| by Janie Rosman |
A mid-December accident involving one of the two floating concrete batch plants, needed for the construction of the new Tappan Zee Bridge, resulted in Tappan Zee Constructors, LLC (TZC) shutting down both batch plants while it continues to assess the situation.
“One of our floating concrete batch plant silos had a structural failure that caused all three silos on the batch plant to collapse,” TZC President Darrell Waters said in a statement. “The damage appears to be limited to the affected silos and part of the surrounding structure.”
TZC removed the second batch plant to review and inspect its components thoroughly, including the silos. Waters emphasized, “If or when an incident occurs, no matter what the size, we will always use it as an opportunity to review and reassess our safety procedures and operations specific to the project.”
Tilcon New York, the project’s leading supplier of stone, temporarily ceased deliveries and removed its material-containing barges moored at the site.
“The mechanical issues involving the concrete batching plant have obviously impacted the schedule of materials delivery,” company spokesman Geoff Thompson said via email. As of January 16, Thompson said, there has been “no resumption of deliveries yet.”
Limited concrete placement continues: TZC is using the Thruway southbound access ramp and will exit the trestle to the Thruway via the northbound access ramp. Activities on the Westchester and Rockland landings continue “as originally scheduled, as this work has always been planned to receive the needed concrete from trucks to the site,” project officials said.
“People on River Road will not notice a difference,” TZC spokeswoman Carla Julian assured. “It’s always been planned that the land work will have concrete trucks for the abutment. We redesigned the road for longer acceleration.”
Each truck holds about 10 cubic yards of cement, she said, and pours are not more than 200 cubic yards. The bridge builder is working to get the batch plants online, realizing the time restrictions regarding the cement pours. There will be two or three trucks of curing concrete on the access road, since trucks have to be in place before concrete cures. (Curing is a hardening process that protects concrete from losing moisture within a reasonable temperature range.)
As the investigation and project continue, “Safety and environmental stewardship are our top priorities,” Julian and Waters said. TZC continues working on the temporary toll gantry near Exit 10 in South Nyack, and construction crews continue assembling the formwork for the new bridge’s abutment on the Rockland shoreline.
As we rang in the New Year, the resignations of the New York State Thruway Authority Executive Director Thomas J. Madison and Chief Financial Officer Bryan took effect one month after Chair Howard Milstein resigned.
Governor Andrew Cuomo announced new appointments including a replacement for former top aide Larry Schwartz, who alarmed Westchester and Rockland nearly three years ago by citing $14 tolls on the new bridge.
Bill Mulrow will succeed Schwartz, who heads to the private sector. Bob Megna, Public Authorities Control Board’s (PACB) Budget Director since 2009, was appointed acting director of the Thruway Authority. His appointment must be confirmed by the State Senate.
“New ideas and talent are critical to innovation and success. This team will build on the extraordinary progress made over the last four years by bringing experience, energy and fresh perspectives to the table,” Cuomo said. “This is an incredibly accomplished and dedicated group of individuals, and I am proud to welcome them to their new roles. Together we will continue moving New York State forward.”
While January 2015 started year three for Tappan Zee Constructors, LLC (TZC), the super crane’s arrival last October marked the biggest highlight for the state’s $3.9 billion project thus far.
Onlookers gathered at the Tarrytown waterfront in early October and watched the massive crane slowly move under the Tappan Zee Bridge, aided by extra low tide that added a foot or two of clearance space.
While the crane was being prepared for use, TZC construction manager Ro DiNardo said, during an October 28 media tour, “We started pouring concrete into the footings today near the Westchester side, focusing on Pier 39 columns.”
DiNardo smiled when asked about doing things today versus in the past.
“Technology, the way they did things with the first bridge, and the way we’re doing things now, is enhanced,” he said. “I have great appreciation for how they built the Tappan Zee Bridge, and am thankful we have this crane to build the new bridge with better quality and more efficiency.”
Running on Windows 7, and with new computer software, hardware, and a flat panel touch screen, the crane was first prepped – a process that involved getting the frame (versabar) together that will make the placement. It did test lifting in New Jersey, and once it arrived here was working with different spreader bars, and doing practice lifts.
Ron Burgess, who operated cranes as a teenager on the New Rochelle waterfront, will be in the driver’s seat with partner and operator Doug Cormey, and others.
“When they go to set the first beam of the new bridge, the versabar system is capable of picking up 1700 metric tons, which is 1928 US tons,” Burgess said.
Its lifting power — from three diesel-powered main generators and one auxiliary generator that are incorporated into the barge — will enable it to hoist pre-assembled connected steel girders onto the foundation piers.
The first pair of vertical pier towers for the new bridge near the Westchester shoreline rose into the air in November, after which their formwork was removed. Most of the bridge’s 86 columns will support the main span approaches in Westchester and Rockland.