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Tag axle fitment

Adding a tag axle to a chassis.

Vehicle Characteristics
For all cases
Method of Inspection
  • Static brake tests
  • Rolling road test
  • AUC graph 1B
  • AUC graph 2 or3 (as applicable)
  • Full dynamic test

Vehicle Characteristics
If a test report is available for a similar source vehicle (same wheel-brakes, tyres and axle masses, with identical tag axle),
but with a different wheelbase
Method of Inspection
  • Static brake tests
  • Rolling road test
  • AUC graph 1B
  • AUC graph 2 or3 (as applicable)
  • Dynamic test type O only

Vehicle Characteristics
Modifications outside OEM’s envelope and possible changes to air system other than extending or shortening air-pipes and/or additional fitment of trailer connections or other components
Method of Inspection
  • OEM’s envelope
  • Static inspection
  • Rolling road test
  • AUC graphs 1B
  • AUC graph 2 or 3 (only if towing unit)
  • Dynamic test type 0 unladen

Notes:
Fitment of an additional axle (Tag axle)
The fitment of an additional axle it will change the vehicle configuration and increase the design mass (GVM). All tests must be done with the new GVM.
TheOEM’s declaration of non-ojection in writing must be available, stating any possible restrictions or limitations

Dynamic testing required if:
  • No records are available for the fitment of such an additional axle to a source vehicle of the same build.
    An additional axle of different make or brake characteristic is fitted.


Limited dynamic testing (Type O tests only) will be required if:
  • The vehicle of same or similar design (identical running gear throughout) has previously been built (e.g. leading or trailing tag axle)


No dynamic testing will be required if:
  • A vehicle is built up to existing OEM’s specifications using original OEM’s parts and building it to the same level as provided in a certificate from the OEM or converter.




Please keep in mind that the regulator may at any time apply their own interpretation before issuing a NaTIS certificate.