The 6700 Positive Displacement (PD) Workhead is a ballast compaction unit, using 16 paddlestyle tamping blades (2 per head). The workheads are positioned hydraulically to precise depths using position sensors located on each head to provide position feedback to the Jupiter II Control System. The workheads can be used in a normal production-mode of operation on straight-line tangent track or can be operator positioned side-ways hydraulically (swung in/out to clear track obstructions as needed) to accommodate switch work tamping in turn-outs and crossovers.

The 6700’s positive displacement workhead uses a dual-tool, oscillating action to help auger through and displace cemented ballast to get below tie depth. The squeeze/vibration action of the paddles helps life (‘nip’) the tie against the bottom of rail and compacts the ballast under the tie currently being tamped. The positive displacement of the PD workhead paddles is approximately .5 in. and oscillates at approximately 3200 cycles per minute.