Tubular Steel Poles for Overhead Power Lines

Scope of IS 2713 (Part 1-3) - Key Specifications & Tables

IS 2713 Part II (1980) covers tubular steel swaged poles with detailed dimensions, structural properties, and loading data.

Key Points:

• Wind Load Basis: Equivalent wind load based on wind pressure of 1000 N/m² (approx 100 kgf/m²) on flat surfaces.
• Pole Sections: Poles divided into Top, Middle, Bottom sections with specific outside diameters and thicknesses.
• Material: Steel with ultimate tensile strength of 410 MPa.
• Design Parameters:
  • Overall Height (H) above ground (m)
  • Planting Depth (m)
  • Length of Sections (m)
  • Outside Diameter and Thickness (mm)
  • Moment of Inertia (I) and Section Modulus (Z) for each section
  • Equivalent Wind Load (P1, P2) acting at resultant line A-A
  • Breaking, Crippling, Working Loads (N or kgf)
  • Load for Permanent Set and Temporary Deflection

Important Formula:

• Total Wind Load: [ P = P_1 + P_2 ] where,
  • (P_1) = Equivalent wind load on pole
  • (P_2) = Equivalent wind load on conductors

Sample Table Extract (Pole Dimensions & Properties):

IS 2713 Part 1-3: Material Requirements Summary

1. Material Weight Assumption

• Steel density assumed as 7.85 g/cm³ (Note 1, Clause 7.00 & 219.1).

2. Tube Joint Lengths (Clause 5.4, Table 5)

• J1 or J refers to the length of the joint in tube connections.

3. Chemical Composition (Clause 6)

• Refer to Clause 219.1 for detailed chemical composition requirements.
• Material supply must comply with IS 1387-1967 (Clause 4.1).

Additional Notes:

• Use the steel density to calculate weight:
  [ \text{Weight (kg)} = \text{Volume (cm}^3) \times 7.85 \times 10^{-3} ]
• Ensure joint lengths match the tube diameter for structural integrity.

flowchart TD
    A[Tube Outside Diameter] --> B{Select Diameter}
    B -->|76.1 mm| C[Joint Length = 200 mm]
    B -->|88.9 mm| D[Joint Length = 230 mm]
    B -->|114.3 mm| E[Joint Length = 300 mm]
    B -->|139.7 mm| F[Joint Length = 350 mm]
    B -->|165.1 mm| G[Joint Length = 400 mm]
    B -->|193.7 mm| H[Joint Length = 450 mm]

This ensures compliance with IS 2713 material and joint specifications.

Manufacture Specifications (IS 2713 Part 1-3)

1. Joint Lengths (Clause 5.4):
The length of the joint (J or J1) depends on the outside diameter of the smaller tube in the joint:

2. Structural Properties (Clause 7.58):
Key parameters for tubular steel swaged poles include:

• Effective length (cm)
• Section modulus (cm³)
• Moment of inertia (cm⁴)
• Cross-sectional area (cm²)
• Equivalent wind load (N or kgf)

Refer to Table 4 (IS 2713 Part II) for detailed values per pole designation (SP-1 to SP-29).

3. Chemical Composition:
Steel weight assumed as 7.85 g/cm³.

Summary Diagram of Joint Lengths vs Diameter

graph LR
A[76.1 mm] -->|200 mm| B[Joint Length]
C[88.9 mm] -->|230 mm| B
D[114.3 mm] -->|300 mm| B
E[139.7 mm] -->|350 mm| B
F[165.1 mm] -->|400 mm| B
G[193.7 mm] -->|450 mm| B

For detailed design, use the structural properties table to select poles based on load and length requirements.

IS 2713 Part 1-3: Dimensions & Structural Properties of Tubular Steel Swaged Poles

Key Specifications (Clause 5.1 & 7.58)

• Dimensions for poles are specified in Table 1 (stepped poles) and Table 2 (swaged poles).
• Structural properties (section modulus, moment of inertia, cross-sectional area) are tabulated based on these dimensions.
• Equivalent wind load is based on a wind pressure of 1000 Pa (approx 100 kg/m²) on flat surfaces.

