# PATH alignment and core-section follow-up

**Clearance correction:** The later [South corridor review](../path-south-clearance-review/README.md)
supersedes any broad reading of the zero rail-line result below. A solid diagnostic
volume finds one remaining Track 2 conflict at column 301. The rail rereading reduced six conflicts to three; the later [Book 1 corner correction](../south-corner-review/README.md) replaces erroneous corner framing and eight placeholder column sections, leaving one conflict. The railway is unchanged by that later correction.

The SKA12/84 rereading replaces the earlier station and approach controls. The original three wall registration controls and the independent southwest holdout are unchanged. The straight station readings guide the partly obscured transition at the South Tower northeast corner. The southern curves now follow the railway corridors more closely, and Platform A occupies the labeled east-side platform instead of the narrow column strip between tracks 1 and 2.

[Before/after source comparison](south-path-before-after.png) shows the current column envelopes in red and rail centerlines in blue. The full [SKA12 overlay](../foundation-review/PATH-SKA12-overlay.png) also shows the platform bodies. These are comparisons with the original raster drawing, not browser screenshots or a track survey.

The South Tower production-mesh check records **zero rail/member intersections**, down from 16 path/rail/member combinations in the preceding core-transfer pass. The North Tower rail check also passes, and its 12-foot diagnostic corridor no longer flags columns 201/203. No structural workpoint or outer section envelope was moved, removed or cut to obtain that result. The wall, construction tiebacks, foundations and tower joins are retained. The separate core fabrication work changes the interior material of sixteen box sections while retaining their outer dimensions.

The 24 connected rail edges pass the source-hash, enclosure, platform-body clearance and unintended-crossing checks. Shared rail junctions and standard gauge pass the production geometry check. These tests **do not establish vehicle clearance, turnout dimensions or longitudinal grades**. R-65 Section X-X gives the local rail top EL246′6″ and platform EL250; extending the rail elevation through both approaches remains an explicit display projection. The source plan does not resolve every rail line at the obscured transition, and no setting-out precision is claimed.

The diagram from a 1971 Port Authority brochure, reproduced on page 15 of the [January 2004 ERA bulletin](https://erausa.org/pdf/bulletin/2000s/2004/2004-01-bulletin.pdf), corroborates the five-road, three-loop arrangement and distinguishes the older Hudson Terminal tubes from the new terminal loop. It is schematic and was not used as a dimensional registration control.

`baseline.json` freezes the earlier rail paths and structural geometry. `preservation-before.json` and `preservation-after.json` record the rail-only phase; the column full-record hash changes because its clearance notes change. `verification.json` checks the frozen rail-pass workpoints and outer envelopes, allowing the sixteen source-scheduled box interiors, and links the separately verified later corner correction. Plan differences in that report measure the amount of change, not accuracy against a survey.

Reproduce from the workspace root:

```sh
.venv/bin/python tools/build_slurry_wall.py
.venv/bin/python tools/check_path_plan.py
.venv/bin/python tools/build_structural_details.py
node tools/check_south_basement_frame.mjs
node tools/check_slurry_wall.mjs
.venv/bin/python tools/review_path_reconciliation.py
```

The [core-transfer review](../south-core-transfer-review/README.md) covers the sixteen built-up box sections and eight support-joint weld schedules. Interior floor framing and complete joint fabrication are still unfinished.