Inputs
Enter up to five segments. Each segment models a straight run, then an optional bend.
Example data table
Example inputs for a three-bend pull path (illustration only):
| Segment | Straight length | Bend angle | Bend radius |
|---|---|---|---|
| 1 | 25 m | 45° | 0.9 m |
| 2 | 18 m | 90° | 1.2 m |
| 3 | 12 m | 30° | 0.8 m |
Run the calculator to see tension progression and peak sidewall pressure.
Formula used
- Straight-run friction (simplified): T_before = T_in + (w × μ_s × L)
- Bend tension growth (capstan equation): T_after = T_before × e^(μ_b × θ), where θ is in radians
- Sidewall pressure at a bend: SWP = T_before / R
This model is a planning aid. For critical pulls, verify against project standards and manufacturer guidance.
How to use this calculator
- Select your unit system and enter initial tension.
- Enter cable weight per length and friction coefficients.
- Set allowable tension and allowable sidewall pressure limits.
- Add segments in the order the cable travels through the conduit.
- For each segment, enter straight length; add bend angle and radius if present.
- Press Calculate to view segment-by-segment tension and sidewall pressure.
- Use the CSV or PDF buttons to export the latest report.
Plan safe pulls, verify pressure, and protect cable longevity.