Tulloch was contracted by St. Mary’s River Bridge Company to complete a pre-engineering survey of the existing and proposed Sault Ste. Marie International Bridge Plaza. The Plaza is undergoing a major redevelopment based on a Master Plan that was approved in August 2008. The work required capturing all existing detail within the site boundary and compiling the cadastral fabric to create one overall base plan that will be used for design.

Horizontal project control was set on site using four Locus static GPS receivers. The data was processed and adjusted using the least squares method. The result of the adjustment calculates exact coordinate values for the measured points in order to create a perfectly closed network. The errors between the actual and adjusted vectors are analyzed, and if they are all within acceptable tolerance then the adjustment was successful.

First order elevations were transferred from primary vertical bench marks to local benchmarks by means of fly leveling. This process was completed during the first day in the field. Once project control was set, verified, and checked, detail collection began. The process of setting and verifying project control at the beginning of the job is very important to ensure optimal integration, and consistency with incoming data. The final product will be a 3-dimensional base plan.