The explosives will detonate above the surface of the water

State contractors say the old bridge had become structurally unsound

Piermont Police say the village's pier will be closed to vehicle traffic that morning

State contractors will use explosives to take down the eastern portion of what remains of the old Tappan Zee Bridge on Tuesday, Jan. 15.

The demolition was originally set for the morning of Saturday, Jan. 12, but was postponed because high winds were expected.

According to a fact sheet obtained by The Journal News, explosive charges will be used to detonate vertical support columns on the bridge's east anchor span closest to the Westchester side. The explosive charges will be timed so that the bridge falls eastward, away from the main navigation channel.

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Traffic on the New York State Thruway across the new Gov. Mario M. Cuomo Bridge will be stopped in South Nyack and Tarrytown while the old bridge is dropped into the river.

Steel will then be recovered by marine salvage teams using chains that have been laid on the riverbed and, over the coming weeks, removed by barge, according to the fact sheet obtained by The Journal News/lohud.com hours before Tappan Zee Constructors announced its plans.

The river’s main navigation channel and the New York State Thruway will also close between Exit 9 in Westchester County and Exit 11 in Rockland County during the demolition.

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State contractors told town officials noise from the explosion will be comparable to "a single set of fireworks."

Plans to take down the 63-year-old bridge piece by piece changed on Sept. 7, 2018, when workers heard a loud pop come off the steel superstructure, which lies 160 feet south of its successor, the Gov. Mario M. Cuomo Bridge.

Engineers later determined the structure had become structurally unsound and declared it off-limits to workers.

In late December, the Federal Highway Administration approved Tappan Zee Constructors' plan to detonate explosive charges above the water’s surface to take down the old bridge.

In recent days, TZC has been busy briefing the mayors of towns along the Hudson River as well as the environmental group Riverkeeper about its plan.

They were assured the explosion will not be felt by residents who live in towns along the shoreline on either side of the river.

The Piermont Police Department said the village’s pier, which juts out into the river, will be closed to vehicle traffic the morning of the demolition.

“Please do not be alarmed by the explosion,” the department said in a statement posted on its Facebook page. “This process is being done in a safe manner.”

Tarrytown Police Chief John Barbelet said his department will have plenty of officers on hand to coordinate traffic and any crowds of spectators eager to see the old bridge fall.

“The New York State Police has been in contact with us for awhile now. I just left a meeting this morning,” Barbalet said. “They’ve been very accommodating to letting us know what they’re doing and not doing.”

The U.S. Coast Guard has plans to close off a 2,500-foot radius around the demolition site for several hours. Currently, vessel traffic is restricted to a 300-foot channel on the western side of the Cuomo Bridge.

The last bridge in the New York City region to be taken down with explosives was the Kosciuszko Bridge, a link between Brooklyn and Queens, which came down in October 2017.

Controlled Demolition of Maryland, the company that took down the Kosciuszko, will oversee the Tappan Zee Bridge demolition.

Sound and seismic monitors will be stationed “at key locations in Westchester and Rockland counties,” including Tarrytown’s Pierson Park, to gauge “vibrations or air-blasts generated by the demolition,” Tappan Zee Constructors told towns.

State Sen. David Carlucci said Tappan Zee Constructors assured him they had taken every precaution and looked at every scenario before settling on the implosion route.

“I have to go with what the experts are saying," Carlucci said. "They’re promising there will be no impact to the environment.”

The demolition is the latest chapter in the saga of the bridge, one that will likely draw spectators to the Hudson shore. Even a state senator is not immune to the excitement of seeing such a massive structure coming down.

"I"m trying to figure out where to watch it from," Carlucci said.

A demolition timeline

Timeline for Jan. 15 according to Tappan Zee Constructors:

8:30 a.m.: The Hudson River's main navigation channel will be closed for three hours.

10 a.m.: The New York State Thruway/I-87/I-287 will close in both directions from Tarrytown/Sleepy Hollow (Exit 9) to Nyack/South Nyack/US Route 9W (Exit 11) for about 45 minutes while the bridge is taken down.

All traffic will be reopened once the surrounding area is deemed safe.

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Reporter Frank Esposito contributed to this report

Here's a Fact Sheet sent to river town officials hours before it was released to the general public on Friday.