Vehicle Standard (Australian Design Rule 62/01 – Mechanical Connections Between Vehicles) 2006 I, JAMES ERIC LLOYD, Minister for Local Government, Territories and Roads, determine this vehicle standard under subsection 7 (1) of the Motor Vehicle Standards Act 1989. Dated 26 April 2006 [SIGNED] James Eric Lloyd Minister for Local Government, Territories and Roads
CONTENTS 1. legislative provisions............................................................................ 3 1.1. NAME OF STANDARD..................................................................................... 3 1.2. COMMENCEMENT.......................................................................................... 3 1.3. REPEAL.............................................................................................................. 3 2. FUnction and SCOPE................................................................................. 3 3. APPLICABILITY AND IMPLEMENTATION................................................... 3 4. DEFINITIONS.................................................................................................... 4 5. general application REQUIREMENTS................................................. 4 6. fIFTH WHEEL ASSEMBLIES........................................................................... 5 7. KINGPINS.......................................................................................................... 5 8. AUTOMATIC PIN COUPLINGS...................................................................... 5 9. BALL COUPLINGS........................................................................................... 6 10. cOUPLING BODIES FOR BALL COUPLINGS............................................... 6 11. HOOK COUPLING............................................................................................ 6 12. ‘COUPLINGS’ OTHER THAN THE ABOVE TYPES....................................... 6 13. ‘TOWBAR’ REQUIREMENTS............................................................................ 8 14. ‘DRAWBAR’ REQUIREMENTS....................................................................... 10
1. legislative provisions 1.1. NAME OF STANDARD 1.1.1. This Standard is the Vehicle Standard (Australian Design Rule 62/01 – Mechanical Connections Between Vehicles) 2006. 1.1.2. This Standard may also be cited as Australian Design Rule 62/01 — Mechanical Connections Between Vehicles. 1.2. COMMENCEMENT 1.2.1. This Standard commences on the day after it is registered. 1.3. REPEAL 1.3.1. This Standard repeals each vehicle standard with the name Australian Design Rule 62/01 — Mechanical Connections Between Vehicles that is: (a) made under section 7 of the Motor Vehicles Standard Act 1989; and (b) in force at the commencement of this Standard. 1.3.2. This Standard also repeals each instrument made under section 7 of the Motor Vehicles Standard Act 1989 that creates a vehicle standard with the name Australian Design Rule 62/01 — Mechanical Connections Between Vehicles, if there are no other vehicle standards created by that instrument, or amendments to vehicle standards made by that instrument, that are still in force at the commencement of this Standard. 2. FUnction and SCOPE 2.1. The function of this Australian Design Rule is to specify requirements for devices for mechanical connections between vehicles and their fitment. 2.2. This rule is only applicable to vehicles fitted with ‘Couplings’ which are designed to be separated in normal operation. 2.3. The requirements of this rule do not apply to connection devices mounted at the front of a motor vehicle or devices not intended for towing trailers. 2.4. Fitment of ‘Couplings’ is: 2.4.1. mandatory for all trailers for the ‘Couplings’ which connect to the towing vehicle, and 2.4.2. optional for all other vehicles, but where fitted, must comply with the relevant requirements of this rule. 3. APPLICABILITY AND IMPLEMENTATION 3.1. This rule applies to the design and construction of vehicles as set out in the table below.
