Underhull Material Transport Rig: Aircraft Carrier Maintenance Processes

The clearance under a ship in the Newport News Shipbuilding dry dock is approximately 62 inches. As a result, workers are either crouched or hunched over as they carry materials and equipment underneath the ship to their work zone. This can cause physical strain on workers’ bodies, leading to safety and health problems. This design project solves the problem by creating a transport system that uses a cart suspended from two trolleys that ride on a track attached to the bottom of the hull. A working prototype was built, demonstrated, and tested. This prototype cart maneuvered through a straight and a 90 degree curved section of rail. Scaffolding was built to simulate the bottom of the ship\u27s hull. The main constraints for this system included - setup time, ground clearance, and load capacity. The setup time could not exceed 8 hours, the lowest point of the system must be at least two feet off the ground, and it must be able to carry a load of 150 lbs, with a factor of safety of 2.5. The approach taken was to suspend the system from the bottom of the hull. Design decisions included the type of track or rail, the type of trolley, the cart design, the connection of the cart to the trolley, and cart stabilization methods. A successful prototype of this design was built and tested. The prototype meets all of the design specifications. Two improvements that could be made to the design include a way to move the cart without manually pushing it and a way to switch the cart between different tracks. This project impacts Newport News Shipbuilding by creating a safe and efficient way to transport materials while under the hull of a ship.https://scholarscompass.vcu.edu/capstone/1127/thumbnail.jp