OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 9 Fall Protection

Section 160 Work positioning

A work positioning system is a system of components attached to a vertical life safety rope and includes a full body harness, descent controllers and positioning lanyards used to support or suspend a worker at a work position. A work positioning system allows a worker to work at height supported in tension, part or all of the worker’s mass being supported by the work positioning system and the remainder by the surface on which the worker is standing. The worker relies on both the tension provided by the anchor and his or her feet to maintain the work position. The worker may use an adjustable work positioning lanyard to further secure his or her work position. Work positioning can be used in occupational settings such as tree climbing, residential wood frame construction, residential roofing, high rise window cleaning, Christmas light installation, snow clearing on sloped roofs, etc.

If a work positioning system is used as a means of holding a worker in position at the work location, the worker should select and use a fall protection system based on the work surface slope characteristics described in Table 9.3. If the hazard assessment required by Part 2 indicates that the work surface presents a slipping or tripping hazard because of its state or condition, the employer must ensure that an appropriate fall protection system is used that takes into account the state or condition of the surface.

When a worker uses a work positioning system, tension is maintained at all times in the life safety rope(s) to which the worker is attached and slack in positioning lanyards is kept to a minimum at all times. Doing so helps ensure that the worker’s vertical free fall distance, in the event of al fall, is restricted by the positioning system to 600 millimetres or less.

Table 9.3 Selection of fall protection system to be used with work positioning, based on work surface and slope

Class

Work surfaces and slope characteristics

 Required back-up fall protection plan

I

Flat – with a slope of no more than 4 degrees None, unless the worker’s centre of gravity extends beyond the edge, in which case a back-up fall arrest system is required.

II

Slight elevation gain or loss – slope angle varies from 4 to 8 degrees None, unless the worker’s centre of gravity extends beyond the edge, in which case a back-up fall arrest system is required.

III

Sloping sharply enough that a person needs to touch a hand for balance None, unless the worker’s centre of gravity extends beyond the edge, in which case a back-up fall arrest system is required.

IV

Hands and feet or the work positioning system is required to maintain the work position on a sloping surface Travel restraint system unless the worker’s centre of gravity extends beyond the edge, in which case a back-up fall arrest system is required.

V

Vertical surface. Worker is suspended Fall arrest system.

Figures 9.22, 9.23 and 9.24 show workers using work positioning systems in various applications.

Figure 9.22 Worker on communication tower using tower climbing harness and work positioning system

Figure 9.23 Worker repairing roof structure while using work positioning system

Figure 9.24 Worker using work positioning system for travel restraint on a roof