Land Transport Rule

Heavy-vehicle Brakes 2006

Rule 32015

This is Schedule 3 of the Heavy-vehicle Brakes Rule.

 

Schedule 3     Heavy Vehicle Brake Code, First edition 1991

Vehicle standards
Land Transport Division
Ministry of Transport
ISBN 0-477 05252-5

 

Acknowledgement

The Ministry of Transport gratefully acknowledges the very substantial contributions made by the Chairman and members of the Heavy Vehicle Brake Code Committee, individually and collectively, in the preparation of this code and for the support given to committee members by their respective employers.

The Ministry is also indebted to the various organisations that have made vehicles, equipment and services available and without whose support, the production of this code would not have been possible.

©1991 Land Transport Division

Ministry of Transport
P O Box 27-459
Wellington
New Zealand
Phone (04) 828-300 Fax (04) 855-699

 

Contents

Preface

1.0     Scope and interpretation

2.0     Definitions

3.0     Compliance

4.0     Specifications

5.0     Exemptions for power driven vehicles which are equipped to tow trailers.

Appendices

A.     Distribution of braking among the axles of vehicles and requirements for compatibility between drawing vehicle and trailer.

B.     Requirements for measuring the response time on vehicles equipped with compressed-air brakes.

C.     Statement of compliance with the New Zealand Heavy Vehicle Braking Code.

D.     Pressure test connections for air-braking systems

E.     Maximum axle weights

F.     Provisions relating to energy sources and energy storage devices.

 

Preface

Background to the New Zealand situation

In New Zealand, power driven vehicles are sourced from world markets, the majority coming from Europe, North America, Japan and Australia. The result is that the local powered vehicle population has variations of the braking systems common to the country of origin. Locally manufactured trailers generally use imported brake components and are only required to meet emergency stop and parking performances.

By legislation, New Zealand has lower individual axle loadings than are common in the countries from which the power driven vehicles and trailer components are sourced. The road tax on heavy vehicles is collected through a system known as Road User Charges and applies to vehicles over 3500 kg gross weight. It is allocated according to gross vehicle mass, axle configuration and distance travelled. This tax has created a situation unique to this country by encouraging operators to fit more axles to carry a given load than would otherwise be necessary. Braking problems therefore can arise because the axles used on these vehicles are designed for substantially higher loadings and are fitted with brakes sized accordingly.

 

The Code

This code has been developed to improve the braking performance of heavy vehicles in New Zealand by an industry based committee consisting of representatives from the MVMA, NZRTA, IRTENZ, DSIR, NZTTMF and MOT.The code is based on European brake performance requirements, namely the United Nation Economic Commission of Europe Regulation 13, (ECE 13). To facilitate its adoption into the brake code, some simplifications to the regulation have been made and special New Zealand requirements have been included. Every effort has been made to minimise the extent of modifications necessary or existing vehicles to meet the code requirements.

It is intended to Gazette this code as an acceptable alternative (under Regulation I6A(2) of the Heavy Motor Vehicle Regulations 1974) to the current Heavy Vehicle Braking Specification, effective from 1 July 1991, for vehicle combinations operating at more than 39 000 kg. The further intention, is that all vehicles with a gross mass exceeding 3500 kg, first registered after 1 July 1994, will have to comply with ECE 13 plus special New Zealand annexes; or an equivalent international regulation if developed in the meantime. As a minimum requirement, any vehicle used in combination with a new vehicle first registered after 1 July 1994, shall comply with this code.

 

Aims of the Code

The aim of this code is to improve heavy vehicle safety by standardising braking performance. Its provisions can be summarised as follows:

 

Auxiliary brake equipment

The code sets out general guide lines for supplementary brake equipment that gives the driver greater control and improved brake performance. This equipment includes such items as, trailer hand control, anti-lock braking systems (ABS), load sensing devices and engine retarders. The addition of any of this equipment to a certified vehicle will be classed as a modification and will require the vehicle to be recertified.

 

1.0     Scope and interpretation

This code applies to the braking of vehicles with a gross vehicle mass of more than 3500 kg. It applies to power driven vehicles individually and to trailers individually.

In this code the words ‘shall’ or ‘must’ indicate a requirement that is to be adopted in order to comply with the code, while the word ‘should’ indicates a recommended practice.

 

2.0     Definitions

2.1     General

2.1.1     ‘Certifier’ means manufacturer, a group or a person who are recognised by the Statutory Authority as being experienced in the matter of Heavy Vehicle Braking.

