NYC's MTA Outlines New Blasting Procedures
Debris from a blast on Aug. 21 damaged some nearby buildings. The transit agency has announced it will hire an independent safety consultant to review all blasting and safety procedures.
The $4.45 billion Second Avenue Subway project in Manhattan is one of the largest construction projects in the country, and the agency building it is adding an extra measure of safety. The Metropolitan Transit Authority recently announced it will hire an independent safety consultant to review all blasting and safety procedures and will take additional steps to ensure blasting is done safely.
An Aug. 21 blast that caused damage to nearby buildings is the reason for the actions. The blast was to remove rock outcrops at the top of a future escalator.
MTA announced that holes drilled for that shaft for the loading of explosives normally would have been done vertically, allowing the blast pressure to dissipate horizontally, but the outcrops being blasted Aug. 21 had to be drilled diagonally. "The decking lifted and allowed rock to be propelled into the air and onto the street," according to the agency's online account. "In reviewing yesterday's incident, we determined that the method used to keep the decking in place above the blast area was inadequate for this type of blast."
The agency said it is evaluating these steps so the problem won't recur:
- An independent safety consultant will be hired to review all the blasting and safety procedures to ensure the community is protected.
- The contractor, SSK, is conducting an in-depth review of the decking systems that will include anchoring the protective steel panels to prevent rock from exiting the shaft.
- The perimeter around the blasting area will be increased, keeping pedestrians farther from the site during a blast.
- Contractors will add protective mats when they expect the blast pressure to be vertical rather than horizontal.
"We are grateful that no one was injured as a result of yesterday's blast," the agency's release states. "We also want to apologize to residents, business owners, and their employees along the Second Avenue corridor who have already had to endure more than their fair share of inconvenience during this project. The MTA will continue to hold contractors and everyone associated with MTACC's projects to an extremely high standard. While we are working tirelessly to do what many call 'an impossible task' — building a subway in one of the most densely populated neighborhoods in the largest city in America — we will continue to make every effort to be a good neighbor."
The Second Avenue Subway's first phase is scheduled to be completed in December 2016. It will reduce overcrowding and delays on the Lexington Avenue line and will serve 213,000 daily riders, according to MTA.