Video: East Side Access Update 3

On September 20, 2012, a “roadheader” excavating machine broke through the tunnel beneath Northern Boulevard in Queens, NY (CQ28/CQ31). One of the shortest (only 120 feet), but probably most difficult tunnel that has ever been built before. We have been part of that project – the biggest infrastructure project in North America at that time – and successfully supported the owner, MTA CC, with Risk Oversight and Site Risk Reviews on the construction site. With a System Risk Management (System Safety Approach) we additionally reviewed the complex construction processes (by SEM = Sequential Excavation Method) in order to stay within the extreme allowable settlement tolerances for the close-by traffic arteries (Subway lines, Northern Boulevard & Elevated Train) just a few feet above the tunnel. And, therefore, the NYC Subway never had to be stopped …
Video – courtesy of MTA CC and Youtube