Research — Illustrative (draft, unvalidated)

Insulator swing vs wind

Pick wind pressure, line angle, tension and vertical span for a suspension string, and watch it swing toward the structure. Enter your own allowable swing angle to see the vertical span that would hold it. The bulletin's TH-10 161 kV cases are one click away as presets.

Elevation looking along the line · suspension string swinging toward the structure (schematic)

Bulletin TH-10 161 kV cases · sets tension, wind and limit

Wind pressure

Line angle

Conductor tension

Vertical (weight) span

Horizontal (wind) span

Allowable swing angle · yours to enter

degrees from vertical

The bulletin's TH-10 example values (Table 7-2): 16.4° no wind, 53.2° moderate wind, 77.7° high wind. Your structure's limit may differ.

Insulator swing

Swing angle

Vertical span for the entered limit

Against your limit

How the check read it

    Client-side port:the logic and table in this page are a TypeScript port of the harness function, checked against values exported from the Python tests. Not a live API call. Domain maturity, quoted from the research page: “Schema draft, unvalidated. No structural or transmission-line PE has reviewed it. Insulator swing, pole capacity, crossarm span and guying are checked against the bulletin’s worked examples; ROW width and galloping are formula-consistency only.” The harness returns computed values, never pass/fail verdicts, and so does this page. Reference points from the bulletin's worked example (for example 315.89 ft at 1° and 390.40 ft at 2° for 53.2°, 6,244 lb, 800 ft span, 135 lb string) are labeled in the golden data and agree with the Python within the tolerance its tests use (±2 ft); they are not pass/fail claims.Real functions this maps to:insulator_swing_angle_deg, required_vertical_span_ft, conductor_wind_load_per_foot.Not modeled: the clearance table the swing is meant to be compared against (Bulletin Table 7-1), the structure geometry, and the allowable swing limit, which is YOURS to enter: the 16.4°, 53.2° and 77.7° values are shown only as the bulletin's TH-10 example values (Table 7-2, 161 kV, 10 insulators). Conductor and string are fixed to the worked example's 795 kcmil 26/7 ACSR (1.108 in, 1.0940 lb/ft) and a 135 lb string. Wind is assumed blowing toward the structure; temperature, ice and span sag are not modeled. The drawing is schematic: only the angle and force ratio are computed.See also:Insulator swing, auto sweep · Pole groundline moment, interactive