Hydraulic Impulse Harvesting in Mass-Confined Stone Passages: Inertial Column Dynamics and Staged Impedance Control

In confined hydraulic systems, water-hammer transients are conventionally treated as destructive pressure events to be suppressed. This paper examines the alternative engineering question: whether such transients can, under specific boundary conditions, be staged into usable mechanical impulse within mass-confined masonry structures. A four-stage mechanism is analysed: diaphragm conversion, cascaded portcullis reflection, inertial water-column displacement, and surface manifold accumulation. The model is tested against surveyed substructure geometries from Old Kingdom pyramid complexes along Egypt’s western escarpment, especially the class of so-called “workhorse” monuments at Saqqara, Abusir, and related sites. The analysis does not assert historical operation as established fact. Rather, it asks whether the fixed architectural boundary conditions are mechanically compatible with staged hydraulic impulse harvesting. Order-of-magnitude calculations show that modest velocity changes in confined water can generate transient pressures far above static head, that granite interfaces can plausibly function as high-impedance reflecting boundaries, and that inclined passage geometries are consistent with inertial water-column behaviour. The result is a mechanically coherent feasibility model in which confined water, gravity, elastic stone boundaries, and manifold chambers could convert irregular pressure events into metered hydraulic force. The broader geological, hydrological, chronological, and network-scale context for this mechanism is developed in Collins (2026).