Compartmentalised pressure-bed support

Established refinement; geometry and hydraulics remain open.

The pressure bed is not one planetary waterbed.

The initial pressure-bed concept risked implying a substantially continuous fluid layer beneath the geology. The revised working model divides support into many bounded pressure volumes. The useful analogy developed in discussion was a pocket-sprung mattress behaving more like memory foam: neighbouring regions participate in supporting a broad load, but individual areas can depress, recover or fail without requiring the entire support field to respond as one unconstrained body.

The analogy describes mechanical behaviour only. The working medium remains fluid and the cells are engineered pressure structures, not literal springs or foam.

Cells localise both movement and failure.

Compartmentation gives the pressure bed a topology. Pressure can be regulated by region, differential geological load can be accommodated locally, and a leak or collapse need not drain the complete support layer. Adjacent cells can continue carrying load while a failed area settles toward its lower structural stops or the rim beneath.

This extends the existing graceful-degradation logic in 600.20:40:01: direct contact remains a degraded but potentially tolerable state, while compartment boundaries limit how rapidly one local loss of support becomes a regional geological event.

Solid cell boundaries create routes through the support layer.

A continuous floating layer makes every vertical connection between inhabited geology and deeper Station structure mechanically awkward: a rigid shaft can become the very direct stress path the pressure bed was introduced to avoid. Compartmentation provides a more plausible arrangement. Service shafts, access routes and other penetrations can pass through or alongside engineered cell boundaries, with local interfaces designed around them rather than forcing arbitrary rigid contacts through an undivided pressure volume.

The exact penetration mechanism remains open. Flexible joints, local collars, sliding interfaces and isolated structural trunks are possibilities to test later, not present specifications.

A failed cell produces a bounded geological defect before it produces a planetary one.

Loss of pressure in one or several cells can produce local settlement, differential loading and seismic movement. Progressive neighbouring failures can enlarge that defect into a valley, basin or sinkhole. Boundary failure or uncontrolled equalisation could defeat the localisation principle and permit a larger cascade; therefore valves, walls and isolation behaviour are safety-critical parts of the eventual engineering solution.

The model deliberately retains uncertainty over how sharply the surface expresses individual cells. Deep geological overburden may distribute loads across many cells, so cell boundaries need not map visibly onto surface geography.

The refinement links geology to structural and maintenance architecture.

Compartment boundaries must transfer load into the rotating structural rim without recreating unacceptable shear. They also provide candidate corridors for pumps, valves, inspection routes and vertical services, tying this model to 600.20:30 primary structure and 600.20:90 locality-based maintenance. The same architecture makes selective isolation and repair conceivable without draining or unloading an enormous continuous region.

This is a current-model refinement, not a retrospective replacement of the earlier record.

600.20:40:01 remains the parent statement of why pressure support exists and how geological contact and subsidence are tolerated. This record captures the later compartmentalisation needed to make that principle more structurally and operationally plausible. The originating design evolution belongs in 400; external hydraulic, hydrostatic-bearing or geotechnical evidence used to test it belongs in 700.