Many formerly used defense sites, base realignment and closure sites, and active ranges have areas that are heavily contaminated with munitions and explosives of concern (MEC) or unexploded ordnance (UXO), range residue, and contaminated soils. These areas include open burning/open detonation (OB/OD) areas, old or current target impact areas, strafing ranges, 40-mm ranges, and small arms ranges with high concentrations of surface and subsurface metallic signatures that would reduce the effectiveness of digital geophysical mapping (DGM). Remediation or maintenance of these sites is hazardous, time-consuming, and expensive. Characterizing these sites with DGM techniques can help to confirm the degree of contamination, but these techniques are currently unable to provide sufficient resolution to properly estimate remediation or maintenance efforts.

The objective of this project was to develop and demonstrate the Range Master for the reliable and cost-effective excavation of ordnance and explosives (OE) from heavily contaminated sites. Phase I of this project provided the primary technology integration of the base carrier and screening system that was manually operated. Phase II incorporated system armoring and remote control components.

The Phase I demonstration was performed at the former Fort Ord, Monterey, California, in February 2004. The manually operated Range Master successfully demonstrated the integration of an excavator and screening unit to safely and effectively excavate heavily contaminated sites and to improve the site’s geophysical conditions. A limitation in the system hydraulics prevented the operator from adjusting the excavation depth in real time. The excavation paddles or the screen shaker motor had to be stopped to adjust depth of cut. The problem was determined to be in the screen shaker motor valve, which was taking excessive flow from the main hydraulic system. This issue was corrected within the control valve, restoring full hydraulic capability to the operator.

The Phase II demonstration was performed at the former Lowry Bombing and Gunnery Range, east of Denver, Colorado, in June 2006. The remotely operated and armored Range Master was mobilized from Maryland to Colorado. The system was set up and safely (remotely) excavated four of the intended five 50 x 50 m grids just east of the Bomb Target #2 target center. This live site demonstration, although less effective than the Phase I demonstration, demonstrated that the remote excavation of heavily contaminated UXO sites is possible. The “before” and “after” DGM results reflected a lack of expertise in maintaining a uniform depth of cut. Although the remote control operation was successfully demonstrated, effective excavation and sifting of the top 12 inches of soil was not. The Range Master did, however, remove and expose 2,133 ordnance-related metal pieces, totaling approximately 508 pounds.

A robust, remotely operated UXO excavation system such as the Range Master, with replaceable armor, chains, paddles, and screens, could provide a cost-effective tool to (1) remediate heavily contaminated UXO sites to depths of 12 inches below ground surface, (2) clear range clutter and UXO for identification and disposal in a single pass, (3) remove contaminated soils for treatment or to perform deeper remote clearance operations, note that additional design and modifications are required to hold and carry excavated soils, and (4) prepare and optimize heavily contaminated UXO sites for deeper and more effective DGM characterization and remediation. The ability to remotely screen and observe excavated objects and suspected UXO items for disposal would improve the efficiency and safety of near-surface “Mag and Dig” or mechanical sifting operations.

The operational limitations of the Range Master include wet and heavy soils (any soil that cannot be effectively power-sifted), excessive vegetation, terrain variations, and slopes greater than 30 degrees.