2.1.2     ‘Drawing vehicle’ means a vehicle equipped to tow a trailer.

2.1.3     ‘Gross Vehicle Mass (GVM)’ means the maximum laden mass of a motor vehicle as specified by the manufacturer or the New Zealand regulations, whichever is the lesser. See Appendix E.

2.1.4     ‘Gross Combination Mass (GCM)’ means the sum of the GVMs of the drawing vehicle and trailers) used in a combination. It is the lesser of that specified by the manufacturer of the drawing vehicle or the New Zealand regulations.

2.1.5     ‘Manufacturer’ means an organisation acceptable to the Statutory Authority, engaged in the manufacture, assembly, or importation of vehicles with a GVM of more than 3500kg.

2.1.6     ‘Statutory authority’ means the Secretary for Transport or persons with authority duly delegated by the Secretary for the purposes of this code.

2.1.7     ‘Vehicle type’ means a category of vehicles which do not differ in such essential respects as:

2.1.8     Unladen mass means the mass of the vehicle fitted with body and equipment, plus full fuel tanks.

 

2.2     Trailer definitions

2.2.1     ‘Trailer’ means a towed vehicle.

2.2.2     ‘Full trailer’ means a towed vehicle fitted with at least two axle sets, and equipped with a drawbar which controls the direction of the front axle(s) and which transmits no significant static load to the drawing vehicle.

2.2.3     ‘Semi-trailer’ means a towed vehicle having one axle set positioned behind the centre of gravity of the vehicle (when fully laden) so that a substantial portion of the laden vehicle’s weight is superimposed on the drawing vehicle.

2.2.4     ‘Centre axle (simple) trailer’ means a towed vehicle (not being a full trailer or semi-trailer) equipped with a drawbar such that only a small static vertical load is transmitted to the drawing vehicle when uniformly loaded.

 

2.3     Brake terminology

2.3.1     ‘Air brake system’ means a system in which the brake requires the use of compressed air.

2.3.2     ‘Brake’ means the assembly in which the forces due to friction opposing the movement of the vehicle develop.

2.3.3     ‘Brake coupling’ (‘Coupling Head’) means the device for connecting the control and supply lines of the drawing vehicle to the control and supply lines of the trailer.

2.3.4     ‘Brake system’ means the combination of parts whose function is to progressively reduce the speed of a moving vehicle or bring it to a halt, or keep it stationary if it is already halted. The system consists of the control, the circuit and the foundation brake.

2.3.5     ‘Circuit’ means the combination of components between the control and the brake and linking them functionally. The circuit may be mechanical, hydraulic, pneumatic, electrical or mixed. Where the braking power is derived from or assisted by a source of energy independent of the driver but controlled by him, the reserve of energy in the device is likewise part of the circuit.

2.3.6     ‘Control’ means the part actuated directly by the driver to furnish to the circuit the energy required for braking or controlling it. This energy may be the muscular energy of the driver, or energy from another source controlled by the driver.

2.3.7     ‘Control (Service) line’ means the part of circuit along which the service brake signal is transmitted.

2.3.8     ‘Emergency braking’ - see 4.1.2

2.3.9     ‘Graduated braking’ means braking which, whether during application or release of the brakes, the driver can at any moment increase or decrease the braking force by acting on the control; and

If the control is actuated by the foot, or used for control of brake other than park brake the control must return to the ‘off’ position when released; and

2.3.10     ‘Load Sensing Device’ means a device fitted to the brake system to regulate the braking effort on any axle(s) in proportion to the load carried by the axle(s). (See section 4.1.4 and Annex A7).

2.3.11     ‘Parking braking’ - see 4.1.3

2.3.12     ‘Service braking’ - see 4. 1.1

2.3.13     ‘Supply (Emergency) line’ means the path by which any stored energy required to actuate the brakes is supplied.

2.3.14     ‘Spring brake’ means a brake in which the energy required for braking is supplied by one or more springs acting as an energy storage device.

2.3.15     ‘Trailer hand control’ means a hand operated control capable of applying a graduated service braking action on the towed trailer(s) only.

2.3.16     Threshold pressure. See Appendix A, A8.

 

3.0     Compliance

3.1     Initial compliance

Initial compliance with this code is the responsibility of the Certifier.

3.1.1     The Certifier shall provide the Statutory Authority on request with one copy of the statement of compliance for every vehicle type (with format as shown in Appendix C).

