CLE Engineering was retained by Judlau-DW White to perform pre- and post-construction surveys in support of the Woods Memorial Bridge rehabilitation project. These surveys were done to the specifications dictated by the USACE and the Massachusetts DPW. The project presented several challenging environmental conditions that had to be overcome. The Malden River is a very shallow and narrow water body, shallow water makes full bottom coverage difficult with multibeam systems.
CLE’s experience producing data in shallow water conditions provided data to the extent required by the project. In addition to shallow conditions, the bridge itself makes data gathering difficult. Obstructed views of the sky prevent proper GPS positioning, this is overcome with the use of inertial positioning. Inertial positioning blends GPS positions with positions calculated using vessel accelerations eliminating outages caused by overhead obstructions. Deliverables for the project included obstruction delineation, bathymetric data, and integrated existing and design profiles.