Start with a reference.

Research record

The detail behind
the study.

Source-linked work for this revision. Reported checks describe the stated model or test; physical qualification and applicability to the current retrofit remain separate.

Four side-level cartridges and eight survey heads, using the original Subfield identity and actual CAD.

34 parts per side. 161 CAD tests passed. Calibration, material/exposure qualification and manufacturing release remain open.

Protected side indicator

Fixed reference and replaceable carrier

Carrier removed / cover hardware retained

Four indicators fitted to the tank

CONCEPT development package for SC-012. Four 34-part units add 136 instances to the complete 2,621-body tank candidate. The source record requires four indicators tied to a common lower-body datum. Each unit has a bonded external support, fixed reference plate, three datum contacts, round/relieved locating pins, a replaceable supplier-level carrier, two survey heads and a protective cover with four captive hand nuts.

Verification: 161 complete CAD tests; 42 part/state/export checks; 15 whole-tank fit/export checks. Sampled motion tests exercise cover withdrawal, captive hardware stops, clamp removal, carrier extraction and all four supplier orientations. Full external extraction envelopes have 3 mm allowance and require an exposed tank side. Nominal survey heads share Z1555. These are geometry checks, not physical calibration or qualified service procedures.

Materials/processes, bond and local shell support, soil/impact/thermal exposure, hardware/thread/torque/locking definitions, manufacturing tolerances, fixture and reference calibration, replacement repeatability and installed-level acceptance remain in development. The shroud is drained and is not an immersion enclosure. Four local readings do not prove absence of global tank distortion or settlement. Earlier tank masters and candidates remain unchanged.

The full 150-scope ledger now records 49 partial concepts, 65 not modeled, 31 deferred and 5 non-geometric scopes. No scope is marked release-ready by this package.