We are frequently asked for clarification from our customers on the requirements for safety chains for caravans. There are a few misconceptions about safety chains and the correct requirements. Your safety chains will prevent your caravan from completely detaching from your vehicle in the event of a coupling failure so it is important that they are attached correctly with the appropriate load ranking.
This information guide relates to caravans up to 3.5T ATM.
Reference for Safety Chain Sizes
|Van ATM||# Chains / Shackles Required||Chain Size||Marking on Chain||Min chain breaking load||Recommended Rated D Shackle per chain|
|0 – 1000 kg||1||6.3 mm||4177-10||1000kg||8mm|
|Up to 1600 kg||1||8 mm||4177-16||1600 kg||8mm|
|Up to 2500 kg||1||10 mm||4177-25||2500 kg||10mm|
|Up to 3500 kg||2||13 mm||4177-35||3500 kg||13mm|
Safety Chains must:
- meet Australian Standard AS 4177.4
- be permanently and legibly marked with:
- Importer or manufacturers unique identification
- The digits 4177 (the standard number) and
- The first two digits of the chain rating/designation (e.g. where the chain is rate to 21500kg – the digits ‘25’ would be present’
- Repeated at intervals not exceeding 4 links.
Arrangement of chains
- Must be permanently attached to the trailer. If welded – 50% of the link welded. Alternatively, a plate and Hammerlock type fitting may be used. (Over 3.5T must not be welded)
- Support the drawbar to prevent it dropping to the ground in event of coupling failure. This does not require crossing the chains, but that may help in the event that the caravan becomes detatched from the vehicle.
The biggest issue with safety chains is the wear that occurs on the chains from drag on the ground when going over bumps, driveways etc. It doesn’t take much to wear through the chains. At the RV Service Centre we inspect chain condition and connection as part of our standard caravan service. If you have any concerns with your safety chains get in touch with our friendly team. For information on the requirements for d shackles for caravan towing, read our article here.