3.1.2     The Certifier shall supply, with every vehicle complying with this code, one copy of the statement of compliance (Appendix C). The operator of the vehicle shall be responsible for ensuring that the statement of compliance remains with the vehicle documentation, but not necessarily on the vehicle.

3.1.3     The Certifier will be responsible for the safe keeping of all the calculations, test reports and other documentation for each vehicle issued with a statement of compliance and also for making copies of such material available to the Statutory Authority on request. This material must include:

3.1.4     If a Certifier ceases his involvement with design certification to this code, the above mentioned records shall be forwarded to another practising Certifier and the Statutory Authority shall be notified of this change.

 

3.2     Continued compliance

Continued compliance with the code is a responsibility of the vehicle operator.

3.2.1     Servicing the brake system:

3.2.2     Modifications to the vehicle or the brake system:

 

4.0     Specifications

4.1     Requirements of the brake system

The brake system as defined in 2.3.4 must fulfil the following functions:

4.1.1     The service braking must make it possible to control the movement and retardation of the vehicle or vehicles in combination. It must be possible to graduate this braking action. The driver must be able to achieve this braking action from the driving seat without removing his hands from the steering control.

Service braking shall meet the requirements of Appendix A (Braking distribution) and should meet the requirements of Appendix B (Time response) of this code. Service braking must be capable of stopping the fully laden vehicle within 7 metres from 30 kilometres per hour (equivalent to an average deceleration of 5 m/s 2).

The service braking must act on all wheels of the vehicle.

4.1.2     The emergency braking must be capable of stopping the fully laden vehicle or vehicle combination within 18m from 30 km/hr (equivalent to an average deceleration of 2m/s 2) in the event of failure of the service braking. The driver must be able to achieve this braking action from the driving seat while keeping at least one hand on the steering control. For the purposes of these provisions it is assumed that not more than one failure of the service brake system will occur at one time.

4.1.3     The parking braking must be capable of holding the fully laden vehicle on an up or down gradient of 20% on a surface sealed to highway standard. The working parts must be held in the locked position by a purely mechanical device. From the driving seat, the driver must be able to achieve this braking action on the vehicle and any vehicle that it is designed to tow, subject, in the case of a trailer to the provisions of 4.4.2 below.

4.1.4     Wear on the brakes must be capable of being easily taken up by means of either a system of manual or automatic adjustment. In addition, the control and the components of the circuit and of the brakes must possess a reserve of travel such that, when the brakes become heated or the brake linings have reached a certain degree of wear, effective braking is ensured without immediate adjustment being necessary.

4.1.5     All components and devices in the brake system (including hoses and air connections) shall comply with at least one appropriate and recognised international, national or association standard where such standards exist. Recognised can be taken as meaning SAA, SAE, BS, JIS, ECE EEC, ISO, and DIN standards, in addition to other standards recognised by the statutory authority.

Friction materials shall comply with one of the following:

4.1.6     Vehicles fitted with load sensing devices shall only be used in combination with other vehicles also fitted with load sensing devices, however power driven vehicles and full trailers with a load sensing device fitted only to the rear axle set may be used in combination with vehicles without load sensing devices.

4.1.7     Vehicles to which anti-lock brake systems are fitted must comply with all the requirements of this code.

4.1.8     Traction control systems may utilise the brake system components provided the system is fail-safe and does not interfere with normal braking.

 

4.2     Air brake system

4.2.1     A pressure test connection complying with the dimensional requirements of Appendix D shall be fitted at the intake to the chamber of the least favourably placed brake chamber (or pneumatic device in the case of partly pneumatic brake systems) with respect to brake timing (Appendix B) on each independent circuit of the braking system. See also Appendix F, clause 3.0.

4.2.2     Spring brakes should be used for parking braking.

4.2.3     Compressed air braking systems incorporating load sensing devices or any valve which can be adjusted to modify the system pressure shall be fitted with pressure test connections in the pressure line upstream and downstream of the device.

4.2.4     Air connections between all drawing vehicles and trailers must be of the two line system, using a one piece coupling, e.g. a ‘duomatic’ coupling or when an auxiliary air supply - separate from the braking system - is required for a trailer, a ‘trimatic’ coupling.

4.2.5     All power driven vehicles first registered from 1 September 1991 shall be valved and piped to the rear cross-member, unless the manufacturer forbids the attachment of a trailer with a GVM of more than 3500 kg to a particular vehicle type.

