Cable pulling tension equations
A straight section is followed by an equivalent bend using the capstan relationship.
Tstraight = T0 + μwLgTout = Tstraight × e^(μθ)SWP = Tout/rwhere:
- μ
- Coefficient of friction
- w
- Cable mass per unit length[kg/m]
- θ
- Bend angle[rad]
- r
- Bend radius[m]
Real routes require segment-by-segment calculation in pulling direction.
How to use the Cable Pulling Tension Calculator
Estimate straight-section pulling tension, capstan tension after a bend, sidewall pressure, and allowable-tension utilization for a simplified cable pull. Start by choosing the operating mode, then enter values from nameplates, measurements, or project documents in the units shown. The result updates immediately and keeps intermediate quantities visible for review.
- Confirm the system and calculation mode.
- Enter measured or manufacturer-rated values.
- Review the primary result and intermediate metrics.
- Continue with the related protection or equipment-selection checks.
Calculation method and validation
The equations and symbol definitions above show the complete calculation basis. Inputs are checked before calculation so zero, negative, incompatible, or physically impossible combinations are flagged instead of silently producing a misleading result.
How to interpret the result
Use the main result as a starting value and read every supporting metric. One straight section followed by one equivalent bend Uniform cable weight and friction Bend angle θ is in radians in the capstan equation A passing or recommended result means the entered mathematical conditions are satisfied; it does not certify the complete installation or a particular product combination.
- One straight section followed by one equivalent bend
- Uniform cable weight and friction
- Bend angle θ is in radians in the capstan equation
Selection limits and next checks
Preliminary engineering estimate only. Verify the final design against the current applicable standard, local rules, manufacturer data, and project conditions. Real routes require segment-by-segment calculation in pulling direction. Use cable and pulling-eye manufacturer limits, conduit geometry, lubrication, jam ratio, and minimum bend radius. Compare the output with the current applicable standard, local rules, exact VIOX product datasheet, environmental conditions, protection coordination, and the engineer's project requirements before procurement or installation.
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Assumptions
- One straight section followed by one equivalent bend
- Uniform cable weight and friction
- Bend angle θ is in radians in the capstan equation
Important Warnings
- Preliminary engineering estimate only. Verify the final design against the current applicable standard, local rules, manufacturer data, and project conditions.
- Real routes require segment-by-segment calculation in pulling direction.
- Use cable and pulling-eye manufacturer limits, conduit geometry, lubrication, jam ratio, and minimum bend radius.