This research established a protocol for sample preparation and testing between a large suction water characteristic curve (SWCC) device and a large-scale direct shear (LSDS) device using clean ballast and fouling material collected from mainline track. This allowed for comparisons of strength and volumetric behavior at volumetric water contents from the SWCCs. Preliminary results indicate the characteristics of the fouling material control the unsaturated characteristics of fouled ballast. Meaningful changes in peak stress were observed at different volumetric water contents in 5 percent fouled specimens, where the water contents were bound by the SWCC measurements.