4.2.6     The control (service) line shall be to the left side of the coupling and coloured blue or black, the supply (emergency) line shall be to the right side of the coupling and be coloured red or yellow, or identified, within 150 mm of coupling or junction.

4.2.7     The coupling block shall be situated close to the centre line, preferably to the right hand side of centre.

4.2.8     On drawing vehicle/semi-trailer combinations the hoses shall form part of the drawing vehicle or be detachable at both ends. On other combinations the hoses shall form part of the trailer and be securely attached to the drawbar. This requirement does not apply to combinations which are not uncoupled in the course of normal operation.

Caution: When fitting the female end to the front of a semi-trailer, only the trailer version without check valves shall be used.

4.2.9     Each reservoir in an air brake system shall be fitted with an automatic or manual condensate drain valve at the lowest point. Where an automatic condensate valve is fitted, the reservoir shall have provision for manual operation.

 

4.3     Power driven vehicles

4.3.1     The systems providing service, emergency and parking braking may have common components so long as they fulfil the following conditions:

4.3.2     Gauges shall be fitted to indicate to the driver the pressure in each independent service brake energy reserve (as defined in 4.3.1 (d)) and shall be visible to the driver in the normal driving position.

4.3.3     Where there are separate controls for the service brake system and the emergency brake system, simultaneous actuation of the two controls must not render both the service brake system and the emergency brake system inoperative, either when both brake systems are in good working order or when one of them is faulty.

4.3.4     Every vehicle equipped with a service brake actuated from an energy storage device (energy accumulator) must, where braking with the performance prescribed for emergency braking is impossible without the use of the stored energy, be equipped with an alarm device, in addition to any pressure gauge. The alarm device shall give an acoustical signal when the energy, in any part of the installation preceding the control valve, falls to a value which without refeeding the storage devices, guarantees that after four full-stroke actuations of the service brake control it is still possible on the fifth application to achieve the prescribed performance of the emergency brake (without failure in the service brake circuit). This alarm device must be directly and permanently connected to the circuit (See Clause 4.3.7(f))

This acoustical device may be rendered inoperative while the park-brake is applied and/or, at the choice of the manufacturer in the case of automatic transmission the selector is in the ‘Park’ position.

In verifying compliance with this clause, the vehicle’s brakes shall be correctly adjusted.

4.3.5     The auxiliary equipment must be supplied with energy in such a way that, even in the event of damage to the source of energy, its operation cannot cause the reserves of energy feeding the brake systems to fall below the level indicated in paragraph 4.3.4 above.

4.3.6     Retarders, other than exhaust brakes, shall not be capable of stalling the vehicle’s engine.

4.3.7     Power driven vehicles capable of towing a trailer of more than 3500 kg GVM shall meet the following requirements:

If the requirements of the specifications section of this code are achieved by compliance with ECE 13, then when the drawing vehicle’s emergency braking system comes into action, there must also be a graduated service braking action in the trailer.

 

4.4     Trailers

4.4.1     The brake systems must be such that the trailer is stopped automatically, in a progressive manner, if the supply line breaks while the trailer is in motion, or when the supply line pressure falls below 310 kPa.

4.4.2     Parking braking must be ensured when the trailer is separated from the drawing vehicle or when the supply line pressure falls below 310 kPa.

A person standing on the ground must be able to release the parking brake at least three times after the trailer has been uncoupled. In the case of air brake systems, the pressure in the supply line shall be between 650 and 665 kPa before uncoupling. These conditions must be satisfied when the brakes are adjusted to normal clearances.

The auxiliary park release device shall be such that the system is restored to normal automatically on the resumption of supply from the drawing vehicle.

4.4.3     The braking systems shall not compound their application forces.

4.4.4     As an alternative to the system capacity requirements of Appendix F, trailers with air brake systems shall have a minimum air reservoir capacity in litres equal to three times the maximum mass in tonnes carried by the trailer axles.

 

5.0     Exemptions for power driven vehicles which are equipped to tow trailers

5.1     Vehicles are exempt from clause 4.3.1(a) provided that the following requirements are met:

5.2     If the requirements of clause A3.4.1, A 3.4.2, A3.5.3 and A8.1 cannot be met, the manufacturer may apply to the Statutory Authority for an exemption.

 

Appendix A

Distribution of braking among the axles of vehicles and requirements for compatibility between drawing vehicle and trailer

A1.0     General

A1.1     This appendix relates to the retardation forces acting on the vehicle which are created by friction in the brakes; retardation forces which are applied through the drive axle do not form part of this appendix.

