DfaThe Cat 321D LCR hydraulic excavator is designed for working in space-restricted areas such as close to buildings, road construction, limiting-lane closures or logging roads. The tail swing is 5 feet 6 inches, as compared to the 9 feet on the 320D. The system has been increased to 35,000 kPa, and the pilot pump is independent from the main pumps and controls the linkage.