Heavy vehicle recognised engineering signatories

This page provides information on recognised engineering signatories (RES) for heavy vehicle modifications. A heavy vehicle is defined as having a gross vehicle mass (GVM) greater than 4.5 tonnes or a trailer with a gross trailer mass (GTM) greater than 4.5 tonnes.

Many modifications to a heavy vehicle, including trailers, will need to be completed in accordance with the National Heavy Vehicle Regulator (NHVR) Code of Practice for the Approval of Heavy Vehicle Modifications, published by the NHVR, Vehicle Standards Bulletins, the specifications and guidance of the original vehicle manufacturer, other relevant standards, or a combination of these.

Modifications completed that fall within the NHVR Code of Practice for the Approval of Heavy Vehicle Modifications and carried out in accordance with Heavy Vehicle National Law, section 86 must be carried out under the direction of a RES who will submit a report of the changes made to the vehicle for approval by the Department for Infrastructure and Transport (DIT). Where a modification is not in accordance with the NHVR Code of Practice for the Approval of Heavy Vehicle Modifications, Vehicle Standards Bulletins or the specifications and guidance of the original vehicle manufacturer and carried out in accordance with Heavy Vehicle National Law, section 87, a Modification Application must be submitted to the NHVR for the specific approval of the proposed modification before beginning the modification work.

RES are individuals recognised by the DIT in South Australia, and acting according to the Manual for the Recognised Engineering Signatory Heavy Vehicle Modification Scheme.

The first table lists all recognised engineering signatories in South Australia along with their recognised fields of work. The second and third tables describe the approval codes.

Table 1. Recognised engineering signatories

Table 2. Approval codes

A1 - Engine substitution
A2 - Air cleaner substitution or additional fitting
A3 - Turbocharger installation
A4 - Exhaust system alteration
A5 - Road speed limiter installation
B1 - Transmission substitution or additional fitting
C1 - Tail shaft modification
D1 - Rear axle(s) installation
D2 - Differential substitution
D3 - Fitting of non-standard rear wheel components
E1 - Front axle(s) installation
E2 - Steering alteration
E3 - Fitting of non-standard front wheel - ie tyre or rim
F1 - Suspension substitution
F2 - Trailer suspension modifications
G1 - Air brake system - relocation of air brake components
G2 - Installation of trailer brake controls: air brakes
G3 - Trailer brake system upgrade
G4 - Brake system certification
G5 - Auxiliary brakes - engine, exhaust, or retarder type
G6 - Air-operated accessories
G7 - Brake system substitution or wheelbase extension
G8 - Trailer brake system upgrading approved design certification for non-standard
H1 - Trailers wheelbase extension outside the first manufacturer’s option
H2 - Wheelbase reduction outside the first manufacturer’s option
H3 - Wheelbase alteration within first manufacturer’s option
H4 - Chassis frame alteration
H7 - Design or manufacture of aftermarket front under-run protection
J1 - Body Mounting
J2 - Truck bus body fitment
J3 - Fitting of a roll-over or falling object protection system
J4 - Tipper bodies 
K1 - Seating capacity alteration, seat, seat belt, and anchorage installation
K2 - Seat anchorage certification and seat belt anchorage certification
K3 - Cabin conversion
K5 - Wheelchair occupant restraint system installation
K6 - Child restraint anchorage installation
M1 - Fuel system alterations
P1 - Tow coupling installation - vehicles over 4.5 t GVM
P2 - Fifth wheel and king pin installation
R1 - Installation of vehicle-mounted lifting system
R2 - Wheelchair loader installation
S1 - Gross vehicle and gross combination mass rating to S2 or S3 approved design or within Manufacturer’s Specification
S2 - Gross Vehicle Mass Rating Approved Design Certification for Non-Standard Vehicles or Special Vehicles
S3 - Gross Combination Mass Rating Approved Design Certification for Non-Standard Vehicles
S7 - Aggregate Trailer Mass Rating to S12 Approved Design or Within Manufacturer’s Specification
S8 - Road Train Prime Mover Rating
S9 - B-Double Prime Mover Rating
S11 - Road Train Trailer Rating
S12 - Aggregate Trailer Mass Rating Approved Design Certification for Non-Standard Trailers
T1 - Construction of Tow Trucks
T2 - Design of Tow Trucks

Table 3.  Other codes

Recognised engineering signatories can also manage the procedures for a heavy vehicle that does not have an identification plate fitted.

Z1 - No AMVCB or Motor Vehicle Standards Act identification plate fitted - plate missing
Z2 - No AMVCB or Motor Vehicle Standards Act identification plate approval