By Luke Carothers

McCarthy Building Companies recently completed work on a $36 million Topgolf project in El Segundo, California.  McCarthy, a leading general contractor, completed this project thanks in large part to the use of drone mapping.  The project team utilized drone technology to capture the existing site for earthwork cut and fill analysis in reference to its final design grading model–ultimately enabling them to build out the site per the design plans.  The project site was large, encompassing 12 acres and a 3-story 60,000 square foot building, but many of the project’s time consuming processes were shortened using drone technology.

Although this isn’t the first project in which McCarthy’s team leveraged drone technology, it demonstrates how the technology has moved from a niche tool for specific tasks to a part of standard operations for the firm.  McCarthy began using drones in various capacities a few years ago, but they began being adopted as the standard around 2019.  Jared Miller, Director of Operations for McCarthy’s Mapping Group, says that this was part of a larger effort to standardize practices across the company.  McCarthy’s Mapping Group focuses on mitigating risk from subsurface utilities, and has recently expanded its capacities with drone-based lidar and photogrammetry.    According to Miller, prior to this push for standardization, individual pockets of the company had been developing innovative solutions using drone technology.  Recognizing the potential for the technology, the firm began implementing these practices on every project by using drones on the majority of their projects.

For many firms and project owners, the initial investment in drone technology can be steep.  The cost of purchasing a drone and training someone to fly it properly or even hiring a professional drone pilot can be in the tens of thousands of dollars.  Despite the initial investment necessary for deploying drones in this capacity, Nic Maroun notes that this is repaid several times over throughout the course of construction.  Maroun, a Senior MEP Project Engineer at McCarthy, speaks to the capacity of drone technology to produce things like drone-stitched models that are “invaluable” when creating plans and overlaying them with BIM models.  This allows the team to see both the real world overlaid with ideal utility mapping, allowing them to identify and mitigate potential problem areas.  

Now, drone technology is a part of the majority of McCarthy projects in some capacity.  Trevan Thompson, who worked on the El Segundo Topgolf project, says that drones have become a part of McCarthy’s standard of care.  For projects like the one in El Segundo, drones are instrumental in improving documentation, logistics, and cut/fill analysis among others.  Thompson, a Senior VDC Engineer with McCarthy, was responsible for BIM coordination with the MEP systems as well as conducting several drone flights for documentation, logistics, and planning on the Topgolf Project. Thompson points out that drones are especially useful for large area projects such as the one in El Segundo.   

Depending on where a project is located, different restrictions have to be taken into account to maximize the effectiveness of drone technology and prevent any delays.  In the United States, these restrictions are set by the FAA.  The project in El Segundo was partially limited in terms of the height at which the drones could fly due to its proximity to Los Angeles International Airport (LAX).  This was complicated by the design of the facility itself, which necessitated a series of high metal poles around the perimeter of the project which support the netting.  Thompson says they had to find the “sweet zone” to where they would not violate FAA restrictions and also not damage the drone by colliding with one of the poles.  

Another area where drones have proven effective is grading.  Maroun points out that drones are “excellent” for performing cut/fill analysis. Once this area was established on the El Segundo project, the drones flew over the site, taking thousands of images that are stitched into an orthomosaic map by a third party software.  This map also contains a point cloud as well as a 3D mesh of the site which is then used for cut/fill analysis and other processes.    On another recent project, drones were used to perform a cut/fill analysis, and the data showed that the grading subcontractor had underestimated the material to be removed by a great deal.  By leveraging drone technology, McCarthy’s team identified a potential issue before it could manifest, saving time and money down the project timeline.  In other cases, these orthomosaic maps can be overlaid with civil sheets to verify, in real time, whether things like sewer lines are being dug in the right places.  

Using drones, the team at McCarthy completed the El Segundo Topgolf Project on time and on budget.  Opened on April 11, 2022, the El Segundo Topgolf not only appeals to those seeking recreation with 102 outdoor hitting bays, but also to those seeking socialization with a restaurant and sports bar.  This project demonstrates the next step of drone technology within the AEC industry, moving from small pockets of innovation to full scale use and implementation.


Luke Carothers is the Editor for Civil + Structural Engineer Media. If you want us to cover your project or want to feature your own article, he can be reached at lcarothers@zweiggroup.com.  

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