IS 2713 : 2000Tubular Steel Poles for Overhead Power Lines

IS 2713:2000 is the specification for tubular steel poles for overhead power lines (the series covers the pole tubes, dimensions and the design/loading basis). It governs the swaged/stepped tubular steel poles used for LT/HT distribution lines, street lighting, and small power supports — the everyday steel pole on Indian roads and feeder networks.

It is read with the line, loading and protection stack:

• IS 875 Part 3 — wind loads (the dominant design action on a pole)
• IS 800 — general steel construction (member/foundation design principles)
• IS 2629 / IS 4759 — hot-dip galvanizing (poles are galvanized for life)
• IS 5613 (parts) — design, installation and maintenance of overhead power lines

IS 2713 poles are stepped tubular sections built up from standard tube lengths swaged together, designated by an overall service load / working load at the tip and length (the familiar 410-SP / 410-GP-type designations cover specific tip loads and heights).

The engineering inputs:

• Tip / transverse load — the resultant of wind on conductors and on the pole, plus any unbalanced conductor tension, applied near the top
• Wind load to IS 875 Part 3 on the projected area of pole and conductors for the site wind zone
• Permissible deflection at working load (the pole must not deflect excessively or take permanent set)
• Planting depth — typically about 1/6 of the pole length in a properly compacted/concreted foundation

The pole is selected so its working tip-load capacity ≥ the computed design tip load, with the specified factor and deflection limits, and it is hot-dip galvanized for corrosion life.

Brief: 8 m tubular pole for an LT line, coastal/high-wind area.

Step 1 — loads: compute wind (to IS 875 Part 3 for the site basic wind speed) on the conductor spans + the pole projected area, plus any unbalanced tension; resolve to an equivalent tip load, say ≈ 2.0 kN.

Step 2 — select: choose an IS 2713 designation whose rated working tip load ≥ 2.0 kN for an 8 m pole (with the standard factor), e.g. an appropriate 410-series pole.

Step 3 — deflection: confirm the selected pole's tip deflection at working load is within the IS 2713 limit (no permanent set).

Step 4 — foundation: planting depth ≈ 8/6 ≈ 1.35 m, in compacted soil or a concrete muffing block sized for the overturning moment; closer-spaced/guyed at angles and dead-ends.

Step 5 — protection: specify hot-dip galvanizing to IS 4759; critical in the coastal environment.

1. Selecting on length only, ignoring tip load. Two 8 m poles can have very different working capacities — size on the *computed tip load*, not the height.

2. Under-estimating wind/unbalanced load. Missing conductor wind, the higher coastal wind zone, or dead-end/angle unbalanced tension overloads the pole and it bends or sets.

3. Inadequate planting/foundation. Under-depth or poorly compacted/concreted foundations cause leaning and progressive failure — the pole is fine, the foundation isn't.

4. No or poor galvanizing at the ground line. The soil/air interface is where tubular poles corrode through first — full HDG and, ideally, ground-line protection.

5. Not guying angle/terminal poles. Straight-run poles and angle/dead-end poles are different problems; the latter need guys or a heavier designation.

• IS 875 Part 3 — wind loads on structures
• IS 800 — general construction in steel
• IS 5613 (parts) — design, installation and maintenance of overhead power lines
• IS 2629 / IS 4759 — hot-dip galvanizing practice and coating mass
• IS 7321 — selection of current-carrying conductors · IS 8263 — pole testing
• IS 2062 — steel for the tubes / fittings

IS 2713 tubular poles remain the workhorse for LT/HT distribution and street lighting, competing with spun/prestressed RCC poles (IS 1678) and rail/joist poles; tubular is light, quick to erect and easy to galvanize, which is why utilities standardise on the IS 2713 designations. The 2000 revision is reaffirmed and still the procurement reference, with utility-specific (e.g. state DISCOM/REC) schedules layered on top.

The lifelong failure mode is ground-line corrosion and inadequate foundations, not tube strength. The practitioner discipline: design the tip load honestly (full wind to IS 875 Part 3 for the *actual* wind zone, plus unbalanced tension at angles/dead-ends), select the pole designation on that load with deflection checked, detail the foundation/planting for overturning, and specify full hot-dip galvanizing with ground-line protection. Get those four right and the IS 2713 pole lasts its full service life.