Ideagen Plant Assessor News & Articles

AS 4772:2008 (quick hitches) - a decade of confusion

Written by Paul Dean | May 2018

Remember 2008? What a year! The iPhone 3 was released, Pink said So What while Katy Perry Kissed a Girl! If you wanted a new Commodore, it was a VE and the Ford equivalent was the new FG Falcon.

Another big event of 2008 was the much-anticipated release of AS 4772-2008 Earth-moving machinery – Quick hitches for excavators and backhoe loaders. We all waited anxiously to read how the new Australian Standard would end the semi auto vs fully auto quick hitch debate once and for all. To the despair of machine owners, site controllers and safety geeks alike the definitive answer just didn’t happen. Not only did the new standard not finish the debate the opposite occurred, there was now more to debate and discuss. We even ended up with more types of quick hitches. Now not only do we have semi and fully automatic, we have automatic detach only as well as automatic detach & swing! I was recently asked how this happened, what these new types of quick hitches were and how to determine which one you have.

 

Let’s get back to the standard to work out how this happened and help you determine which hitch you have and therefore how much longer you can use it.

 

The new Australian Standard outlined 2 clear requirements –

1. That there be a primary retention system used to connect/disconnect attachments to the quick hitch

2. A safety system to ensure that the attachment does not unintentionally disconnect from the quick hitch in the event of failure of the primary retention system

Semi automatic hitches meet these requirements (they do however fall down against the legislation and risk assessment process). Many of the fully automatic hitches available have both a primary retention system and a safety system so they must meet these requirements too? It’s true they do however the standard does not require the safety system to act as a “back up” for the primary retention system as is the case with most semi automatic hitches. Many fully automatic hitches have a primary retention system on one side of the hitch and the safety system on the other side. If the primary retention system fails, then the attachment is still connected to the hitch thanks to the safety system. Technically this meets the requirements of the standard however it does allow for the attachment to swing in an uncontrolled manner and this is a problem. Australian legislation requires that all hazards be identified and controlled, uncontrolled movement is a hazard, and, in this case, there is no control of the hazard.

Why didn’t the committee that wrote this new Australian Standard foresee this and manage it in the standard I hear you ask? It is unfair to say they didn’t however the requirement in the standard that was included to manage this possibility is subjective and assumes knowledge of the risk assessment process and the hierarchy of risk control.

 

The standard has the following requirement –

A risk assessment shall be undertaken by the designer and manufacturer before completing the design and manufacture of the quick hitch …………… Any uncontrolled movement caused by the failure of the primary retention system should be considered in the risk assessment.

SafeWork NSW have been very proactive in the quick hitch space for many years now. I have written articles previously explaining their position and their position is included in Plant Assessor when completing risk assessments for NSW and the other states and Territories that support the NSW position. They have introduced the terms Automatic – swing and detach and Automatic – detach only as a result of manufacturers making quick hitches that allow for uncontrolled movement.

 

SafeWork NSW definitions –

Automatic – detach only – Prevents attachments falling off but does not prevent swinging in the event the primary system fails or loses its retention force.

Automatic – detach and swing – Prevents falling off and swinging in the event the primary system fails.

For full information on NSW's current requirements for quick hitches, see our latest guidance on this topic AS13031:2023 Earthmoving machinery - Quick couplers - Safety (ISO13031:2016 MOD)

 

If you have any technical queries, please send them through so that we can provide an answer for you. 

 

Disclaimer: This information is intended to provide general information on the subject matter. This is not intended as legal or expert advice for your specific situation. You should seek professional advice before acting or relying on the content of this information.