OHS Code Explanation Guide

Published Date: July 01, 2009
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Part 9 Fall Protection

Section 145 Self retracting device

CSA Standard Z259.2.2-98 (R2004), Self-Retracting Devices for Personal Fall-Arrest Systems, defines a self-retracting device (SRD) as a fall arrest device that performs a tethering function while allowing vertical movement (below the device) to the maximum working length of the device (see Figure 9.10). SRDs are designed to arrest a fall while minimizing fall distance and impact force. An SRD has a housing that is normally attached to the anchor of a fall arrest system. The housing contains a drum-wound lifeline.

The retracted end of the lifeline unwinds from the drum under the tension created by the worker’s normal movement below the device. When tension is released, the drum automatically retracts the lifeline. Once the speed at which the lifeline pays out reaches approximately 1.5 metres per second (5 feet per second), a velocity-sensing device engages a brake or locking mechanism that arrests the worker’s motion.

Only self-retracting devices approved to CSA Standard Z259.2.2-98 (R2004), Self-Retracting Devices for Personal Fall-Arrest Systems, are acceptable. This standard requires that Type 2 and Type 3 SRDs be inspected two years after being placed into service, and annually thereafter. Because of their critical importance to the safety of workers using them, and the mechanical workings inside the housing, these units need to be inspected regularly according to the manufacturer’s specifications. Because it is the only standard known to require such follow-up maintenance, it is the only standard listed in this section. For compliance purposes, the self-retracting device must bear the mark or label of a nationally accredited testing organization such as CSA, UL, SEI, etc. as evidence that it meets the requirements of the Standard.

Figure 9.10 An example of a self-retracting device used in the vertical position

CSA classifies SRDs into three types as follows:

Type 1 Self-Retracting Device (SRD)
This is a compact and lightweight SRD having a working length of 1.5 to 3.0 metres. Early versions of these devices resembled an automotive seatbelt mechanism and have a web-type lifeline. The internal locking mechanism of a Type 1 SRL is not capable of absorbing significant amounts of energy since it does not operate as a dynamic brake. The resulting deceleration distance is very short and the maximum arresting force will therefore be greater than if a Type 2 or Type 3 SRD were used.

Because of this greater arresting force, a Type 1 SRD should be used with a separate shock absorber if it is not already equipped with an integral shock absorber. Employers using these devices should carefully read the manufacturer’s specifications to confirm the conditions under which these devices can be used i.e. indoors versus outdoors, in dusty workplace settings. Many of these devices have markings that state that the peak impact force will be below 4 kN, but this is only tested by the manufacturer with the device overhead. Therefore, it is recommended that Type 1 SRDs only be used where the device is anchored above the worker. Like a standard lanyard, an SRD subjected to the force of a fall must be retired from service.

Type 2 Self-Retracting Device (SRD)
This is a heavier SRD, generally having a working length of more than 3 metres. It has an internal brake to minimize impact forces. The SRD must have a visual load indicator that allows the worker intending to use the SRD to determine if it has arrested a fall. Type 2 SRDs are repairable after a fall incident and are subject to a manufacturer’s service schedule. This type of SRD is also sometimes referred to as a self-retracting lifeline.

Type 3 Self-Retracting Device with Retrieval Capability (RSRD)
This type of SRD performs the same fall arrest function as a Type 2 device and has a visual load indicator. However, a Type 3 device incorporates a rescue winch that permits a single rescuer to raise or lower the victim to a safe level. Type 3 devices have a working length of more than 3 metres. This type of SRD is also sometimes referred to as a self-retracting lifeline.

Test before using

Workers should field test the locking feature of an SRD before using it by pulling down on the line quickly and forcefully. The visual load indicator on a Type 2 SRL or Type 3 RSRL should also be inspected. If the device does not lock or the visual load indicator has been activated, the SRD should be removed from service and returned to the manufacturer for re-certification. Only the manufacturer is capable of disassembling, refurbishing and re-certifying an SRD.

Proper use

To minimize free fall distance when using an SRD, the device must be anchored above the worker’s work location and there should be no slack in the lifeline (see Figure 9.11). The lifeline should not ride over any sharp edges. When under the tension of a fall, a lifeline in contact with the edge of an I-beam or hatchway opening can be damaged to the point of complete failure. The risk of damage and failure can be reduced by physically protecting the lifeline where it passes over an edge and using a shock absorber positioned between the worker’s D-ring and the free end of the SRD.

Figure 9.11 Example of a self-retracting device in use

Self-retracting devices and travel restraint systems

Self-retracting devices must not be used in a travel restraint system unless the length of the lifeline on the drum of the unit prevents the worker from reaching the edge from which he or she could fall. If a worker approaches the edge and there is some lifeline still spooled on the drum, the worker could go past the edge and fall.