3.2. Applicability Table
Vehicle Category
ADR Category Code
UNECE Category Code
Manufactured on or After
Acceptable Prior Rules
Moped 2 wheels
LA
L1
1 Mar 1998
Nil
Moped 3 wheels
LB
L2
1 Mar 1998
Nil
Motor cycle
LC
L3
1 Mar 1998
Nil
Motor cycle and sidecar
LD
L4
1 Mar 1998
Nil
Motor tricycle
LE
L5
1 Mar 1998
Nil
Passenger car
MA
M1
1 Jan 1998
Nil
Forward-control passenger vehicle
MB
M1
1 Jan 1998
Nil
Off-road passenger vehicle
MC
M1
1 Jan 1998
Nil
Light omnibus
MD
M2
1 July 1998
Nil
Heavy omnibus
ME
M3
1 July 1998
Nil
Light goods vehicle
NA
N1
1 July 1998
Nil
Medium goods vehicle
NB
N2
1 July 1998
Nil
Heavy goods vehicle
NC
N3
1 July 1998
Nil
Very light trailer
TA
O1
1 Jan 1998
Nil
Light trailer
TB
O2
1 Jan 1998
Nil
Medium trailer
TC
O3
1 July 1998
Nil
Heavy trailer
TD
O4
1 July 1998
Nil
4. DEFINITIONS 4.1. Refer to Vehicle Standard (Australian Design Rule Definitions and Vehicle Categories) 2005. 5. general application REQUIREMENTS 5.1. ‘Couplings’ designed for separation in normal operation for use between tow vehicles and trailers with an ‘ATM’ up to 3.5 tonnes must be ‘Quick Release Couplings’. 5.2. ‘Couplings’ must not be fitted to the rear of ‘Pig Trailers’ with an ‘ATM’ over 3.5 tonne. 5.3. The ‘Tow Coupling Overhang’ must not exceed: 5.3.1. in the case of an NC vehicle designed for use in ‘Road Trains’, 2.7m; 5.3.2. in the case of a trailer designed for use in ‘Road Trains’ other than a ‘Semi - trailer’, 30 percent of the distance from the centre of the front ‘Axle Group’ to the centre of the rear ‘Axle Group’; 5.3.3. in the case of a ‘Semi - trailer’ designed for use in ‘Road trains’,30 percent of the distance from the ‘Point of Articulation’ to the centre of the rear ‘Axle Group’.
6. fIFTH WHEEL ASSEMBLIES 6.1. ‘Fifth Wheel Assemblies’ must comply with Australian Standard 1773 - 1990 "Articulated Vehicles Fifth Wheel Assemblies" or as amended from time to time. 6.2. ‘Fifth Wheel Assemblies’ must be mounted in conformity with the requirements of Australian Standard 1771 - 1987 "Installation of Fifth Wheel and Turntable Assemblies" or as amended from time to time. 7. KINGPINS 7.1. Kingpins must comply with Australian Standard 2175 - 1995 "Articulated Vehicles - Kingpins" or as amended from time to time. 7.2. Kingpins must be attached to the ‘Semi-Trailer’ ‘Skid Plate’ in conformity with the requirements of Australian Standard 2175-1995 “Articulated Vehicles-Kingpins" Appendix D or as amended from time to time. 7.3. ‘Skid Plate’ of ‘Semi-Trailers’ in TD category must comply with Australian Standard 4235 - 1994 “Articulated Vehicles - Design criteria for fifth wheel skid plates” or as amended from time to time. 7.3.1. ‘Skid Plate’ assemblies must be designed so that provision is made for draining water from the space above the ‘Skid Plate’. 7.4. Notwithstanding the requirements of clauses 7.1 - 7.3, the kingpin dimensional requirements for other than M rated kingpins (as per AS2175-1995) need only comply with Figures 1a or 1b. 8. AUTOMATIC PIN COUPLINGS 8.1. ‘Automatic Pin Couplings’ must comply with: 8.1.1. Australian Standard 2213 - 1984 "50 mm Pin-type Couplings and Drawbar Rings for Trailers" or as amended from time to time except height requirements (clause 2.4) of AS 2213 - 1984; or 8.1.2. ISO 8755 - 1986 "Mechanical connections between towing vehicles and trailers - 40 mm drawbar coupling” and ISO 8718 - 1988 “Commercial road vehicles-Drawbar couplings and eyes for hinged drawbars-Strength test” or as amended from time to time. 8.2. Rear tow ‘Couplings’ fitted to vehicles designed for use in ‘Road trains’ must be 50 mm ‘Automatic Pin Couplings’. 