Underground vault and conduit engineering as deterministic tools — ported, not yet expert-reviewed.

Interactive demos

• Duct bank: one feeder becomes four →Grow a duct bank one conduit at a time: the whole bank's derated ampacity sinks through the feeders while every conduit fill stays put. Wider spacing does not help, deeper burial makes it worse, splitting the bank or lower soil resistivity fixes it. Draft inherited code, unvalidated.Auto ▶
• Vault sizing and cable training →A catalog vault cutaway in feet next to a true-scale plan: conduits enter ports, cable trains at its minimum bend radius, and a splice or switch needs a clear working square. The sizing function's own pick can fail the working-clearance function, and at 34.5 kV with a 3 ft switch no catalog vault passes. Five stories plus free play. Harness catalog, not a standard; draft, unvalidated.Auto ▶
• Cable pull, vault to vault →Pull cable vault to vault: tension climbs at each bend, a sidewall-pressure arc turns red, and reversing the pull, a bigger radius or an intermediate vault fixes it. Draft inherited code, unvalidated.Auto ▶
• Conduit fill →NEC Chapter 9 fill on a true-scale conduit cross-section, with 53 / 31 / 40 percent limits and a three-cable jam check.Auto ▶

Harnesses in action

Scripted chat-and-viewer examples where this domain's harness is one of the tools. Illustrative, not live sessions.

• In the application: approved fixes land in the open design file →Illustrative, scriptedAfter a person approves a fix, the harness makes the change inside the open design file through the design application’s own automation interface, in four scripted sessions: an overhead pole, an underground pad-mount, a substation drawing and a datacenter plant. Each shows what that application offers to reverse the change, including one case where it offers none. A model label can be switched without changing a single tool call.
• Grid to rack: one design, six harnesses →Illustrative, scriptedA grid-fed datacenter reviewed stage by stage: transmission tap line, substation bus scheme and fence, duct bank, hall power path, service-gear fault current against its interrupting rating, and liquid cooling. Each stage hands a result to the next.

All harness demos →

What it can do

• calculate_conduit_fill

  NEC Chapter 9 fill percentage for cables in a conduit, with pass/fail against the allowed limit.

• calculate_pulling_tension

  Cumulative cable pulling tension through bends and straight sections.

• calculate_cable_ampacity

  Neher-McGrath ampacity with soil resistivity, burial depth, grouping and temperature corrections.

• recommend_vault_size

  Selects an ANSI vault from conduit count and equipment needs.

• calculate_arc_flash_energy

  IEEE 1584 arc flash energy, hazard category and PPE.

• get_vault_topology

  Derives vault adjacency grouped by connected component, fresh per request.

• propose_underground_fix

  For a failing jam-ratio, cable fault-withstand, concentric-neutral or clearance check, the next conduit or cable size or the vault dimension that passes the same check when re-run, with side effects such as changed conduit fill. Fault current, voltage and materials are never changed.

A worked case

Where this stands

Starting inventory, not a completed review. The calculation services were inherited as live code that predates the review process and have had no expert sign-off; ingestion of the NEC standards text has not started.

Open questions

• First standards ingestion pass (NEC Chapter 9 conduit fill) has not started, and no reviewer is assigned.
• No lineage service is deployed, so publishing a vault to the grid graph returns “not configured”.
• The pole-to-vault riser transition is not yet derived.