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Calculate preliminary ADSS cable working tension from span, sag, cable weight, wind and ice loading. Estimate RTS/MAT requirement, aramid yarn count and accessory BOM before requesting a project-specific sag-tension chart.
Use this calculator when cable OD, unit weight, span and sag are available. It calculates ice load, wind load, combined load, maximum working tension, estimated RTS/MAT requirement and preliminary aramid yarn count.
Span & Sag Concept
Smaller sag sharply increases working tension. Use the final sag-tension chart for actual pole-line design.
The calculator follows a practical ADSS pre-check path: cable weight + ice load + wind load → combined load → maximum working tension → RTS/MAT estimate → aramid yarn section and count.
| Step | Formula | Meaning | Engineering Note |
|---|---|---|---|
| Ice Load | W2 = 0.00283 × t × (D + t) | Estimated vertical ice load, kg/m | D and t are in mm. Use local ice design data where available. |
| Wind Load | W3 = C × (D + 2t) × V² × α / 16000 | Estimated horizontal wind load, kg/m | When ice exists, projected diameter should use D + 2t. |
| Combined Load | W = √[(W1 + W2)² + W3²] | Vector combined cable loading, kg/m | Vertical load and horizontal wind load are combined as vectors. |
| Working Tension | Nmax = [W×L²/(8f) + W×f] × 9.80665 / 1000 | Maximum working tension, kN | L and f are in meters. This is not the same as RTS. |
| RTS Estimate | RTS_required = Nmax / MAT ratio | Estimated rated tensile strength requirement | Default MAT ratio is 40% of RTS for preliminary screening. |
| Aramid Section | S = Nmax / (E × ε) | Required aramid section, mm² | Nmax in kN, E in GPa, ε as decimal strain. |
| Single Yarn Area | A = dtex / density / 10000 | Single aramid yarn cross-section, mm² | Default density is 1.45 g/cm³. |
| Yarn Count | n = S / A × safety factor | Recommended aramid yarn count | Usually round up to an even number for production symmetry. |
W = √[(W1 + W2)² + W3²] Nmax(kN) = [W×L²/(8f) + W×f] × 9.80665 / 1000 S(mm²) = Nmax(kN) / [E(GPa) × ε] Recommended yarn count = CEILING(S / A × 1.15) Unit note: in this engineering shorthand, 1 kN / 1 GPa = 1 mm², so Nmax in kN and E in GPa give S in mm².
An ADSS sag calculator and ADSS tension calculator are useful for preliminary screening, but span length alone does not define a cable. A reliable ADSS span selection also checks cable weight and diameter, allowable sag, temperature range, support elevation, wind and ice load cases, route angles, electrical environment, fittings and the manufacturer’s verified RTS/MAT limits.
For a level span under uniform load, the parabolic estimate H ≈ wL²/(8f) shows why tension rises with the square of span and falls as sag increases. Treat the result as a pre-check, then use the manufacturer’s sag-tension chart for installation.
ADSS wind load acts horizontally and increases approximately with wind speed squared. ADSS ice load adds vertical weight and increases projected diameter, so the combined resultant load—not either case alone—must be checked.
An ADSS RTS calculation converts the governing working tension into a minimum strength requirement. The selected cable must satisfy the supplier’s stated ADSS MAT EDS limits for short-duration maximum load and long-term everyday service.
| ADSS cable design parameters | Design input | Selection impact |
|---|---|---|
| Geometry | Ruling span, maximum span, support elevations, angles, crossings and clearance | Controls sag, horizontal tension and fitting loads. |
| Cable | Fiber count, diameter, mass, jacket, modulus, thermal expansion and RTS | Defines self-weight, aerodynamic area, elongation and strength. |
| Environment | Wind speed and basis, radial ice, temperature range, altitude, pollution and UV | Defines governing load cases and sheath requirements. |
| Mechanical criteria | Maximum sag, clearance, EDS, MAT, safety factor, creep and installation tension | Determines whether the cable and fittings remain within allowable limits. |
| Electrical and hardware | Line voltage, attachment position, space potential, clamps, dampers and dead ends | Influences AT sheath review, hardware compatibility and vibration control. |
The accessory recommendation is a preliminary BOM direction only. Final quantities depend on pole count, route angle, terminal points, cable reserve points, clamp holding strength and actual cable RTS.
For straight or tangent pole routes, the basic BOM usually includes ADSS suspension sets, pole clamps and related fastening hardware.
For terminal poles, angle poles and crossing spans, ADSS tension sets, guy grips or dead-end grips should be reviewed according to RTS and route angle.
Downlead clamps, cable storage brackets and splice box mounting hardware are normally required at terminal, joint or equipment access points.
