TZB Year Four: Progress and Milestones
Filed under: Educational Outreach, Governor Andrew Cuomo, I Lift NY, New NY Bridge, New York State Thruway, Tappan Zee Bridge, Tappan Zee Constructors LLC | Tags: Educational Outreach, girders, Hudson Valley P-TECH, I Lift NY, Jamey Barbas, Liberty Elementary School, main span towers, New NY Bridge, New York State Thruway Authority, South Nyack, stay cables, toll plaza |
Construction on the new 3.1-mile, $3.98 billion project progressed at a brisk pace since June and reached a halfway point in early August.
The new towers — several now with stay cables that are also attached to roadway — and blue girder assemblies paralleling the current span are most apparent. There’s more.
Main span towers and cables
This summer Tappan Zee Constructors, LLC (TZC) began installing the first of 192 stay cables (July) on the as-yet-unfinished westbound towers to the main span road deck. Each cable contains bundles of metal strands covered in protective sheaths; placed end-to-end the total is 14 miles of sheathing encasing 700 miles of strands.
By September the westbound towers reached their eventual 419-foot heights, and crews removed the self-climbing forms to reveal chamfered (angled) tops.
Twelve pairs of cables are anchored to each side of the towers and tensioned to outside sections of structural steel. The cable bundles increase in size as they move away from the towers to support the 74-million-pound main span roadway.
All four westbound towers are finished; the eastbound towers will be finished by this month. At press time (mid-November) more than 40 of the 192 cables were installed on the westbound span; when finished, crews will focus on the eastbound span’s cables.
Constructing the roadway
Also in July the first 40-foot-long steel sections and prefabricated road deck panels were installed across the main span crossbeams and working outward in each direction.
When the steel and deck panels extended far enough from the crossbeams — as when the towers reached a certain height — workers began attaching and tensioning the cables that will support the main span roadway, and then the roadway will built across the main span channel.
Final structural steel was installed as much as can be on the eastbound span in mid-September and completed on westbound span in early October. Crews are now installing road deck panels.
By next spring/summer traffic will shift to the westbound span so the super crane can start dismantling the current bridge, and work will resume on the eastbound span.
The first LED roadway lighting stanchions (columns) were attached to the westbound span, and workers installed three “turnarounds” — two on the Rockland approach span and one on the Westchester approach span — so emergency responders can quickly get to the either span in case of an accident.
Water lines were installed underneath the bridge’s roadway and will connect to hydrants staggered on the inside and outside lanes. These hydrants will be fed from a dry system (not filled with water until needed) in winter and a water-pumped system during summer months.
The five-year program corresponds to each year of construction and explains the project clearly using understandable terms. Presentations include visuals, examples and props — a piece of galvanized steel rebar (piers, towers), a section of metal strand (stay cables), a square of clear plastic (border wall of walking path).
Educators like Cottage Lane Elementary School teacher Jacob Tanenbaum say they “match exactly what our (technology and science) students are studying in their various classrooms,” which is bridge design.
Engineering, information technology and green building (sustainable design) students at Hudson Valley P-TECH (The New York State Pathways in Technology Early College High School program) in Piermont were interested in traffic patterns when the current bridge is dismantled and how the new bridge will carry the same 140,000-per-day vehicle load. Others wanted to when the spans would open, project costs and projected tolls.
“We have a group of engineering students who are Engineering 105 right now,” P-TECH Principal Natasha Shea. “It’s part of their curriculum with RCC, and they have to design and build a bridge, so this fits into what they’re learning.”
Marjan Perry’s third-grade class at Liberty Elementary School reads the fictional Pop’s Bridge by Eve Bunting about two boys whose fathers are helping build the Golden Gate Bridge. “They learn all jobs are important, and that projects require teamwork,” she said.
The new bridge is featured in Nyack Public Schools’ new logo created by several high school art students and on the district’s home page. Its inscription reads, “Building bridges for today’s students to cross into tomorrow’s world with equality, innovation and optimism.”
“When I was your age I didn’t know what an engineer did, I didn’t know any engineers,” or in high school or on college, Project Director Jamey Barbas told a group of sixth and seventh-grade girls recently.
Several in Barbas’ workshop about bridge structures — part of a WizGirls conference hosted by AAUW Westchester that encourages young girls to explore technology and computer science — nodded. After learning about tension and compression, they applied their new knowledge by assembling mini LEGO® bridges.
“Events like (these) are unique opportunities to bring awareness to young women of careers in engineering,’ she reflected later. Equally meaningful was her message that you can always change direction.
Barbas was a premed student and took a biomedical engineering class in college, thinking it would assist her in medicine. Intrigued, she switched her studies and career goals.
To comply with the DBE (Disadvantaged Business Enterprise) program, mandated by the US Department of Transportation for federally-funded projects, TZC committed to a 10 percent goal ($314 million).
The project costs $3.98 billion ($3.14 billion plus administrative and contract costs)
Through September 2016 TZC recorded $247.9 million in contract-value commitments to DBE firms. Of the 245 trade contractors and professional firms hired for the project, 112 are DBE firms.
One contractor, New York Geomatics, provides surveying and layout.
“We do the office engineering via state-of-the-art computer programs, figuring where to drill, where to pour the concrete and where to place the steel,” Senior Project Surveyor Nobile Basile explained. On the bridge project it places up to four two-man survey crews on the water, and two two-person crews on land, daily.
In some cases, the company devised innovative ways to use equipment for some tasks.
Basile observed during the past three years, “Some surveyors lay out a high rise building, some work on roads or boundary; this project involves every type of surveying and layout, including some in-house, out-of-the-box solutions, It’s been a challenge but we’ve been able to meet expectations.”
Workers began prepping the former toll plaza site in Tarrytown for foundation work on the new 26,000-square-foot Thruway Authority maintenance facility. Traffic shifts in October and November paved the way for crews to start building the new state police barracks south of the Thruway.
“Our consulting firm, VHB, is writing its final analysis for how we can develop Interchange 10 and make it profitable for our residents,” South Nyack Mayor Bonnie Christian, said excited about the positive plans for the village. TZC is using those 14 acres as a staging area.
Last month the Thruway Authority and the village jointly presented South Nyack’s preferred concept, “Alternative F,” for the shared use path and terminus to the community. “We’re pleased both the Thruway Authority and the state were sensitive to our needs,” she said.
For information about the project or its educational outreach program, visit http://www.newnybridge.com/contact/.
Photos courtesy of New York State Thruway Authority and HJ.
Copyright © Janie Rosman and Kaleidoscope Eyes 2016