Standard for Vertical and Horizontal Clearances of Overhead Electric Power and Telecommunication Lines as Related to Roads
1969 Edition

This section introduces the framework for vertical and horizontal clearance specifications for overhead electric power and telecommunication lines adjacent to roads. Highlights include:

• Applicability to poles and their supporting structures (Clause 5.5).
• Vertical clearance measurement from the lowest point of guard cradles or screens over the carriageway (Clause 3.1).
• Designation of minimum vertical clearances based on voltage classes: above 650 V, up to 650 V, and up to 110 V for telecom.
• Variations in minimum horizontal clearances for rural roads (with or without kerbs), urban roads, and street lighting poles.

Illustrative diagrams include:

These guidelines ensure safety and ease of access alongside highways.

References: Clauses 5.1, 5.5, 3.1; Figures 1, 2, 3

This part delineates the scope and practical application of the clearance norms for overhead electric and telecommunication lines near roads. Key points cover:

• Applicability to poles and supportive structures (Clauses 5.1 to 5.5).

• Vertical clearance measured from the lowest point of any protective guard cradles or screens above the carriageway (Clause 3.1).

• Minimum vertical clearances categorized by voltage:

  • Lines over 650 volts
  • Lines up to 650 volts
  • Lines up to 110 volts (telecommunication lines)

• Horizontal clearance requirements vary by road classification (rural or urban), kerb presence, and pole utility (street lighting, telecom, power).

Tables and figures illustrate these values:

These standards are designed to maintain safety and operational clearance near overhead lines.

References: Clauses 3.1, 5.1 to 5.5; Figures 1, 2, 3

This section clarifies the terminology and definitions relevant to clearance measurements according to the code:

• Vertical Clearance (Clause 3.1): The vertical space between the highest road surface (carriageway crown) and the lowest point of any overhead installation, including conductor wires, guard wires, stay wires, and protective devices, accounting for maximum sag.

• Horizontal Clearance (Clause 3.2): The perpendicular distance from the edge of the roadway or carriageway to the nearest point of a pole or its supporting structure carrying overhead lines.

• Application of Vertical Clearances (Clause 5.5): These apply explicitly to poles and supporting structures.

• Guard Cradles and Screens: Vertical clearance is measured from their lowest point above the carriageway (Clause 3.1).

• Minimum Clearance Values: Reflected in figures and plates (Fig-1, Fig-2, Fig-3), including horizontal minimums like 300 mm from raised kerb edges (preferably 600 mm).

These definitions provide a basis for maintaining safe clearances on both rural and urban roadways.

References: Clauses 3.1, 3.2, 5.5

This section details the vertical clearance requirements for overhead electric and telecommunication lines near roadways, aiming to ensure safety and clearance for vehicular traffic. Although specific numerical values are not included here, the standard sets minimum vertical distances determined by road classification, voltage level, and vehicle dimensions. These clearances guarantee safe vehicle passage and maintenance access. For exact figures, refer directly to IRC 32 tables and clauses categorizing clearances by voltage and road type, including highways and urban streets. Horizontal clearance criteria are also addressed to avoid contact risks.

References: Clause 4: Vertical Clearances

Horizontal clearance is defined as the perpendicular distance between the edge of the roadway or carriageway and the nearest point of a pole or its supporting structure carrying overhead electrical or telecommunication lines (Clause 3.2 of IRC 32). This clearance is crucial for ensuring safety margins and accessibility along roads with overhead lines. While exact numeric values are not specified here, the standard stresses maintaining sufficient horizontal separation to prevent hazards or interference. Detailed clearance values can be found in the full IRC 32 documentation under the relevant section.

References: Clause 3.2

IRC 32 outlines the following key points regarding guard cradles and protective screens:

• For electric power lines exceeding 110 volts crossing highways, installation of guard cradles or screens is compulsory and should preferably cover the entire right-of-way (Clause 4.2).
• For extra-high voltage lines on self-supporting towers with adequate safety margins, guard cradles may be exempted (Clause 4.2).
• Vertical clearance measurements must be taken from the lowest point of any overhead installation, including guard cradles or screens, over the carriageway, considering maximum sag (Clause 3.1).
• Minimum vertical clearance for power lines above 650 volts is set at 6.5 meters (Clause 6.5).
• Horizontal clearance distances depend on road type and kerb presence, with a minimum of 300 mm from kerb edge, preferably 600 mm (Figures 2 and 3).
• Urban areas may require greater clearances due to local conditions (Clause 4.3).

These provisions ensure safety aligned with vehicle dimensions and Indian Electricity Regulations.

