Einstein quoted insanity as doing the same thing over and over and expecting to get different results.
Sounds like a lot of government departments! But there can good in this, especially if it relates to safety and results continue to providing safe outcomes.
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Everybody has a story of doom and gloom, fewer with hope.
Case 1: Many years back within a couple of weeks of starting a new job, the chief engineer said “come for a walk with me”. The sight was sad, a near new tipping truck with the body stuck in the up position, both chassis’ rails bent down at about 60 degrees at the rear spring hangers. The chief wanted answers as to why this happened!
Case 2: More than 20 years ago, I was approached by a dealer principal regarding a problem they were having with rigid trucks in a certain application, with continuing chassis failures, a design and installation endorsed by the OEM.
The Australian Design Rules, Australian Vehicle Standards Rules, vehicle modification guidelines and similar standards are supposedly in the interest of safety. But there are some who think that platforms such as the ADRs should be used to protect manufacturing and the like.
The issues around approving heavy vehicle modifications hasn’t changed much over many years, there are those engineers who do a very thorough job assessing modifications whilst there continues to be examples of approved modifications that don’t confirm to OEM guidelines or Vehicle Standards Bulletin No: 6.
Yet the signatory authorisation and modification approval process is supposed to ensure a common standard, level playing field, can often fail.
Body mounting and especially tipping bodies have been a source for innovation and creativity, rear side and even three-way tippers. I recall one example of a rigid body where the chassis had a hole cut through it, for the underbody exhaust to pass through it and the OEM was pretty excited about all of this. Which raises the question, how does this sort of stuff get through any sort of engineering Standards system?
The recent changes to Section “J” and Section “J4” has caused much angst within some of the approved AVE’s. It has often been suggested that there is a major disconnect between ADRs and VSBs. In reference to J4, manufacturers who provide a completed vehicle to the market, eg: a rigid vehicle with a tipping body, do not have to meet the same installation requirements as an AVE conforming to Section J4.
But there is a twist, this same vehicle then goes to ZYX Engineering for a towbar fitment, that requires AVE Certification! Are the original vehicle components including the tipping body fitment then subject to further inspection and re-certification? At least AVE cannot get a straight answer from the NHVR.
If an OEM can fit a tipping body (at the factory or wherever, pre-compliance certification) and be approved as complying for registration, then why does an AVE have to comply to/with a differing standard?
There is no suggestion that there are engineering issues with Section J; some opinions are complimentary, whilst others less so. But why wouldn’t a tipping body of exactly the same specifications, fabrication and mounting geometry etcetera fitted to the same chassis after certification be acceptable?
VSB6 mandates a tipping body support prop (for safety) but the design requirement is only when the tipping body is unladen. If a manufacturer designs, builds and certifies a tipping truck or trailer, the ADRs do not mandate any requirement for a tipping body support prop. Though safety logic would hopefully ensure otherwise.
There are known examples of imposed chassis stresses at the initial tipper ‘lift-off’ being higher than in the normal travel configuration; and, if a tipping body experiences a load ‘hang-up’ again the allowable chassis stresses may also be exceeded. VSB6 doesn’t explicitly raise these issues, so how is the AVE expected to be across all issues?
Regulatory and legislative bodies are in conflict. The NHVR through VSB6 applies requirements that are not applicable to the ADRs. So, OEM factory tipper bodies, are covered by the Federal Road Vehicle Standards Act (RVSA), and VSB6 does not apply.
The NHVR does not have powers to require compliance with VSB6 for new vehicles where it is covered by a Vehicle Approval, however the NHVR quotes that it does recommend that OEM tipper vehicles comply with VSB6.
A further issue is the situation where VSB6 requirements are not consistent with either ADRs or original vehicle manufacturer’s guidelines; then the ADRs or the manufacturer’s guidelines, if available, override those of VSB6.
However, the complications with Checklist J4 continue:
Has the modification been performed in accordance with the manufacturer’s guidelines (body builders guide)?
Does this design meet the requirements of the manufacturer’s guidelines?
Other than modification criteria, if the answer to any relevant question is NO the modification is not acceptable.
So confusion begins, if the modification is in accordance with manufacturers guidelines but not in accordance with Code J4, the authorization cannot be accepted; yet VSB6 introduction states that the manufacturer’s guidelines override VSB6.
The practice of AVEs, working to a Code controlled by the NHVR (that sounds good – the National part of National Heavy Vehicles) but the AVE’s are controlled by the states/territories so out goes the consistent approach to a National Standard. The states often introduce/allow additional requirements and the NHVR is a lame duck in addressing.
There is good reason why engineering supports change amongst failure.
Case 1: The chassis simply wasn’t up to the task of supporting the laden tipping body with a product hang-up. The overhung bending moment and resultant stress grossly exceeded the maximum for the chassis rail section. Time for analytical change.
Case 2: After inspecting a couple of the vehicles, I had a reasonable ‘gut feel’ as to problem.
Then having completed sheer force and bending moment calculations I advised the Dealer Principal “the chassis is failing exactly where it should” – he didn’t think that was very funny.
A redesign of the sub-frame to distribute point loads solved the issue.
If we do the same thing over and over, with a good and proven design, then we should get the same result, years of safe service without issue.
VSB6 was first printed in 1993 by the then Federal Office of Road Safety. It’s a matured document, but there is always scope for improvement! A little tweaking here and there would be a benefit.
The person who never made a mistake never made anything, and a broader concern is, it’s hard for persons to bring practical end user experience to rule making when they have never built anything.
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