Training for Trees runs a number of courses that cover the sectional removal of trees, roping down techniques, and rigging systems.
It is a legal requirement that any personal protective clothing, machinery tools and workplace equipment conforms to relevant Australian Standards, is fit for purpose, is in good working order and is well maintained. It is also a requirement to follow any relevant industry codes of practice.
In Australia, the general amenity arboricultural industry currently has no specific code of practice in place. This makes it difficult for tree companies to find guidance to ensure full compliance with workplace health and safety obligations during the general scope of work.
One of the best ways to ensure compliance is to undertake nationally recognised training and assessment. This will help achieve the relevant qualifications/units of competency and maintain their currency with refresher/update training carried out at regular intervals.
A lot of equipment needed for arboricultural operations is specialised, therefore we need to use the services of specific arboricultural industry suppliers who stock equipment approved for use in Australia that is suitable and fit for industry needs.
It is highly recommended that advice from dealers, along with the equipment manufacturer’s recommendations and instructions, should be incorporated into your standard operating procedures, work method statements, and JSEA forms along with competent operators.
Recent training sessions in rigging and lowering show that some areas are often underestimated or misinterpreted by operators such as the weights and loads endured by the rigging equipment. There is also confusion caused by some terminology and manufacturers recommendations regarding the capacity of their products.
Here is an attempt to clarify the above, starting with the selection of appropriate and compatible equipment:
- Ropes come in a multitude of types, diameters, colours and strengths, with ratings generally classified as having a tensile strength in kilograms or sometimes given as a minimum breaking strain (MBS) or an average breaking strain (ABS)
- Friction devices, block pulleys and shackles are usually marked with a safe working load (SWL) or work load limit (WLL) sometimes depicted as tonnes or kilograms but commonly as kilonewtons (kN)
- Rated slings are often colour coded and must be marked by the manufacturer with their SWL in tonnes or kilograms on a clearly visible label attached to the product
- To increase confusion, some products are rated in the old pre-metric system of pounds (lbs)
It is important to select rigging kit components carefully and remember items such as the commonly used porta wrap. This is rated by one of the major manufacturers as having a SWL of 2000lbs which converts to just over 900kg, or less than one tonne.
Some components are marked with their SWL or WLL by the manufacturer, while other components only have their tensile or breaking strength listed on the invoice with no other markings on the product. You need to work out and apply a factor of safety of at least five, and that’s where the confusion sets in.
There is a difference between the tensile strength/breaking strain of a rope and its safe working load. Tensile strength is determined by the manufacturer as the force required to break it, which is determined by extensive testing.
There are many factors that can impact or reduce the strength of any rope.
These include the types of load to be lowered that are both static and generally dynamic, the tying of various knots/bends in the rope, its age, abrasion, UV exposure and the rope’s previous use and care.
To factor in the above variables a number is used to reduce the actual load that is placed on the rope. The industry usually defines this number as the standard required, and is called the factor of safety. The relationship between the safe working load and the rope’s tensile strength is termed the safety factor (SF).
The method for setting the SWL is to divide the breaking or the tensile strength, which is provided by the manufacturer, by the required factor of safety.
For example, if a rope is rated by the manufacturer as having a 5000kg tensile strength, or MBS, and we want to maintain a 10:1 safety margin, the maximum working load would be 500kg.
Items such as carabiners are usually marked in kN with their breaking strain. For example, to allow for a safety factor of 10, a 50kN carabiner will have a SWL or WLL of 500kg.
Once the gear is sorted, do not forget the importance of looking after it all. The gear can be expensive and can have pretty dire consequences if any of the components fail. Undertake a regular check of all rigging equipment on a daily per use basis using visual inspection techniques and keep records of purchase dates as well as inspection and use of equipment.
Written records in the form of a simple checklist are a very effective way to keep track of equipment, its age, safe working load limits, as well as frequency of use and expected life span of the item.
It is concerning to come across items of equipment that are used everyday but are well past their sell by date, not fit for purpose, or badly worn and damaged: pulleys that are stretched, damaged ropes that are nicked, worn carabiners that are deformed from overloading, and slings that are not compatible with the system.
In Europe the arboricultural industry is regulated under a system that is similar to what crane operators are required to follow. In a nutshell, this system calls for mandatory marking of equipment for identification purposes with daily and weekly checks recorded. Also, a thorough inspection must be carried out every six months on climbing gear and annually on all rigging and lowering equipment by an independent qualified assessor.
Textile items such as harnesses and webbing slings are generally considered to have a life span of five years with normal use. However, some manufacturers are now marking such items with life spans of up to 10 years, depending on frequency of use and storage conditions.
Ropes are high wear items and require more frequent inspection and replacement.
When carrying out kit inspections check all items for wear and tear, paying particular attention to the following checklist:
Ropes and textile items:
- Cuts and abrasions
- Burns or melting
- Age
- Chemical contamination
Textile items can lose their strength over time and manufacturers normally attach labels that indicate their life span.
Metal items:
- Corrosion
- Cuts
- Abrasion
- Cracks/Chips
- Deformation
- Age
- Chemical damage
Other important points to remember about equipment include:
- Never try to straighten any piece of equipment that has been bent or distorted
- Check for sharp edges on friction devices, rigging plate blocks, and pulleys, which can indicate impact damage and lead to cracks or cause rope damage
- As a rule of thumb, normal abrasion on metal items should not exceed 10 per cent of the item’s surface area
- Follow manufacturer’s recommendations for proper care and maintenance
- Do not store wet equipment in an enclosed space. It must be allowed to dry naturally
- Ensure that correct safe working load limits are adhered to
- Any items subject to a heavy shock loading or impact must be carefully checked and if the SWL has been exceeded they should be discarded
- Keep written records of inspections and age of equipment
- Label all equipment using suitable tags in areas away from load bearing areas so that it can be easily identified
- Ensure all equipment is compliant with relevant standards and is fit for purpose
Training For Trees has the capacity to carry out equipment identification and inspection systems and also demonstrate and factor these methods into courses.
As a minimum, we recommend that all climbers undertake complex tree climbing and aerial rescue training, along with the aerial and ground based rigging units. Groundies should also be encouraged to undertake ground based rigging training.
- AHCARB307A Undertake Complex Tree Climbing
- AHCARB306A Undertake Aerial Rescue
- AHCARB310A Perform Aerial Rigging
- AHCARB207A Perform Ground Based Rigging
“Everyone engaged in carrying out work around trees must be trained and qualified in their designated task and strive to maintain and improve their industry currency by continuing to gain relevant experience and qualifications”.
Training is as important the servicing of vehicles and machinery. After all, workers are the machinery that you run to operate your business. It has been proven that independent training and assessment increases safety awareness productivity and efficiency. Don’t forget to schedule in regular refresher and update training sessions.
For full trade level qualifications and apprenticeships to meet the industry standard requirement to be classified as a working arborist you will need to undertake the AHCARB30810 Certificate III in Arboriculture. Funding incentives currently apply to eligible applicants and their employers in QLD.
“Safety Rules!”
Enrol now for Cert III Arboriculture. Contact us for your short course RPL or refresher training needs. For details go to www.trainingfortrees.com.au