OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 17 Overhead Power Lines

Section 226 Transported loads, equipment and buildings

This section clarifies that the distances listed in Schedule 4 do no apply to loads, equipment, or buildings less than 4.15 metres in height while they are being transported beneath energized overhead power lines. Examples of such situations include a tractor trailer passing beneath a power line or a building being transported on a flatbed trailer along a highway and passing beneath power lines.

The 4.15 metre height limitation comes from section 4 of the Commercial Vehicle Dimension and Weight Regulation (AR 315/2002) under the Traffic Safety Act. Vehicles and their loads must not exceed this height when operating on a highway unless Alberta Transportation has granted a special permit to do so.

For more information
Commercial Vehicle Dimension and Weight Regulation
Alberta Regulation 315/2002

The safe limit of approach distances do not apply because the clearance distance does not vary during transportation and “work” is not being performed. The distances always apply when loads and equipment are moved about on a work site when “work” is being done. Examples include a dump truck loading or unloading gravel, a mobile crane moving from one location to another at a work site, a rolling scaffold being repositioned.

Overhead power lines are installed at heights that allow equipment, buildings, or objects to be safely moved beneath them. The safe installation height varies depending on the location of the power line as shown in Table 17.2. These values are set by Rule 2-016(1) of the Electrical Communication and Utility Code (ECUC), 2nd Edition, 2002.

Table 17.2 Minimum height above ground of overhead power lines

Location of Overhead Power Line

Height Above Ground

Areas normally accessible to pedestrians only

3.6 m

Driveways to residences or residential garages

4.1 m

Areas where agricultural equipment is normally used

4.2 m

Lanes, alleys or entrances to commercial or industrial premises

4.8 m

Roads and highways

5.3 m

Right-of-way of underground pipelines

5.4 m

According to Rule 2-016(2) of the ECUC, equipment, a building, or an object exceeding the heights listed in Table 17.2 must not be moved under an overhead power line until the operator of the overhead power line is contacted and takes whatever steps are necessary to protect workers and the power line. The power line operator must be contacted before the move begins and the operator is required to provide assistance as soon as possible.

Some employers routinely (and perhaps on very short notice) move equipment, buildings, or objects exceeding the heights listed in Table 17.2. These employers may find it difficult to comply with Rule 2-016(2). It is suggested that the employer and the power line operator(s) work together to develop processes that anticipate such difficulties and ensure that the move is done safely.