Important Structural Properties (Excerpt from Table 4)

Sample Formula for Wind Load on Pole Surface

[ W = p \times A ]

• (W) = Wind load (N)
• (p) = Wind pressure (1000 Pa)
• (A) = Projected area of pole surface (m²)

Dimensions & Load Table Sample (from Table 2)

Mechanical Testing - IS 2713 (Part I-III) Key Points

1. Permanent Set Test (Clause 10.1.4)

• Conduct immediately after deflection test.
• Load as per Tables 1-4 (Part II) and Tables 1-2 (Part III).
• Permanent set ≤ 13 mm at load application point after unloading.

2. Structural Properties for Design (Clause 5.2 & Table 4, Part II)

• Tables provide:
  • Effective length (cm)
  • Section modulus (cm³)
  • Moment of inertia (cm⁴)
  • Cross-sectional area (cm²)
  • Equivalent wind load (N or kgf)
• Useful for design and mechanical testing of tubular steel poles (high tensile & mild steel).

3. Equivalent Wind Load

• Based on wind pressure of 1000 MPa (~100 kgf/mm²) on flat surface.

Sample Table Extract (Structural Properties)

Summary

• Use Tables 3 & 4 (Part II) for mechanical properties during testing.
• Perform Permanent Set Test per Clause 10.1.4 with max allowable permanent deformation of 13 mm.
• Wind load values are critical for load application during tests.

flowchart TD
    A[Load Application] --> B[Deflection Test]
    B --> C[Permanent Set Test]
    C -->|Measure Permanent Set| D{Permanent Set ≤ 13 mm?}
    D -->|Yes| E[Test Passed]
    D -->|No| F[Test Failed]

For detailed

IS 2713 Part 1-3: Chemical Composition Key Points

Chemical Composition Requirements (Clause 6)

• Phosphorus (P) and Sulphur (S) content must be tested for each coil of sheet/strip.
• Testing standards:
  • IS 228 (Part III) - 1972
  • IS 228 (Part IX) - 1975
• Maximum allowable content:
  • Phosphorus ≤ 0.060%
  • Sulphur ≤ 0.060%

Testing Procedure

• Chemical analysis is mandatory before tube manufacturing.
• Ensures material quality and prevents brittleness or weld defects.

Related Table (Clause 5.4) - Tube Joint Lengths by Diameter

Additional Notes

• Steel density assumed: 7.85 g/cm³ (for weight calculations).
• Chemical limits ensure weldability and structural integrity.

If you need formulas for chemical analysis or defect tolerance, please specify!

IS 2713 Part 1-3: Load Calculations - Key Formulas & Tables

1. Equivalent Wind Load Calculation

• Wind pressure on flat surface: p = 1000 N/m² (approx. 100 kgf/m²)

• Equivalent wind load on pole and conductors at resultant line A-A:

  [ P = P_1 + P_2 ]

  Where:

  • (P_1) = Equivalent wind load on pole
  • (P_2) = Equivalent wind load on conductors
  • Both loads act at line A-A (see Fig. in Part II Tables 3 & 4)

2. Pole Dimensions & Structural Properties (Excerpt from Table 4)

(Refer to the full table for all pole designations and detailed sectional properties.)

3. Load Parameters (from Clause 1.1)

• (H) = Overall height above ground (m)
• (D_1, D_2, D_3) = Outside diameters of top, middle, bottom sections (cm)
• (p) = Wind pressure (N/m²)
• (n) = Number of conductors
• (d) = Diameter of conductors (cm)
• (s) = Sum of half spans on each side (

Pole Selection & Safety Factors (IS 2713 Part 1-3)

Key Points from Clause 2.5:

• Factor of Safety (FoS) must be applied on:
  • Crippling Load (FoS = 2.0)
  • Breaking Load (FoS = 2.5)
• Working load = (Crippling or Breaking load) ÷ FoS
• Tables provide working loads for these FoS values (Table 1 or 2 in Part II/III).
• For other FoS values, users must calculate working loads accordingly.

