College - Author 1
College of Engineering
Department - Author 1
Mechanical Engineering Department
Degree Name - Author 1
BS in Mechanical Engineering
College - Author 2
College of Engineering
Department - Author 2
Mechanical Engineering Department
Degree - Author 2
BS in Mechanical Engineering
College - Author 3
College of Engineering
Department - Author 3
Mechanical Engineering Department
Degree - Author 3
BS in Mechanical Engineering
College - Author 4
College of Engineering
Department - Author 4
Mechanical Engineering Department
Degree - Author 4
BS in Mechanical Engineering
Date
12-2025
Primary Advisor
Hyeonik Song, College of Engineering, Mechanical Engineering Department
Abstract/Summary
The goal of this report is to showcase how our final Core Sampler design and prototype address the needs of Navy Divers. Geotechnical equipment for Navy divers has not been updated since the early to mid-1980s, resulting in imprecise and outdated sampling methods. The primary purpose of this project is to enhance, modernize, and redesign a tool to collect a minimally disturbed core sample of the seabed for geotechnical evaluation. This report presents the full development of our project from concept to verification and final outcomes. It begins with the statement of disclaimer, followed by a four-panel executive summary and this overview. The document then provides a concise concept description of our solution, a detailed implementation section outlining procurement, fabrication, and assembly, and a design verification section describing test procedures, performance results, and supporting data. The report ends with conclusions and proposes the next steps. Comprehensive supporting information is included in the appendices, such as references, budget, user manual, risk assessment, test results, and design analysis or code.
To address this problem, our team created a decoupled auger core sampler that improves sample quality and ease of use for the divers. This design features a decoupled inner cylinder driven down by an outer cylinder with auger blades powered by a NEMO underwater drill. Constructed primarily out of aluminum with brass bearings, the design can withstand the high pressure and saltwater conditions. By utilizing the NEMO drill and decoupling the collection cylinder, this design modernizes the process by minimizing the physical exertion on the divers and providing a minimally disturbed sample.
Throughout the development process, our team created multiple iterations to develop and refine the key features of the Core Sampler design. Due to material procurement limitations, our team developed a preliminary 3D printed prototype to demonstrate the decoupled system and evaluate its feasibility. This provided valuable insight into system performance and improvement needs. An additional prototype was developed to showcase the validity of a power drill-powered auger. For this, we tested a commercially available drill to confirm its effectiveness in saturated sediment and sand. These results, combined with guidance from our sponsors and mentors, informed the final design. The final verification prototype shows how the decoupled cylinder works as intended and improves the ease of use for the divers.
The following sections include a detailed concept description, the implementation including procurement, manufacturing and assembly, and the design verification displaying how the tool meets several criteria and how it could be improved. The report concludes with some final statements about the tool, recommendations to improve the tool, and appendices which provide supporting analysis and documentation.
URL: https://digitalcommons.calpoly.edu/mesp/880