one that we all
can be proud of.” n
CONTACT:
SEMYON TREYGER, HNTB Project Manager
(425) 450-2591 n streyger@hntb.com
Tilikum Crossing
Honors Native People
Honoring native residents of the region, TriMet named
Portland’s 12th bridge “Tilikum Crossing.” “Tilikum” is
drawn from the Chinook Wawa language that was used by
Native Americans and newcomers to the area for centuries.
Tilikum means “people,” “tribe” and “relatives,”
and symbolizes coming together. Over time, it also has
come to mean “friends.”
The name honors the Cascade, Clackamas, Mulnomah
and other Chinookan people who have lived in the region
for 14,000 years. It was chosen for the bridge from nearly
9,500 name submissions made by Portland-area residents.
Once the bridge was named, many citizens were made
aware of the connection these tribes have to the nowurban
area, creating a new sense of heritage.
Chet Orloff, a historian who headed the committee
to name the bridge, noted late last year that the bridge
conveys the concept of community. He said as people
historically crossed the river in groups via canoes, they’ll
now cross in groups by walking, biking or by riding. n
Descendants of local Native American
tribes attended the grand opening of
the Tilikum Crossing bridge, wearing
ceremonial dress to showcase their
heritage and its impact on the Pacific
Northwest.
HNTB DESIGNER Number 105 Page 15