8.3. For rigid ‘Drawbar’ ‘Pig Trailers’ with an ‘ATM’ over 3.5 tonne using ‘Automatic Pin Couplings’, either: 8.3.1. The ‘Coupling’ manufacturer’s ‘ATM’ rating specified for use with rigid ‘Drawbar’ ‘Pig Trailers’ must not be exceeded; or 8.3.2. the ‘Automatic Pin Couplings’ must be ‘D-value’ and ‘V-value’ rated as determined using the test requirements of Clauses 12.3.3.2 where: 8.3.2.1. the ‘V - value’ is at least: ‘V-value’ in kN = 2.4(x/1)2C where C = ‘ATM’ of ‘Pig Trailer’ in tonne x = the length of the loading area of trailer, in metres as shown in Figure 2. l = the length of the drawbar, in metres as shown in Figure 2. Note: (x/1)2 > 1 in all cases 9. BALL COUPLINGS 9.1. ‘Ball Couplings’ intended for towing trailers up to 3.5 tonnes ‘ATM’ must comply with Australian Standard 4177.2 - 1994 "50 mm Towballs" or as amended from time to time. 10. cOUPLING BODIES FOR BALL COUPLINGS 10.1. The coupling body of a 50 mm ‘Ball Coupling’ intended for trailers up to 3.5 tonnes ‘ATM’ must comply with Australian Standard 4177.3 - 1994 "Coupling Body for Ball Couplings" or as amended from time to time. 11. HOOK COUPLING 11.1. The hook part of the ‘Hook Coupling’ must be suitable for use with the towing ring as shown in Figure 3. 11.2. The towing ring must comply with Figure 3. 11.3. ‘Hook Couplings’ must also comply with Clauses 12.2 - 12.4 except for clause 12.4.3.2. 12. ‘COUPLINGS’ OTHER THAN THE ABOVE TYPES 12.1. ‘Couplings’ other than ‘Fifth Wheel Assemblies’, Kingpins, ‘Automatic Pin Couplings’, ‘Ball Couplings’, Coupling Bodies for 50mm Ball Couplings and ‘Hook Couplings’ must comply with the ‘Coupling’ manufacturer’s location specification and Clauses 12.2 - 12.4. 12.2. Locking Mechanism Requirements 12.2.1. ‘Couplings’ must incorporate a positive locking mechanism together with a separate means of retaining this mechanism in the locked position. The locking must be readily verifiable by visual examination. 12.2.2. ‘Quick Release Couplings’ must incorporate a positive locking mechanism together with a separate means of automatically retaining this mechanism in the locked position. The locking must be readily verifiable by visual examination. 12.3. Strength Requirements 12.3.1. ‘Couplings’ specially designed for use between LA, LB, LC, LD category and LEM sub category towing vehicles and trailers up to 750Kg ‘ATM’ when installed in the design configuration must withstand the test requirements as per either clause 12.3.1.1 or clause 12.3.1.2 without either incurring any residual deformation that would interfere or degrade the function of the assembly or any breaks, cracks or separation of components and shall have a capacity to tow trailer of 750Kg ‘ATM’. 12.3.1.1. the following separately applied static forces: 12.3.1.1.1. longitudinal tension and compression of 18.4 kN; and 12.3.1.1.2. vertical tension and compression of 7.4 kN; and 12.3.1.1.3. transverse tension and compression of 7.4 kN. 12.3.1.2. A minimum horizontal alternating force of ± 2.52 kN acting in a line parallel to the ground and in the longitudinal median plane of the towing vehicle passing through the centre of the coupling applied for 2 million cycles. The frequency of the longitudinal forces not to exceed 35Hz, but must be chosen not to coincide with any natural frequency of the system. 12.3.2. ‘Couplings’ specially designed for use between towing vehicles and trailers up to 3.5 tonnes ‘ATM’ when installed in the design configuration must withstand the test requirements as per either clause 12.3.2.1 or clause 12.3.2.2 without either incurring any residual deformation that would interfere or degrade the function of the assembly or any breaks, cracks or separation of components and shall have a capacity to tow trailer of 3.5 tonnes ‘ATM’. 12.3.2.1. the following separately applied static forces: 12.3.2.1.1. longitudinal tension and compression of 86 kN; and 12.3.2.1.2. vertical tension and compression of 35 kN; and 12.3.2.1.3. transverse tension and compression of 35 kN. 12.3.2.2. A minimum horizontal alternating force of ± 12 kN acting in a line parallel to the ground and in the longitudinal median plane of the towing vehicle passing through the centre of the ‘Coupling’ applied for 2 million cycles. The frequency of the longitudinal forces not to exceed 35 Hz, but must be chosen not to coincide with any natural frequency of the system. 12.3.3. ‘Couplings’ specially designed for use between towing vehicles and trailers over 3.5 tonnes ‘ATM’ when installed in the design configuration must withstand the test requirements as per either clause 12.3.3.1 or clause 12.3.3.2 without either incurring any residual deformation that would interfere or degrade the function of the assembly or any breaks, cracks or separation of components. 12.3.3.1. ‘D-value’ rated Dynamic Test Requirements 12.3.3.1.1. A minimum horizontal alternating force of (± 0.6 x ‘Couplings’’ D-value’ ) acting in a line parallel to the ground and in the longitudinal median plane of the towing vehicle passing through the centre of the ‘Coupling’ applied for 2 million cycles. The frequency of the longitudinal forces not to exceed 35 Hz, but must be chosen not to coincide with any natural frequency of the system. 12.3.3.2. ‘D and V-value’ rated Dynamic Test Requirements 12.3.3.2.1. A minimum horizontal alternating force of (± 0.6 x ‘Coupling’
