The ADR 62 / VSB-1 mandatory compliance confirmation must cover, not just the A-frame members, but
also the welding of the A-frame members to both the chassis and the coupling mounting plate.
Concerns have been raised regarding the use of calculations or FEA (finite element analysis) as a
means of reliably demonstrating compliance with the legal requirements.
Are all existing Engineering Certificates still legal for today's 'vans? Have the dimensions and grades of
the steel used for the A-frames and chassis members been changed?
To over-come these concerns, a physical strength test on the "worst-case" chassis assembly will clearly
demonstrate compliance, or not.
The "worst case" is the highest ATM Rating, the longest, lowest-grade (weakest) and slimmest (smallest
section modulus) members, and the smallest welds.
CCA-accredited engineers will soon have available, a mobile strength-test
unit, that is able to be towed to manufacturers' premises, to enable physical strength tests to be conducted.
The chassis assembly to be tested, is loaded onto, and secured to, the high-strength mobile chassis rig.
The physical tests - with specified forces applied through the centre of the coupling - are:
•
1: Longitudinal - Forward & Rearward
•
2: Lateral (in either direction)
•
3: Vertical - Upward & Downward.
The structural members - and welds - are then examined to determine if they have satisfactorily withstood the tests.
If desired, the forces can then be increased until there is a structural failure, so as to confirm the Safety
Factor provided.
Please contact the CCA - in strict confidence - for more details on having ADR 62 / VSB-1 strength tests
conducted.
Regards
Colin
Manager & Professional Automotive Engineer
{Member: IEAust; SAE; IAME}
Caravan Council of Australia
www.caravancouncil.com.au
[email protected]
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