April 2018 - Page 13

Region 1 Spring Assembly – Tarrytown, NY “The New NY Bridge Project” By: Sarah Dinwoodie 2,000 feet from the shore on either side. They continued with the construction of the northbound span and successfully tied into NY Route 287 in South Nyack and Tarrytown. Traffic was redirected from the Tappan Zee Bridge to the northbound span. Presently, the future northbound span is being used for two-way traffic while the Tappan Zee Bridge is demolished and the southbound span is tied into land. Some other interesting facts related to the construction and design:       Photo Credit: https://www.equipmentworld.com/photos-aerial-shots-show-progress-on- tappan-zee-bridge-replacement/ Tying into South Nyack The super crane used during construction has a lifting capacity of 1,800 tons and a boom length of 328 feet. Three floating batch plants were constructed for pouring concrete. They used more than 240,000 cubic yards of concrete. The main span of the bridge is 1,200 feet long and has a 1,042-foot horizontal clearance. The towers are constructed of 8,000psi concrete. 192 stay cables were used, 24 in each tower. Each stay has 36-90 strands and there are 7 wires per strand. The $3.9 billion bridge replacement is one of the largest single design-build contracts for a transportation project in the United States. Noise Being so close to so many residences and businesses, noise was a major concern. The NYSTA replaced windows in many apartment buildings on the Tarrytown shore with noise reducing glass. While hammering the piles, they also had to consider noise levels underwater and potential impacts to aquatic life. “Bubble curtains” were used to reduce hammering noise underwater by 10 decibels. Air is pumped into aluminum rings which produces a ring of bubbles in the water around the pile. Photo Credit: https://www.enr.com/articles/39059-the-new-ny-bridge-over-the-hudson- river-is-halfway-to-finish Bubble Curtain Two cool cats from NH interrupting a wedding photograph session at the Tappan Zee Bridge outlook in Tarrytown, NY.