‘D-value’) acting in the longitudinal axis of the ‘Coupling’ and a minimum vertical alternating force of ( static vertical coupling load ± 0.6 x ‘Coupling’ ‘V-value’ ) in the vertical axis of the ‘Coupling’ applied through the ‘Coupling’ centre asynchronously for 2 million cycles each. Static vertical load in kN = g x S where: g = acceleration due to gravity (assumed to be 9.81 m/sec2) S = vertical load in tonnes (‘ATM’ - ‘GTM’) 12.3.3.2.2. The vertical and horizontal components shall be sinusoidal in shape and shall be applied asynchronously where the difference of their frequencies shall be between 1 % and 3 % and not exceed 35 Hz, but must be chosen not to coincide with any natural frequency of the system. 12.4. Marking Requirements 12.4.1. Both parts of the ‘Coupling’ specially designed for use between LA, LB, LC, LD category and LEM sub category towing vehicles and trailers up to 750 Kg ‘ATM’ must comply with the following marking requirements: 12.4.1.1. the ‘Coupling’ manufacturer’s name or trademark; and 12.4.1.2. "750 kg" (ie the maximum allowable trailer ‘ATM’ for which the ‘Coupling’ is rated), 12.4.1.3. the words "Model (model identifier) use with model (model identifier)". 12.4.2. Both parts of the ‘Coupling’ specially designed for use between towing vehicles and trailers up to 3.5 tonne ‘ATM’ must be marked with: 12.4.2.1. the ‘Coupling’ manufacturer’s name or trademark; and 12.4.2.2. "3.5 TONNE" (ie the maximum allowable trailer ‘ATM’ for which the ‘Coupling’ is rated); and 12.4.2.3. the words "Model (model identifier) use with model (model identifier)". 12.4.3. Both parts of the ‘Coupling’ specially designed for use between towing vehicles and trailers over 3.5 tonnes ‘ATM’ must be marked with: 12.4.3.1. the ‘Coupling’ manufacturer’s name or trademark; and 12.4.3.2. the words "Model (model identifier) use with model (model identifier)". 12.4.3.3. either the rated ‘D-value’ and ‘V-value’ or only the’ D-value’ in kN. 12.4.4. All marking to be stamped or moulded must be with letters of not less than 2.5 mm high and must be visible when the coupling is installed and connected. 13. ‘TOWBAR’ REQUIREMENTS 13.1. For vehicles fitted with ‘Towbars’ with a ‘Towbar’ maximum rated capacity: 13.1.1. of up to 3.5 tonne, the ‘Towbar’, towing bracket, towbar attachment and vehicle structure must comply with AS 4177.1 - 1994 "Towbars and towing brackets" or as amended from time to time. 13.1.2. of over 3.5 tonne, the ‘Towbars’, towing bracket, towbar attachment and vehicle structure must conform with the Clauses 13.2 - 13.4. 13.2. ‘Towbars’ Marking Requirements: 13.2.1. Except where the ‘Towbar’ is an integral part of the vehicle the ‘Towbar’ must clearly and permanently display the following information: 13.2.1.1. the ‘Towbar’ manufacturer’s name or trade mark; and 13.2.1.2. the "make and model" shown on the ‘Compliance Plate’ or trailer plate fitted to the vehicle for which it is designed or the manufacturer’s part number; and 13.2.1.3. its maximum rated capacity expressed in numerals not less than 6 mm high. The maximum rated capacity must be the ‘ATM’ in tonnes or the maximum ‘Coupling’ ‘D- value’ in kN for which the ‘Towbar’ is designed and must not exceed the vehicle manufacturer’s rated capacity. 13.2.2. Where the information required in clause 13.2.1 is not visible when the ‘Towbar’ is fitted to the vehicle, an additional plate clearly and permanently marked and in a conspicuous position must be affixed to the vehicle adjacent to the ‘Towbar’ showing the maximum rated capacity of the ‘Towbar’. 