A1.2     The requirements of this appendix shall be met by vehicles when laden to the gross vehicle mass, EXCEPT in the case of vehicles fitted with load sensing devices, which must meet the requirements in all states of load. See Appendix E.

A1.3     A power driven vehicle not permitted to tow a trailer with a gross vehicle mass of more than 3500 kg is exempt from the requirements of this appendix provided that the vehicle is certified to an alternative standard that is acceptable to the statutory authority and:

A1.4     No device shall be fitted into the cab of the vehicle which would allow the driver to alter the vehicle’s braking with respect to the requirements of this appendix.

 

A2.0     Symbols

E = wheelbase

fi= Ti/Ni, adhesion utilised by axle i*

g = acceleration due to gravity

h = height of centre of gravity of the laden vehicle

ho = height of centre of gravity of drawing vehicle

hs = height of the transverse pivot axis of the coupling on which the semi-trailer rests

i = axle index (i = 1, front axle; i = 2, second axle; etc.).

J = deceleration of the vehicle

M = weight of vehicle

Mi = reaction normal to road surface on axle i under static conditions

MM = total normal static reaction between road surface and wheels of drawing vehicles for trailer or semi-trailer

MM = Mo + Mso

Mo = unladen mass of vehicle

Ms = Mso (1 + 0.45z) used only in paragraph 3.1, diagram 1, Adhesion Utilisation Criterion

Mso = difference between the maximum laden mass of the drawing vehicle and its unladen mass

Ni = vertical reaction of road surface on axle i under braking

pm = pressure at coupling head of control line

MR = total normal static reaction normal to road surface on all wheels on laden trailer or semi-trailer

T = force exerted by the brakes on axle i under normal braking conditions on the road

TM = sum of braking forces at the periphery of all wheels of drawing vehicles for trailers or semi-trailers

TR = sum of braking forces at periphery of all wheels of a trailer or semi trailer

z = braking ratio of vehicle = J/g*

* = Adhesion utilisation curves of a vehicle means curves showing for specified load conditions, and adhesion utilised by each axle i plotted against the braking ratio of the vehicle.

** = For semi-trailers, z is the braking force divided by the static weight on the semi-trailer axle(s).

 

A3.0     Requirements for power driven vehicles

A3.1     Two axle vehicles

A3.2     In the case of a power driven vehicle authorised to draw trailers fitted with compressed air brake systems, the pressure at full application of the braking control must be between 650 and 800kPa at the coupling head of the supply line and between 600 and 750kPa at the coupling of the control line, upon full service brake application, irrespective of the load condition of the vehicle. These pressures must be demonstrably present at the coupling of the drawing vehicle.

A3.3     Vehicles with more than two axles

In cases where the suspension geometry has a significant effect on the axle load distribution, the Certifier shall verify, by performing an on-road test with the vehicle loaded to GVM, that no wheels on the vehicle lock up at a deceleration of 4.5 m/s2.

A3.4     Vehicles other than drawing vehicles for semi-trailers

A3.5     Drawing vehicles for semi trailers

 

A4.0     Requirements for full trailers

A4.1     The requirements set out in Paragraphs A3.1 through to A3.4 inclusive shall apply to full trailers.

 

A5.0     Requirements for semi-trailers

A5.1     For vehicles with compressed air brakes the permissible relationship between the braking ratio TR/MM and the pressure (pm) shall lie within the shaded area shown in Diagram 2.

A5.2     The requirement of Paragraph A3.1(e) shall apply to vehicles with more than one axle if the suspension geometry affects the axle load distribution during braking (brake reactive suspensions).

A5.3     If the semi-trailer is itself a drawing vehicle for a second semi-trailer (i.e. the first semi-trailer in a B-Train), then the vehicle shall meet this requirement in the loaded condition specified in A3.5.

 

A6.0     Requirements for centre axle trailers

Centre axle trailers shall be subject to the requirements of A5.

 

A7.0     Load sensing devices

A7.1     In air brake systems load sensing devices should not modulate the pressure below 70 kPa.

A7.2     Vehicles fitted with load sensing devices must be fitted with a prominent sign stating that either the rear axle set or all axle sets are equipped with load sensing devices.