References: Clauses 3.1, 4.2, 4.3, 6.5; Figures 2, 3

This segment highlights clearance requirements specific to urban environments as per IRC 32, focusing on the vertical and horizontal distances for overhead electric and telecommunication lines near roads. Vertical clearance is measured from the lowest point of guard cradles or screens above the carriageway (Clause 5.5). Horizontal clearances for poles in urban settings are specified in Figure 3 and apply to telecommunication, power, and street lighting poles. Poles near kerbs must maintain at least 300 mm distance from the raised kerb edge, with 600 mm recommended. Vertical clearance varies by voltage level; lines exceeding 650 volts require higher clearances than those up to 650 volts or telecommunication lines up to 110 volts, as depicted in Figure 1. These standards ensure operational safety and accessibility within urban roadways.

References: Clauses 5.1, 5.5; Figures 1, 3

IRC 32 prescribes particular clearance requirements for overhead electric power and telecommunication lines in mountainous regions. Vertical clearance is measured from the lowest point of guard cradles or protective screens above the carriageway (Clauses 4 and 5.5). Horizontal clearances for poles in hilly terrain differ from those on standard rural roads. Poles in mountainous areas must comply with minimum horizontal distances shown in Figure 2, distinguishing between roads with and without kerbs. For kerbed roads, a minimum of 300 mm from the raised kerb edge is mandatory, with 600 mm preferred. Vertical clearance depends on line voltage:

• Lines exceeding 650 volts require higher vertical clearance.
• Lines up to 650 volts have lower clearance demands.
• Telecommunication lines (up to 110 volts) require the least vertical clearance.

Figures 1, 2, and 3 illustrate these vertical and horizontal clearance requirements, including those for street lighting and poles in mountainous zones. These standards promote safety and accessibility in challenging terrains.

Summary Table:

Horizontal Clearance Details for Mountainous Roads:

• Without kerb: As per Fig-2(a)
• With kerb: Minimum 300 mm from kerb edge, preferably 600 mm (Fig-2(b))

Clearance rules apply to poles and their supporting structures (Clause 5.5).

References: Clauses 4, 5.5; Figures 1, 2, 3

According to IRC 32 Clause 5.3, horizontal clearance requirements for street lighting poles are:

• On roads with raised kerbs: A minimum distance of 300 mm from the kerb edge is required, with 600 mm preferred.
• On roads lacking raised kerbs: Although not explicitly stated here, clearance should adhere to general safety principles maintaining adequate distance from the carriageway edge.

Additionally, Clause 5.1 mandates that poles carrying overhead power and telecommunication lines (except within urban zones) must be positioned at least 10.0 meters from the nearest roadway edge and at least 5.0 meters from the closest line of avenue trees. These clearances also extend to pole-supporting structures (Clause 5.5).

In mountainous regions (Clause 5.2), poles should ideally be installed on the valley side, kept as distant from the road edge as feasible.

Vertical clearance is measured from the lowest point of any guard cradle or screen above the carriageway (Clause 3.1).

These provisions ensure the safe and accessible placement of street lighting poles along roads.

References: Clauses 3.1, 5.1, 5.2, 5.3, 5.5

IRC 32 mandates compliance with all applicable statutory provisions and clarifies that its clearance standards do not supersede legal requirements (Clause 2.2). Key points include vertical and horizontal clearance stipulations for overhead electric power and telecommunication lines near roads. Vertical clearance is measured from the lowest point of guard cradles or screens above the carriageway (Clause 5.5). Minimum vertical clearances vary by voltage classification: lines exceeding 650 volts, lines up to 650 volts, and lines up to 110 volts (telecommunication lines), as detailed in Figure 1. Horizontal clearances depend on road type and kerb presence, including minimum clearances such as 300 mm from raised kerb edges, with 600 mm preferred (Figures 2 and 3). These requirements apply equally to poles and their supporting structures (Clause 5.5).

References: Clauses 2.2, 5.1, 5.5; Figures 1, 2, 3

IRC 32 includes essential visual plates and diagrams illustrating vertical and horizontal clearance requirements for overhead electric power and telecommunication lines adjacent to roads. Highlights include:

• Vertical Clearances (Fig-1): Minimum vertical distances vary by voltage; lines above 650 volts require greater clearance than those up to 650 volts or telecom lines (Clause 3.1).

• Horizontal Clearances (Fig-2 & Fig-3): Minimum horizontal distances vary with road classification:

  • Rural roads without kerbs require poles to maintain minimum distance from roadway edges.
  • Roads with kerbs require poles to be at least 300 mm from the raised kerb edge, preferably 600 mm.
  • Specific provisions exist for street lighting poles and poles in mountainous regions.

• Application of Clearances: Standards cover poles and their support structures (Clause 5.5).

These diagrams support the enforcement of safety and accessibility around overhead lines near roadways.

References: Clauses 3.1, 5.5; Figures 1, 2, 3