With creative use of laser scanning, Alberici Constructors has shaved four weeks off its schedule to install two 120-ton steel vertical-lift gates that are part of a $165-million complex designed to block storm surge from entering the eastern flank of New Orleans.
Mitch Collins, a surveyor and project adviser for St. Louis-based Alberici, used a $150,000 Leica GeoSystems Scan Station to scan both the gates and the slots in their vertical concrete-tower abutments to make sure everything was aligned and that the gates would slip in within a strict, half-inch tolerance. This assurance— achieved with laser scanning—made it possible for the contractor to install the stainless-steel rails that support the gates' wheels and secondary concrete before the gates were on-site.