A7.3     Requirements to be met in the event of a failure of the control of the load sensing device:

 

A8.0     Threshold pressure tests for combination vehicles fitted with air brake systems

A8.1     The braking at the wheels shall commence at a pressure between 55 kPa and 80 kPa, measured at the coupling head of the control line. Braking shall be deemed to have commenced when a brake torque of 100 Nm is first reached at the wheel. For trailers equipped to tow a trailer, braking at all the wheels shall commence at a pressure between 50 kPa and 85 kPa, this pressure measurement shall be made at the coupling head of the control line of the drawing trailer. If there are very good and reasonable grounds to grant an exemption to this clause, then the approval of the statutory authority must be obtained.

 

Diagram 1

Adhesion utilisation criterion

(See Paragraph A3.1)

Adhesion utilisation by braking ratio.


Diagram 2

Drawing vehicles, semi-trailers and full trailers

(See Paragraphs A3.4, A4.1, A5.1) (See Diagram 3 for Tractors)

Drawing vehicles, semi-trailers and full trailers.

 

Diagram 3

Tractors for semi trailers

(See Paragraph A3.5. Also existing drawing vehicles and trailers first registered before 1 July 1991 which cannot be made to comply with Diagram 2)

Tractors for semi trailers.

 

Appendix B

Requirements for measuring the response time on vehicles equipped with compressed air brakes

B1.0     General

B1.1     The response times of the brake system shall be determined on the stationary vehicle, the pressure being measured at the intake to the cylinder of the least favourably placed brake and at the coupling head if present.

During the test the free stroke in the brake cylinders of the various axles shall be as specified by the Certifier.

The response times determined in accordance with the provisions of this Appendix shall be rounded to the nearest tenth of a second. If the figure representing the hundredth is five or more, the response time shall be rounded up to the next higher tenth.

 

B2.0     Power driven vehicles

B2.1     At the beginning of each test the pressure in the energy storage device shall be equal to the pressure at which the governor restores the feed to the system. In systems not equipped with a governor (e.g. limited maximum compressors) the pressure in the energy storage device at a beginning of each test shall be 90% of the pressure specified by the certifier.

B2.2     The time elapsing from the initiation of a full brake-pedal actuation to the moment when the pressure in the brake cylinder reaches 75% of its final value shall not exceed 0.6 seconds.
The time elapsing from the release of the fully depressed brake pedal to the moment when the brake pressure reaches 25% of its initial value shall not exceed 0.6 seconds.

B2.3     In the case of vehicles having a brake coupling for trailers the response time must be measured at the coupling head. During this test a volume of 385 + 5cm3 (which is deemed to be the equivalent to the volume of a pipe 2.5m long with an internal diameter of 13mm and under a pressure of 650 kPa) shall also be connected to the coupling head of the control and supply lines. Tractive units for semi-trailers must be equipped with flexible pipes for making the connection to semi-trailers. The coupling heads will therefore be at the extremity of those flexible pipes.

The time elapsing from the initiation of a full brake pedal actuation to the moment when the pressure measured at the coupling head of the control line reaches 75% of its final value shall not exceed 0.4 seconds.

The time elapsing from the release of the fully depressed brake pedal to the moment when the coupling head pressure reaches 25% of its initial value shall not exceed 0.6 seconds.

 

B3.0     Trailers, including semi-trailers

B3.1     The trailers response time shall be measured without the drawing vehicle. To replace the drawing vehicle it is necessary to provide a simulator to which the trailer’s control line and supply line coupling heads are connected.

B3.2     The pressure in the supply line shall be:

650 kPa +15 -0

B3.3     The simulator shall have the following characteristics:

B3.4     The time elapsing between the moment when the pressure produced in the control line by the simulator reaches 65 kPa and the moment when the pressure in the brake actuator of the trailer reaches 75% of the asymptotic value must not exceed 0.4 seconds.

When releasing pressure the time elapsing between the moment when the pressure produced in the control line by the simulator reaches 490 kPa to the moment when pressure in the brake actuator of the trailer reaches 25% of its initial value shall not exceed 0.6 seconds.

B3.5     Semi-trailers laid out for towing a second (semi) trailer shall meet the following requirements:

 

B4.0     Partly pneumatic brake systems

B4.1     For partly pneumatic brake systems the requirements of paragraphs B1, B2 and B3 pertaining to the coupling head shall be met. The requirements in paragraphs B1, B2 and B3, cornering the least favourably placed chamber shall apply to the least favourably placed pneumatic device which acts on the non-pneumatic part of the brake system.

