D Shackle Myth
There has been an industry myth floating around (like a bad smell 🙂 ), for quite a while now in regards to the D Shackle when towing. The myth is that the D shackles by law must be rated to an industry standard. This is not true!
This standard does not specifically cover the use of rated shackles in an application such as attaching a trailer to a tow bar. This standard covers the use of shackles for lifting purposes, NOT towing a trailer. From what we understand there is currently no regulation requiring shackles used on trailer safety chains to comply with the Australian Standards. However, some state authorities provide guidelines or advise for selecting suitable shackles. These are quite handy to refer to when travelling from job to job with your mini loader in tow.
Below is a table taken from the QLD Department of Transport and Main Roads which shows you a guidance table on safe towing and which shackle to select for your vehicle.
Guide to selecting shackles
|Trailer ATM (kg)||Chain size classification
|Suitable rated D shackle size
Grade ‘S’ or ‘6 dee’ or ‘6 bow’
|Minimum proof load strength (kN)
chain / shackle
|Up to 1,000||1,000||4177-10||6mm S WLL 0.5T||4.9 / 9.9|
|Up to 1,600||1,600||4177-16||6mm S WLL 0.5T||7.9 / 9.9|
|Up to 2,500||2,500||4177-25||8mm S WLL 0.75T||12.3 / 14.8|
|Up to 3,500||3,500||4177-35||10mm S WLL 1.0T||/ 19.7|
This is a handy piece of information for purchasing any plant or equipment trailer.