13.3. ‘Towbars’ Strength Requirements: 13.3.1. For vehicles other than those designed for use in ‘Road Trains’ and up to 23.5 tonnes ‘ATM’, the vehicle structure including the ‘Towbar’ must withstand loads as per Clause 13.3.1.1 or 13.3.1.2 without incurring either any residual deformation that would interfere or degrade the function of the assembly or any breaks, cracks and separation of components. Alternatively approval can be by calculation as per Clause 13.3.3. 13.3.1.1. the static forces separately applied at the intended ‘Coupling’ centreline: 13.3.1.1.1. longitudinal tension and compression(N) = 1.5 x 9.81 x ‘ATM’ (for which towbar is designed)(Kg); and 13.3.1.1.2. transverse thrust(N) = 0.5 x 9.81 x ‘ATM’ (for which towbar is designed)(Kg); and 13.3.1.1.3. vertical tension and compression(N) = 0.5 x 9.81 x ‘ATM’ (for which towbar is designed)(Kg) 13.3.1.2. A horizontal oscillating force of + 0.6 x the maximum ‘Coupling’ ‘D-value’ marked on the ‘Towbar’ according to clause 13.2.1.3 and a vertical oscillating force of + 0.18 x ‘ATM’ (for which the towbar is designed) for 2 million cycles, applied asynchronously at the intended ‘Coupling’ centreline. The frequency not to exceed 35 Hz and must be chosen not to coincide with any natural frequency of the system. 13.3.2. For vehicles designed for use in ‘Road Trains’ or for vehicles over 23.5 tonnes ‘ATM’, the ‘Towbar’ must withstand loads as per Clause 13.3.2.1 or 13.3.1.2 without incurring either any residual deformation that would interfere or degrade the function of the assembly or any breaks, cracks and separation of components. Alternatively approval can be by calculation as per Clause 13.3.3. 13.3.2.1. the static forces separately applied at the intended ‘Coupling’ centreline: 13.3.2.1.1. the longitudinal tension and compression of 350kN; and 13.3.2.1.2. the transverse thrust of 120kN. 13.3.2.1.3. the vertical tension and compression of 120kN. 13.3.3. The strength of a ‘Towbar’ to withstand the forces of clauses 13.3.1 or 13.3.2 can be demonstrated by ‘Approved’ calculation procedures where the calculations take into account both the strength and fatigue resistance. 13.4. ‘Towbars’ Safety Chain Attachment Requirements 13.4.1. For vehicles other than those designed for use in ‘Road Trains’ , the ‘Towbar’ must be fitted with two safety chain attachments, of strength meeting the requirements of clause 13.4.2, mounted one on either side of, and adjacent to, the tow ‘Coupling’. 13.4.2. Each safety chain attachment provided on the ‘Towbar’ must withstand the following forces without either any residual deformation that may interfere with or degrade the function of the assembly or any breaks, cracks, or separation of components: 13.4.2.1. longitudinal tension(N) = 9.81 x ‘Towbar’s’ rated capacity(Kg); and 13.4.2.2. vertical load (N) = 0.5 x 9.81 x ‘Towbar’s’ rated capacity (Kg). 13.4.3. ‘Towbar’ safety chain attachments must be fixed to a part of the ‘Towbar’ which is permanently attached to the vehicle. 13.4.3.1. Means of permanent attachment include at least either welding or bolting. 14. ‘DRAWBAR’ REQUIREMENTS 14.1. The ‘Drawbar’ must be securely attached to a substantial portion of the trailer. 14.2. The ‘Drawbar’ including the connections between ‘Drawbar’ and trailer must withstand loads as per Clause 14.2.1 or 14.2.2 without incurring either any residual deformation that would interfere or degrade the function of the assembly or any breaks, cracks and separation of components. Alternatively approval can be by calculation as per Clause 14.2.3. 14.2.1. ‘Drawbars’ to withstand a dynamic endurance test for 2 million cycles: 14.2.1.1. ‘Drawbars’ for ‘Pig trailers’ up to 3.5 tonnes ‘ATM’ and hinged ‘Drawbars’ for other trailers to withstand a horizontal oscillating force of ± 0.6 x ‘Coupling’ ‘D-value’ in the longitudinal direction concurrently for 2 million cycles, applied at the intended ‘Coupling’ centreline. The frequency must not exceed 35 Hz, and must be chosen not to coincide with any natural frequency of the system; 14.2.1.2. Rigid ‘Drawbars’ for ‘Pig trailers’ over 3.5 tonnes ‘ATM’, to withstand a minimum horizontal alternating force of (± 0.6 x ‘Coupling’ ‘D-value’) acting in the longitudinal axis of the ‘Coupling’ and a minimum vertical alternating force of (static vertical coupling load ± 0.6 x ‘Coupling’
