Suspended scaffold failure
First published: June 2008
Purpose
Background
Obligations to ensure safe use
Legislative requirements
Purpose
To alert all persons conducting a business or undertaking, whether as employer, self-employed person or otherwise (and in their capacity as principal contractors) designers, manufacturers, suppliers, installers, owners of suspended scaffolding and workers of the risk of falling from suspended scaffolds (i.e. swingstage cradles).
Information on the safe use of scaffolding can be obtained from the Scaffolding Code of Practice 2004.
Background
A number of serious incidents have occurred in Queensland and other parts of Australia when workers have fallen from swingstage cradles. On 21 June 2008, two workers were fatally injured at a Gold Coast construction site when the support system to the suspended scaffold appeared to have failed.
Obligations to ensure safe use
Principal contractors, employers and self employed persons have an obligation to assess the risks of using suspended scaffolds. Risk assessment is to include:
Engineering verification
Prior to being set up, verification of the structural adequacy of the suspension system and the cradle is to be obtained by the installer of the scaffold. The manufacturers of the cradle and hoist are to provide the structural verification and information on the maximum safe working load (SWL). The suspension and supporting structures are to be designed by a suitably qualified engineer.
Loading
The safe working load (SWL) is to be clearly marked on the cradle of the suspended scaffold. The SWL of a cradle will depend on factors such as its length, type of construction and material type. Longer cradles will generally have a reduced SWL. Materials loaded into the cradle should be evenly distributed and not concentrated in one area.
To prevent overloading, swingstage operators must verify the mass of the load to be included in the cradle.
Load-limiting devices
AS 1576 Part 4 - Suspended scaffolding, specifies electric scaffold hoists shall have a device to limit the lifting capacity of the hoist to a maximum of 1.25 times the rating of the hoist. Whatever the hoist stall capacity is, the suspension system and the cradle is to be designed to withstand the stalling load applied by all scaffold hoists in use. This feature prevents failure in the event of the cradle snagging on an obstruction.
Installation
Persons holding an Advanced Rigger or Advanced Scaffolder certificate under the National Certification system must be engaged to install suspended scaffolds.Inspection
Swingstage components are to be inspected for damage, wear and cracks before use and at pre-determined intervals. Some cracks may not normally be visible to the eye. Non-destructive testing is to be performed to check for cracks in high stress areas.
Fall arrest systems
Persons located in swingstage cradles are to wear fall arrest harnesses attached to a properly designed anchorage system. The current Scaffolding Code of Practice indicates that anchorage systems independent of the cradle and suspension system are preferred because they will support the worker if the cradle or suspension system fails. As a result of the recent incident of 21 June 2008, all installations, where practicable, should utilise an independently anchored individual fall arrest system. However, the use of an independent anchorage for fall arrest will introduce other risks. Therefore, a thorough assessment needs to be undertaken to ensure appropriate control measures are in place to address any secondary risks which might arise.
Where it is not practicable to implement independently anchored fall arrest systems, the obligation holder will need to introduce additional controls (over and above existing standards) to ensure the structural integrity and adequacy of the the cradle and suspension system.
Fall arrest systems must comply with part 17 of the Workplace Health and Safety Regulation 1997 and are to be designed by a competent person. Guidance on the design of fall arrest systems is also provided in Australian Standard AS 1891, ‘Industrial fall arrest systems and devices’.
Legislative Requirements
The Workplace Health and Safety Act 1995 (PDF, 766 KB) imposes health and safety obligations on all persons conducting a business or undertaking, whether as employer, self-employed person or otherwise (and in their capacity as principal contractors) designers, manufacturers, suppliers, installers and owners of plant, and workers.
The information contained in this Alert is designed to help persons meet their obligations regarding the management of risks associated with swingstages. More information on the safe use of scaffolding can be obtained from the Scaffolding Code of Practice 2004.
Last updated 22 July 2008