Review requested: railway g-envelope screening

[carstenartur]

Objective

Review the first-order railway g-envelope screening logic and identify where the document is too optimistic, too conservative, or missing railway-dynamics constraints.

This issue is not about selecting railway as the architecture. It is about whether the railway section gives external readers a defensible order-of-magnitude interpretation.

Entry documents

• docs/engineering/railway-g-envelope.md
• docs/engineering/railway-platform.md
• docs/engineering/tilting-train-and-cant-limits.md
• calculations/railway_g_envelope.py
• docs/architecture-trade-study.md

Review questions

1. Are the approximate g-corridors for conventional rail, special rail, and non-standard systems plausible as screening language?
2. Are track cant, cant deficiency, carbody tilt, wheel unloading, stopped-state behaviour, and clearance treated correctly?
3. Is the statement that 1.10 g+ is outside ordinary railway cant/tilt logic defensible?
4. Which standards, textbooks, or simulation methods should be referenced next?
5. Is the current wording clear enough for non-railway reviewers?
6. Which railway claims should be weakened before outreach?

Relevant expertise

• railway dynamics
• vehicle-track interaction
• tilting trains
• ride quality
• guideway systems
• safety engineering
• mechanical systems

Expected output

A revised railway screening section and a list of required next calculations or external references.

Definition of done

• Screening g-ranges are accepted, corrected, or replaced.
• Missing railway-dynamics constraints are listed.
• Required next model scope is defined.
• Document language is updated to avoid overstating railway feasibility.