Rated d shackles for caravans are something our customers frequently ask us about. There is no legal specification for d shackles in relation to trailers, however, it is strongly recommended that shackles comply with AS 2741-2002 Shackles. The standard covers the use of shackles for lifting purposes, and not specifically for use in an application such as attaching a trailer to a tow bar.
So, for example, an 11mm d Shackle has a “Working Load Limit (WLL)” of 1500kg. This chain can lift a maximum load of 1500kg. In a towing application, as the breaking load is generally 6x the WLL, it could effectively be used for a towing load of over 6,000 kg.
Our recommendations for d shackles for caravans is based on the chain diameter, and ensuring breaking strain is more than the chain rating.
The shackle itself should:
- Meet the requirements of AS 2741-2002 – ie be a “Rated” D shackle
- Shackle grade is “S” or “6”
- Either “Bow” or “Dee” shackle design is suitable, although it is noted that the “Bow” design provides a greater angular displacement.
Does it fit?
One of the largest hassles with the d shackles is whether the connection point on the tow vehicle actually has enough space to get either the pin, or “D” part of the shackle attached to it. Often people are forced to use a smaller shackle as that is all that will fit on the vehicle. It is best to modify the vehicle so that the correct size shackle fits, however, providing the breaking load of the shackle is greater than the chain rating, using a smaller shackle may be suitable.
The connection point to the vehicle is also important – it is better to have the d shackle connected to the fixed part of the actual tow bar, not the removable part (tongue/weight distribution head).
Extending Safety Chains
Again, there is no specific regulation that says you cannot extend a safety chain using d shackles in a towing application. However, from our experience, it is best to use a hammer-lock chain extension system.
For information on the requirements for safety chains for caravans, read our article here. At the RV Service Centre we keep a full range of towing safety gear including all the sizes of d shackles for caravans you may need in our showroom. Our professional team can ensure that you are safely on the road with the right gear.