‘V-value’) in the vertical axis of the ‘Coupling’ applied through the ‘Coupling’ centre asynchronously for 2 million cycles. Static vertical coupling load in kN = g x S where: g = acceleration due to gravity (assumed to be 9.81 m/sec2) S = vertical load in tonnes (‘ATM’ - ‘GTM’) The frequency of the longitudinal and vertical forces must differ by between 1 % and 3 % and not exceed 35 Hz, but must be chosen not to coincide with any natural frequency of the system. 14.2.2. ‘Drawbars’ to withstand a static test: 14.2.2.1. For trailers other than ‘Convertor Dollies’ and up to 23.5 tonnes ‘ATM’ the following minimum static forces separately applied at the intended ‘Coupling’ centreline: 14.2.2.1.1. longitudinal tension and compression(N) = 1.5 x 9.81 x ‘ATM’(Kg); and 14.2.2.1.2. transverse thrust (N)= 0.5 x 9.81 x ‘ATM’(Kg); and 14.2.2.1.3. except for hinged ‘Drawbar’ trailers vertical tension
and compression(N) = 0.5 x 9.81 x ‘ATM’(Kg); 14.2.2.2. For ‘Convertor Dollies’ or trailers over 23.5 tonnes ‘ATM’, the following minimum static forces separately applied at the intended ‘Coupling’ centreline: 14.2.2.2.1. longitudinal tension and compression = 350kN; and 14.2.2.2.2. transverse thrust = 120kN; and 14.2.2.2.3. except for hinged ‘Drawbar’ trailers vertical tension and
compression = 120kN 14.2.3. The strength of a ‘Drawbar’ can be demonstrated for loads as per clause 14.2.2 by ‘Approved’ calculation procedures where the calculations take into account both strength and fatigue resistance. 14.3. ‘Drawbars’ Safety Chain Attachment Requirements. 14.3.1. Safety chains must be permanently attached to the trailer. 14.3.1.1. Shackles are not permitted. 14.3.2. For trailer up to 3.5 tonnes ‘ATM’, the safety chain attachment can be by welding. 14.3.2.1. the weld must extend around 50% of the circumference of the link and the adjoining link must have free movement. 14.3.3. For trailer over 3.5 tonnes ‘ATM’ safety chain attachment must not involve welding or deformation of the chain. 14.3.4. The safety chain attachment must be located as near as practicable to the ‘Coupling’ and where 2 points of attachment are required they must be mounted one on either side of the centreline of the ‘Drawbar’. 14.3.5. The safety chain attachment must withstand the following minimum forces, separately applied, without incurring either any residual deformation that would interfere or degrade the function of the assembly or any breaks, cracks or separation of components: 14.3.5.1. longitudinal tension(N) = 9.81 x ‘ATM’(Kg); and 14.3.5.2. vertical load (N) = 0.5 x 9.81 x ‘ATM’ (Kg). 14.4. Safety Chain Requirements 14.4.1. Safety chains must be affixed to a substantial portion on every trailer which is not fitted with an ‘Emergency Brake System’ in accordance with the Australian Design Rule 38/02 "Trailer Brake Systems", and on every ‘Drawbar’ of a Rigid drawbar Trailer except a ‘Converter Dolly’. 14.4.1.1. Trailers having an ‘ATM’ over 2.5 tonnes must be fitted with 2 safety chains for connection to the towing vehicles. Each safety chain must meet separately the strength requirements of clause 14.4.2 or 14.4.3. 14.4.2. For trailers up to 3.5 tonnes ‘ATM’, the safety chain must comply with Australian Standard 4177.4 -1994 "Safety Chains up to 3500 kg" or as amended from time to time. 14.4.3. For trailers over 3.5 tonnes ‘ATM’, the safety chain must be made from steel of a minimum 800 MPa breaking stress and conform to the mechanical properties of Grade T chain as specified in Australian Standard 2321-1979 "Short Link Chain for Lifting Purposes (non-calibrated) or as amended from time to time; and must be of a size corresponding with the ‘ATM’ of the trailer shown in Table 1.
‘Aggregate Trailer Mass’ (tonnes)
Chain Size (millimetres)
Minimum Chain Breaking Load (tonnes)
Over 3 .5 and up to 4.3
7.1
6.4
Over 4.3 and up to 7.5
9.5
11.6
Over 7.5 and up to 13.5
12.7
20.4
Over 13.5 and up to 21.5
15.9
32.0
Over 21.5 and up to 30.0
19.0
46.4
Over 30.0
22.0
63.2
Table 1: Safety Chain Size Selection
Figure 2 Figure 3
