Research — Auto Demo · Precomputed (draft, unvalidated)

Duct bank: one feeder becomes four — auto

No controls here: six short stories play on their own. A bank grows from one conduit to four and its ampacity falls below the first feeder. Wider spacing changes the trench but not the number. Deeper burial makes it worse; a lower soil resistivity or separate banks fix it. Then concrete sizing and a crowded conduit. Use Pause, or the story and step buttons, to stop on any frame.

Story

Duct bank · end view of the trench, bank and conduits

Bank ampacity vs feeder loads

Ampacity by bank shape · same cable, soil, burial and ambient

Every check at this step · the controlling row is highlighted

Rule column: the citation the data file gives for each check. None of these limits is checked against a published standard here.

How the checks read it

Every check · the problem, the change, the fix

Required values are the functions' own defaults for these cables, read from the data file: the fill limits and the grouping source have no checked citation. A row marked value is a number the function returns with no verdict. The feeder row is the exporter's own comparison against invented loads.

Precomputed results:every verdict, required value and margin on this page was computed by the real Python harness at export time and is played back from a data file. The page runs no harness logic and holds no standards tables, and it never interpolates between exported values. Not a live API call. Precomputed by the real functions design_duct_bank_layout, calculate_conduit_fill, calculate_duct_bank_ampacity, calculate_trench_dimensions and calculate_concrete_encasement in uvm-agent-harness (commit a267697), plus calculate_cable_ampacity once per cable for the reference-condition base ampacity the bank function takes as its input; the 41 related tests are internal self-consistency checks, not a standards check. This is draft, inherited code: the harness's own validation notes call it a starting inventory, the calculation services have had no expert review, and standards ingestion has not started. The grouping factors are secondary-sourced and unchecked against the standard text; the fill limits, conduit inner diameters, cable diameters and the jam band are constants in the code; the soil, ambient and depth factors are square-root forms with no source. The feeder loads and the 5 percent tight band are invented by the exporter (provenance demo logic). Treating separate banks as thermally independent is a demo assumption: the harness has no inter-bank model. Concrete volume is the whole bank envelope (conduit volume is not subtracted), the run length of 500 ft is illustrative, and the harness prints a unit cost that is unsourced and not shown. Domain maturity, quoted from the domain page: 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.Real functions this maps to:design_duct_bank_layout, calculate_conduit_fill, calculate_duct_bank_ampacity, calculate_trench_dimensions, calculate_concrete_encasement.Not modeled: heat flow between conduits or between banks, spacing as an input to ampacity (the function has none), encasement as an input to ampacity, a thermal-backfill model (a lower soil resistivity number is the only stand-in), cooler ground at depth, per-conduit ampacity (one number covers the whole bank), cable pulling, vault sizing, and any standards-based limit. The conduit trade size is used as the drawn diameter, the conduit wall is drawn at a fixed width so it can be seen, and the street, soil and trench art are a fixed illustrative backdrop.See also:Duct bank, interactive with free play · Cable pull, vault to vault · Conduit fill