The objective of the project is to design, test and validate an unexploded ordnance (UXO) target handling and sediment fluidization claw that can effectively deploy UXO targets up to 24” deep in sand and mud seafloor sediments with minimal disturbance to the sediment structure and can then be integrated into a bottom lander used to deploy UXOs and clutter targets at SERDP test ranges. A second goal is to present a system design and cost estimate for a complete bottom lander once the fluidization claw has been demonstrated.

Technical Approach

The system would employ a linearly actuated claw that would provide two functions: to handle the target to be deployed and fluidize the surrounding sediment using integrated seawater jets along its outside surfaces. By fluidizing the seafloor sediments, the claw can insert targets into the seafloor without first excavating the sediment. The project team envisions this system at the center of a ship-operated bottom lander used to deploy UXO and clutter targets at future test ranges. All other subsystems of the envisioned bottom lander have been developed for acoustics research projects at the University of Washington Applied Physics Laboratory (APL) and are field proven, allowing for a low risk path to complete the system once the fluidization claw has been demonstrated. 


The fluidization system is itself based on previous APL development efforts. The project team has developed a successful sediment fluidization system for inserting acoustic probes 3 meters (m) deep within sand and mud sediments in up to 100 m water depth, with minimal sediment disturbance. Because the geometry and handling issues associated with UXOs provides a new engineering challenge, the project team plans to develop and validate this subsystem before proposing a full UXO and clutter deployment system.

  • Claw,

  • Fluidization,