Whether you’re towing for the first time or you’re an experienced tower, you may have some questions or doubts on the requirements of having compliant safety trailer chains. The team at Sunrise are here to help make sure you have the right answers to meet legal requirements.
The Legal Requirements of Safety Chains
Safety chains are mandatory throughout Australia. They serve to maintain the connection between a trailer and its towing vehicle should there be any coupling failure. The first step in finding the right chain is to understand the term Aggregate Trailer Mass (ATM). The ATM is the total weight of a trailer and its maximum (or full) load when NOT coupled to a vehicle. This figure is commonly stamped onto the trailer VIN plate. Safety chains must be marked in accordance to the relevant Australian Standard and your trailer ATM.
Australian Standard for Safety Chains
Safety chains are an important component of trailer safety in Australia and must comply with Australian Standards AS 4177.4-1994 or AS 4177.4-2004. These standards outline the requirements for safety chains on trailers and other vehicles that are used for towing.
Where Should I Attach Safety Chains?
According to these standards, safety chains must be attached to the tow vehicle and the trailer in a way that prevents the trailer from becoming detached in the event of a failure of the tow hitch or other connection. Safety chains must be of a suitable size, strength, and design to prevent the trailer from separating from the tow vehicle.
The safety chains must be attached to the tow vehicle and the trailer in such a way that they are taut when the trailer is connected to the tow vehicle, but not so tight that they impede the movement of the trailer. They must also be easily accessible for inspection and maintenance.
It’s also important to note that safety chains must be visible and not obscured by any other equipment or parts of the trailer or tow vehicle.
Where Can i Purchase Safety Chains
Sunrise has an extensive range of safety chains. You can view all our safety chains here.
What Rating is Required for Safety Chains on Trailers?
The standard also specifies the minimum breaking strength of the safety chains, which is typically around 2.5 times the Gross Trailer Mass (GTM) of the trailer. It also specifies the minimum number of safety chains that must be used, which is typically two.
Your trailer ATM will help to determine which safety chain you will need. See the guide below to help you find your suitable safety chain:
ATM less than or equal to 2.5T
If your trailer ATM does not exceed 2.5 tonnes, you must have at least one safety chain complying and stamped with
Australian Standard AS 4177.4-1994 or Australian Standard AS 4177.4-2004 “Caravan and light trailer towing components, Part 4: Safety chains up to 3500 kg capacity”.
2.5T < ATM ≤ 3.5T
If your trailer ATM is over 2.5 tonnes but does NOT exceed 3.5 tonnes, you must have two safety chains complying and stamped with Australian Standard AS 4177.4-1994 or Australian Standard AS 4177.4-2004 “Caravan and light trailer towing components, Part 4: Safety chains up to 3500 kg capacity”.
ATM > 3.5T
If your trailer ATM is over 3.5 tonnes, the safety chain must be permanently attached to the trailer; shackles are not permitted. The safety chain must not be welded to the draw bar. Alternatively, a plate welded to the draw bar, or an appropriate device like the Hammerlock Hook may be used. You must have two safety chains made of steel. They must have a minimum 800 MPa breaking stress that conforms to the mechanical properties of Grade T chain. This is specified in Australian Standards AS 2321-1979 “Short Link Chain for Lifting Purposes (Non Calibrated)“.
Alternatively, safety cables with equal capacity to the relevant safety chains may be used on towing vehicles with ATM up to 3.5T.
Note: Any trailer without breakaway brakes must be fitted with safety chains that are marked in accordance with relevant Australian standards depending on your trailer ATM.
Contact your local Sunrise store for more information on your trailer safety chains and trailer ATM. We are always happy to help, visit us in store where a team member can assist with any enquiries you may have.