Pennichuck Water Works
Scanning & Modeling, Snow Station
Challenge: The engineering team at Pennichuck had a challenge before them; to increase water pumping capacity by 50% at a pump station that was already packed full of equipment. Adding to the challenge, the pump station was in a beautiful, historic building (originally constructed in 1893) that had recently been meticulously renovated at significant expense.
The team at Pennichuck knew from experience that this type of equipment is very difficult to measure accurately with traditional means, and that a cumulative error of ¼” in measurements of a group of components can cause big headaches later if the new equipment cannot fit in the available space. They wanted, therefore, to use the latest technology to ensure that the “existing conditions” documentation their new designs would be built upon was as accurate as possible.
Solution: Pennichuck hired Doucet Survey to perform high-definition 3D laser scanning and modeling of the pump station interior and exterior. The objective was to provide CAD files that very accurately depicted the geometry of the various generations of pipes, pumps, valves, motors, and electrical conduits as well as the various curved timber beams overhead, etc. These files would form the foundation of a building information model (BIM) of the facility, so Pennichuck wanted to have the elevations referenced to NAVD-88, and to be able to geo-reference the model on NH State Plane Coordinates.
The Doucet Survey team ran a control survey around and through the building, setting control points that would be used to accurately register the multiple point clouds together. They ran differential levels from a nearby benchmark disk and performed multiple GPS observations on their survey baseline using an RTK network. The Doucet team used our Leica laser scanner to survey the interior and exterior building spaces over a period of two days, and then registered the multiple point clouds together onto the survey control using Leica Cyclone software. The single, unified point cloud was exported to Autodesk Recap software, and then the modeling began.
The Doucet team used Autodesk Revit 2017 to model each individual component seen in the point cloud. The majority of components were modeled from scratch, as the “OOTB” family components in Revit or those available for download did not accurately represent the type and vintage of components at the pump station. Finally, the compilation of models for the various components, walls, floors, twisted and bowed timbers, etc. were exported from Revit to AutoCAD 3D solids, and those files were given to Pennichuck along with 2D plan & profile views generated from the 3D CAD files. Pennichuck plans to use these files to design upgrades to the pumping station with precision that will reduce field complications during construction and installation.
The team at Doucet Survey thoroughly enjoys using the latest technology to help our clients produce better designs by putting better information to use up front.