Plan safe spans with clear tension and sag. Check stress limits before stringing begins today. Use advanced temperature solving for reliable final settings always.
| Case | Span (m) | Weight | Inputs | Key outputs |
|---|---|---|---|---|
| Sag-based | 250 | 12.5 N/m | Sag = 7.5 m | H ≈ 13,021 N, Support T ≈ 13,501 N |
| Temperature-adjusted | 250 | 12.5 N/m | Hi = 18,000 N, Ti = 20°C, Tf = 55°C | Hf solves, Sag increases with temperature rise |
Conductor tension governs clearance, pole loading, and long‑term reliability. During stringing, crews set a target tension so the resulting sag meets drawing requirements under the selected load case. Low tension can violate minimum clearance, while excessive tension can damage strands, dead‑ends, or supporting members. A recorded calculation also supports inspection and future troubleshooting.
Span length and resultant weight per meter establish the basic geometry and vertical reactions. Weight should represent the governing condition, including self‑weight and any specified ice or equivalent vertical component. In sag mode, the mid‑span sag directly controls horizontal tension using the parabolic approximation. Use measured spans and consistent units to reduce field error.
Conductor length increases with temperature, typically increasing sag and reducing tension when supports remain fixed. The temperature mode estimates final horizontal tension by matching the geometric length change with elastic strain and thermal strain. Enter modulus, area, and expansion coefficient for the specific conductor, not a generic material value. Check both the hottest and coldest design temperatures. For temperature studies, use the same span and loading so changes reflect only material behavior and weather conditions.
Support tension is the resultant of horizontal and vertical components and is the most relevant value for hardware and structure checks. Calculated stress uses support tension divided by area, helping compare to allowable working levels. If rated tensile strength is provided, the percent value gives a quick safety screen for stringing limits. Always confirm clearances at mid‑span and near attachments.
Start with the design criteria, then run a sag case for the planned condition and a temperature case for the expected daily range. Adjust inputs for special crossings, long spans, or heavy loading zones. After calculations, document temperature, instrument readings, and the final settings applied on site. Export the CSV or PDF and attach it to daily reports for traceable construction records.
Horizontal tension is the mid‑span component that mainly controls sag. Support tension is higher because it also includes the vertical reaction from the conductor weight.
Enter the resultant weight per meter for the condition you are checking. Use self‑weight plus any specified ice and the vertical component of wind, converted into consistent units.
Use temperature mode when you know the initial tension at a measured temperature and want an estimated final tension and sag at another temperature using elastic and thermal strain.
The sag relation used is a parabolic approximation that works well for typical distribution and transmission spans with moderate sag. For long spans or high precision work, confirm with full catenary or utility charts.
Percent of rated strength compares calculated support tension to the rated tensile strength you provide. Many utilities specify allowable working ranges; if your percent is high, reduce tension or recheck assumptions.
You can, but you must input the correct combined area, modulus assumption, and resultant weight for the bundle. If spacers or dampers affect behavior, follow the project specification or manufacturer guidance.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.