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MINIMISING RISKS WHEN WORKING AT HEIGHT

BASIC PRINCIPLES OF ANCHORAGE SYSTEM DESIGN Working at Height Association (WAHA)

Working at height — whether on maintenance and cleaning operations on high-rise buildings or on new construction work — has been, and always will be, a risk activity.

H

ow many times have you looked up in the city and seen workers hanging from ropes down the side of a high-rise building? How many times have you looked down from a highrise building to see people working along the edge of roofs on warehouse-style buildings or lower-rise apartments? How many times have you passed a construction or worksite and seen workers perched up in the structure carrying out construction work? A closer look at those workers would reveal that they are wearing specialist fall arrest equipment and are ‘anchored’ to the structure in a way that allows them to both move about the work area but would arrest any accidental fall in a safe distance. However, recent accidents from working-at-height activities reported from both Queensland and New South Wales highlight the need to re-enforce the basic principles that must be observed to ensure that the risks from falls are to be minimised through the correct design, installation, testing and recertification of workingat-height anchorage systems. A summary of these principles is detailed below.

1. Safety system design The overall safety system must be designed to suit the specific tasks that will be required to be undertaken. This will include consideration of all aspects of the system — from safe access, personal protective equipment to be worn, the anchorage system to be used, the work methods to be used to move around the task area, safe egress on completion of the work and a rescue plan in the event that something unforeseen happens. The system should be designed by a person deemed to be competent in such work. 10 This issue is sponsored by — MSA — http://au.msasafety.com/?locale=en

This will include engineering skills to ensure that the parts of the building structure used for the fitting of anchorages are capable of bearing the loads resulting from arresting a fall.

2. Clearances under work areas The system design must take into consideration what is below the work movement area, including access and egress. This is to ensure that there are adequate clearances so that, if a worker falls, they will not hit any object or protrusion before the fall is arrested. Clearances need to take into consideration the lanyard length, shock absorber extension, possible harness stretch and anchorage extension (particularly on lifeline systems). AS/NZS1891.4 – Section 7 gives good guidance on this subject. Consideration should also be given to protecting the area below from possible falling material and ensuring tools are tied off to prevent them falling.

3. System access and egress Without safe access, a worker can be exposed to a fall before he or she reaches the designated work area. With this in mind, safe access to and from the anchorage system must be considered as an integral part of the overall work method and the overall safety system. Fall hazards getting to the work area can be minimised by the use of stairways and ladders for getting to height, and the use of walkways and guardrails for horizontal access. Vertical anchorage systems may be required on ladders — with particular care taken in the transfer of personnel anchorage from vertical to horizontal activity.

4. System attachment equipment and personal protective equipment The correct equipment to be used for the task needs full consideration. The correct harnesses, attachment hardware, lanyards

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Safety Solutions Oct/Nov 2015  

Launched in April 2003, this bi-monthly magazine provides vital information on safety products and services in the industrial, construction,...

Safety Solutions Oct/Nov 2015  

Launched in April 2003, this bi-monthly magazine provides vital information on safety products and services in the industrial, construction,...