Efficient Shallow Underwater UXO Retrieval

Abstract : The objective for this project was to design, build, and demonstrate a semi-automated system to provide an efficient, relatively economical, and safe approach for recovering single unexploded ordnance (UXO) targets in shallow water that are buried too deeply in the sediment layer to be recovered by a diver having access only to hand tools. For the purposes of this project, we assume than an underwater UXO survey, analysis, and preparation of a target list has been completed, and that individual target positions have been reacquired for investigation and marked either with flags (very shallow water) or with weights and floats. After the targets have been marked, the recovery process begins. A work boat is anchored adjacent to the target; it is stabilized by two spuds that are driven into the sediment. A deck crane is used to lower a cylindrical fiberglass shroud onto the target position and a remotely operated water jet/vacuum dredge is used to excavate the sediment from the hole to expose the target. The target is remotely examined using either a TV camera or an imaging sonar system to determine the target's identity and its fuzing. If a supervisory UXO technician determines that the target is safe to recover, it is remotely retrieved using an array of electromagnets.