Formula for Working Load:

[ \text{Working Load} = \frac{\text{Crippling Load or Breaking Load}}{\text{Factor of Safety}} ]

Pole Selection:

• Use Tables 1 & 2 (Part II & III) for high strength poles.
• Use Tables 3 & 4 (Part II) for mild steel poles.

Example Table Extract (Conceptual):

Summary:

• Always apply FoS before selecting poles.
• Use standard tables for quick reference.
• Calculate working load for non-standard FoS.
• Follow electricity rules for FoS choice.

flowchart TD
    A[Determine Pole Load] --> B{Select Load Type}
    B -->|Crippling Load| C[Apply FoS = 2.0]
    B -->|Breaking Load| D[Apply FoS = 2.5]
    C --> E[Calculate Working Load]
    D --> E
    E --> F[Select Pole from Tables]

This ensures safe, code-compliant pole selection.

Welding and Joint Details per IS 2713 (Part I-III):

1. Joint Length (Clause 5.4)

• Joint length (J or J1 in Fig.1) depends on the smaller tube's outside diameter.
• Swaging requires chamfering upper edge at ~45°, unless a circumferential weld is applied (Clause 5.3.1).

2. Weld Quality (Clause 12.2)

• Welded joints must be free from scale, surface defects, cracks.
• Good quality welds ensure structural integrity.

3. Structural Properties (Clause 7.58 & Table 4)

• Refer to Table 4 for section modulus, moment of inertia, and sectional area for tubular steel poles.
• Use these for verifying weld and joint adequacy under load.

Summary Diagram: Joint Detail Concept

flowchart LR
    A[Smaller Tube] -->|Chamfer 45°| B[Joint End]
    B --> C[Swaged Joint]
    C --> D[Welded Circumferential Joint]
    D --> E[Final Pole Assembly]

Use these specifications to ensure proper joint length, welding quality, and structural performance in tubular steel poles as per IS 2713.

IS 2713 Part 1-3: Surface Finish and Straightness Key Points

Surface Finish (Clause 12.5)

• Thickness tolerance based on thickness-to-outer diameter ratio:
  • If ( \frac{t}{D} > 3% ), thickness tolerance = -12.5% of specified thickness.
  • If ( \frac{t}{D} \leq 3% ), thickness tolerance = -15% of specified thickness.

Straightness

• No explicit clause in provided context; generally, straightness tolerances for tubular poles follow industry norms:
  • Maximum allowable deviation typically limited to 0.5% of pole length or as per manufacturer's specification.
  • Visual inspection and measurement over full length recommended.

Joint Length (Clause 5.4)

Additional Notes:

• Surface finish quality affects corrosion resistance and pole durability.
• Straightness ensures structural stability and proper fitment of poles.

flowchart LR
A[Surface Finish] --> B{Thickness to Diameter Ratio}
B -->|>3%| C[-12.5% thickness tolerance]
B -->|≤3%| D[-15% thickness tolerance]
E[Straightness] --> F[Max deviation ~0.5% length]
G[Joint Length] --> H[Depends on smaller tube diameter]

For detailed structural properties and dimensions, refer to TABLE 4 & 2 in IS 2713 Part II (1980).

IS 2713 Part 1-3: Installation Requirements - Key Formulas & Tables

1. Equivalent Wind Load

• Based on wind pressure = 1000 MPa ≈ 100 kg/mm² on flat surfaces.
• Used for design wind load ( W_1 ) on poles.

2. Structural Properties of Tubular Steel Swaged Poles (IS 2713 Part II - 1980)

• Steel grade: Ultimate tensile strength = 410 MPa (12 kgf/mm²)
• Poles classified by designation (e.g., SP-1 to SP-80).
• Key parameters per pole type include:

3. Typical Formula for Pole Design (Wind Load)

[ W = p \times A_{eff} ]

• ( p ) = wind pressure (N/m²)
• ( A_{eff} ) = effective projected area of pole (m²)

4. Installation Notes:

• Embedment depth and planting depth as per table for stability.
• Use specified sectional dimensions for strength.
• Check loads against breaking, crippling, and working loads from tables.
• Ensure permanent set load and temporary deflection limits are not exceeded.