For a reliable quotation and sag-tension chart, customers should provide cable physical data, route loading, sag requirement and installation environment.
| Data Required | Why It Matters | Example Format |
|---|---|---|
| Cable OD and unit weight | Used to calculate wind load, ice load and total loading | D = 15 mm, W1 = 0.20 kg/m |
| Span and sag | Directly controls working tension Nmax | Span 600 m, sag 12 m or sag ratio 2% |
| Wind speed and ice thickness | Used for mechanical loading and sag-tension simulation | Wind 30 m/s, ice 5 mm |
| Required RTS / MAT standard | Defines safety margin and structure strength | MAT 40% RTS, 60% RTS tension reference |
| Aramid yarn type | Affects section, yarn count and cable design | 8350 dtex, E = 115 GPa, density 1.45 g/cm³ |
| Power line voltage or space potential | Determines whether AT sheath review is required | 110 kV transmission corridor nearby |
These answers connect the calculator output to cable selection and an actionable ADSS RFQ template. Values are preliminary until the manufacturer checks the actual cable construction and all project load cases.
There is no universal sag value. Preliminary sag is often expressed as a percentage of span; for example, 1–3% is a useful scenario range for comparison, not a final design rule. For a level span with uniform load, H ≈ wL²/(8f), so reducing sag sharply raises horizontal tension. The correct initial and final sag must also preserve ground and conductor clearance at the relevant temperatures while keeping installation tension, EDS and maximum-load tension within the cable and fitting limits. Use this ADSS sag calculator for screening, then obtain the model-specific sag-tension chart.
Enter the cable mass and diameter, span, sag, wind speed and radial ice thickness. Convert the vertical cable-plus-ice load and horizontal wind load into a resultant load w. A level-span parabolic estimate is H ≈ wL²/(8f), with total support tension approximately √[H² + (wL/2)²]. This tool applies the equivalent expression shown in its calculation table. Check every specified temperature and load combination; unequal support elevations, creep and installation conditions require a full sag-tension model.
Wind pressure and ADSS wind load rise approximately with V², so doubling wind speed can produce about four times the aerodynamic load before changes in coefficients are considered. Wind acts horizontally on the projected cable diameter—or the iced diameter D + 2t—and combines vectorially with vertical weight. Higher wind therefore raises resultant loading, support tension, pole load and clamp demand, and may also increase aeolian-vibration risk.
Radial ice adds vertical mass and increases the outside diameter exposed to wind. The cable may therefore need higher RTS, more aramid strength members, greater allowable sag or a shorter permissible span. Ice can also change fitting loads and clearance. Evaluate bare cable, ice-only and the code-required combined wind-and-ice cases instead of adding independent worst cases unless the governing standard requires that combination.
A 100 m span does not determine RTS by itself. Calculate the governing maximum working tension from cable weight, diameter, sag, wind, ice, temperature and support geometry, then divide by the manufacturer-approved MAT/RTS ratio. For example, if the governing tension is 4 kN and MAT is limited to 40% of RTS, the preliminary minimum RTS is 4/0.40 = 10 kN before any additional project margin. Confirm EDS, installation tension, fittings and the supplier’s standard cable rating; do not treat 10 kN as a universal 100 m answer.
An ADSS aramid yarn calculation starts with required tensile section S = T/(Eε), where T is the design tension, E is yarn modulus and ε is allowable working strain. Estimate one yarn’s area from its dtex and density, divide S by that area, apply production and design margin, then round to a balanced lay. Final quantity depends on yarn grade, utilization efficiency, cabling geometry, creep, temperature, target RTS and process controls, so the calculator result is an RFQ estimate rather than a manufacturing prescription.
RTS is rated tensile strength: the declared cable strength reference. MAT is maximum allowable tension: the highest permitted tension for the specified short-duration loading condition, commonly stated as a percentage of RTS. EDS is everyday stress or everyday tension: the long-term normal-condition tension used to control creep, fatigue and vibration exposure. The permitted percentages are cable- and manufacturer-specific and must be stated in the data sheet or project criteria.
Use span as the first filter, then compare the cable’s diameter, mass, RTS, MAT and EDS against the governing sag-tension cases. Include ruling span and maximum individual span, support elevations, route angles, clearances, wind, ice, temperature, electrical space potential and fitting ratings. Short-span, medium-span and long-span product labels are supplier categories, not interchangeable engineering limits; request a sag-tension chart for the exact offered cable.
Provide fiber count and fiber standard; maximum and ruling spans; pole profile, attachment heights and route angles; required clearances and sag limits; wind speed with code, averaging period and height; radial ice; temperature range; altitude; line voltage and attachment position; pollution level; required RTS/MAT/EDS criteria; jacket preference; fittings, dampers and accessories; drum lengths; installation method; and applicable standards. Existing cable diameter or weight should be labeled as fixed requirements or reference values.
A practical ADSS RFQ template should include project location and design code; fiber type/count; route and span schedule; wind, ice and temperature load cases; clearance and sag criteria; RTS, MAT, EDS and safety requirements; line voltage and electrical environment; sheath and marking; compatible suspension/dead-end hardware; test standards and reports; quantities, drum lengths and tolerances; packaging, delivery destination and schedule; plus a request for the cable data sheet, calculation assumptions, sag-tension tables and accessory BOM.
Send your cable OD, cable weight, span, sag, wind, ice, RTS/MAT requirement and pole route data to ZION Communication. Our team can help review ADSS cable structure, aramid yarn configuration, jacket type and accessory BOM.