VSB6 Modification Code J4 – Tipper bodies

This consultation closed on 19 October 2021. The NHVR would like to thank everyone who took the time to provide feedback.

Key documents 

Please note: This is a consultation draft only. Before the final document is published, the NHVR will be undertaking a full quality assurance process, including proof reading, insertion of appropriate images and diagrams, and final reformatting. These documents are drafts only and may be changed following feedback provided during public consultation. The drafts are not to be regarded as an authorised standard until approved and issued by relevant heavy vehicle regulators.

What is it?

Modification code J4 sits within Section J: Body Mounting requirements of Vehicle Standards Bulletin 6 (VSB6) and provides design requirements for modification of a motor vehicle by fitting a tipper body.

It provides a practical modification code that should allow tippers to both operate safely on the road while also allowing them to perform their required tipping functions.

Design requirements have been developed to ensure vehicles operate safely on road while meeting minimum safety standards for the tipping system.


An extensive review of the existing tipper requirements in the J1 modification code along with how these vehicles are currently designed and operated has been conducted. This review lead to the development of the proposed modification code J4 and has included input from peak industry, tipper manufacturers and jurisdictional WH&S departments.

From the outcome of this review the new modification code J4, provides both required and recommended standards for the AVE to follow when fitting a tipping body to a heavy vehicle.

Why we’re consulting

The new J4 modification code provides requirements specific to tippers which may result in updates to tipper designs that are currently being certified under the J1 modification code.

Additionally, the proposed introduction of the J4 modification code impacts how modifications are certified under section J.

Previously, the modification of a motor vehicle to a tipper was covered under the J1 modification code. While this code provided some tipper specific requirements, the J1 code is a generalised code that provides generic advice for the fitment of a body to a heavy vehicle. To reduce cost and increase flexibility for industry it is proposed that the J2, J3 and new J4 transition to a two-stage design-modification approach.

Under this approach, a design approval for the truck-bus bodies, ROPS/FUPS devices and tipper bodies, which would include installation instructions, would be issued by an engineer qualified approved vehicle examiner (AVE) for a make and model of vehicle. An approved truck body, ROPS/FUPD device or tipper body could then be installed on a vehicle in accordance with the approved design and installation instructions by a J1 Accredited AVE, providing significantly greater flexibility to the operator.

Providing feedback

Submissions closed on 19 October 2021.