Example Extract from Table (SP-58 Pole):

IS 2713 Part 1-3: Sampling and Inspection Key Points

Sampling for Mechanical Tests (Clauses 5.1.1 & 5.1.2)

• Sampling standard: IS 4711-1974 — Methods of sampling steel pipes, tubes and fittings.
• Sampling size depends on the number of tubes in the lot.
• Ensures representative mechanical test specimens.

Chemical Composition Limits (Clause 6.1)

• Sulphur (S) ≤ 0.060%
• Phosphorus (P) ≤ 0.060%
• Analysis per IS 228 (Part III & IX).

Structural Properties (Clause 5.2)

• Refer to Tables 3 & 4 in IS 2713 for key mechanical properties useful in pole design (e.g., tensile strength, yield strength, modulus of elasticity).

Summary Table: Sampling & Inspection

Diagram: Sampling Process Flow

flowchart TD
    A[Start: Lot of Tubes] --> B{Lot Size?}
    B -->|Small| C[Sample per IS 4711]
    B -->|Large| D[Sample per IS 4711]
    C --> E[Mechanical Testing]
    D --> E
    E --> F{Chemical Analysis}
    F -->|Pass| G[Accept Lot]
    F -->|Fail| H[Reject Lot]

For detailed sampling numbers and acceptance criteria, consult IS 4711-1974 directly.

IS 2713 Part 1-3: Load Deflection Limits Summary

Key Specifications:

• Temporary Deflection Limit: Maximum deflection at load application point = 157.5 mm (Clause 2.3)
• Permanent Set Limit: After load removal, permanent set ≤ 13 mm (Clause 10.1.4)

Load Values (for Temporary Deflection 157.5 mm):

Deflection Test Procedure (Clause 10.1.3):

• Pole supported rigidly at planting depth.
• Load applied as cantilever at:
  • 30 cm from top for poles ≤ 9 m length
  • 60 cm from top for poles > 9 m length
• Load applied perpendicular to pole axis.
• Deflection at load point ≤ 157.5 mm.

Important Formula for Cantilever Deflection:

[ \delta = \frac{P L^3}{3 E I} ]

Where:

• ( \delta ) = deflection (mm)
• ( P ) = applied load (N)
• ( L ) = length from support to load point (mm)
• ( E ) = modulus of elasticity (N/mm²)
• ( I ) = moment of inertia of cross-section (mm⁴)

Testing Sequence:

flowchart LR
    A[Support Pole at Planting Depth] --> B[Apply Load at 30/60 cm from Top]
    B --> C[Measure Temporary Deflection ≤ 157.5 mm]
    C --> D[Remove Load]
    D --> E[Measure Permanent Set ≤ 13 mm]

This ensures pole strength and serviceability under load per IS 2713 standards.

IS 2713 Part 1-3: Marking and Identification Key Points

Marking Requirements (Clause 16.1 & 16.2)

• Poles must be marked with:
  • Designation
  • Manufacturer's identification
  • Year of manufacture
• Optional marking:
  • ISI Certification Mark (subject to ISI licensing rules)

Marking Details Table (Clause 16.2)

Additional Specifications

• Holes for taper plug: 23 mm diameter, 3 equally spaced
• Set screws: 10 mm, conforming to IS:4218 (Part I)
• Base Plate Dimensions: (all in mm)

Notes:

• Holes in poles are not tapped.
• Holes in finials are tapped for screws.

Summary Diagram of Marking & Identification

graph TD
    A[Pole] --> B[Designation Mark]
    A --> C[Manufacturer ID]
    A --> D[Year of Manufacture]
    A --> E{ISI Mark?}
    E -- Yes --> F[ISI Certification Mark]
    E -- No --> G[No ISI Mark]

Use this marking to ensure traceability, quality assurance, and compliance with IS standards.

Detailed content not available.