Diagram 1 applies to Test Equipment A Supply connection with shut off valve.

C1 = Pressure switch in the simulator, set at 65 kPa and at 490 kPa.

C2 = Pressure switch to be connected to the brake actuator of the trailer, to operate at 75% of the asymptotic pressure in the brake actuator CF.

CF = Brake cylinder.

L = Line from orifice 0 up to and including its coupling head TC, having an inner volume of 385 ± 5cm3 under a pressure of 650 kPA.

M = Pressure gauge.

0 = Orifice with a diameter of not less than 4mm and not more than 4.3mm.

PP= Pressure test connection.

R1 = 30 litre air reservoir with drain valve.

R2 = Calibrating reservoir, including its coupling head TC, to be 385 ± 5cm3.

R3 = Calibrating reservoir, including its coupling head TC, to be 1155 ± 15cm3.

RA = Shut off valve.

TA = Coupling head, supply line.

TC = Coupling head, control line.

V = Braking control device.

VRU= Relay valve

 

1. Setting the Simulator

Diagram for setting the simulator.

 

2. Testing the trailer

Diagram for testing the trailer.

 

Appendix C

Statement of compliance with the New Zealand Heavy Vehicle Brake Code

VEHICLE TYPE:          
MAKE:   MODEL:  
SERIAL NO.:      
GVM:   GCM:  
UNLADEN CoG HEIGHT:   WHEELBASE:  
UNLADEN MASS, FRONT:   UNLADEN MASS REAR:  
PAYLOAD:   POSITION: RANGE:
PAYLOAD CoG HEIGHT:   POSITION: RANGE:
FIFTH WHEEL HEIGHT*:      
FRONT SUSPENSION TYPE:   REAR SUSPENSION TYPE:  
REACTIVE/NONREACTIVE:   REACTIVE/NONREACTIVE:  
SYSTEM PRESSURE:   MAXIMUM OPERATING Pm………..kPa  
    GOVERNOR CUTIN Pg………...kPa  
    TIME Pg to Pm……….. secs  

 

Axle   Coupling
Threshold
kPa @
1OONm
Brake Force
kN/kPa @
Brake Pot
Tyre Size   Friction Material
Make Id No. CoF

1

 

 

 

 

 

 

2

 

 

 

 

 

 

3

 

 

 

 

 

 

4

 

 

 

 

 

 

 

Axle Brake Type Drum
Diameter
Chamber Size Slack Length Spring Force

1

 

 

 

 

 

2

 

 

 

 

 

3

 

 

 

 

 

4

 

 

 

 

 

 

* Horizontal distance from front axle set

* See Fifth Wheel Standard NZS5450 (1989)

* Park brake spring force

1.1

TRUCK OR TRACTOR
VALVE TYPE MAKE MODEL VERSION
Treadle      
Primary Circuit Relay      
Sec. Circuit Relay      
Trailer Control Relay      
Load Sensing      
Synchronising      
Quick Release      
Park Brake      
Trailer Hand Control      
TRAILER
Relay 1      
Relay 2      
Spring Brake      
Quick Release Valve      
Pilot I      

A copy of the calculations, test reports, and other documentation which demonstrates that this vehicle complies with the New Zealand Heavy Vehicle Brake Code must be made available to the statutory authority on request.

I, the undersigned do hereby certify that the vehicle identified above complies with all requirements of the current New Zealand Heavy Brake Code.

Date: ___________________________ Signed: _________________________

Certifier’s Identification:

Name: __________________________ Phone: _________________________

Postal address: ____________________ Fax: ___________________________

______________________________________________________________

Position ________________________________________________________

Modification

I, the undersigned, do hereby re‑certify the vehicle identified above, as modified complies with all requirements of the current New Zealand Heavy Brake Code.

Date: ___________________________ Signed: _________________________

Certifier’s Identification:

Name: __________________________ Phone: _________________________

Postal address: ____________________ Fax: ___________________________

______________________________________________________________

Position ________________________________________________________

 

Appendix D

Pressure test connections for compressed air braking systems

Dimensions of the typical connection.

Drawing showing the dimensions of the typical connection.

 

valve position dimension ‘a’
closed 5 mm
open 3 mm

Dimensions not specified are to be chosen according to the application.

Seals and covers shall withstand petroleum products.

 

Free space to be reserved around the pressure test connection

Dimensions in millimetres

Free space to be observed around the pressure test connection.

 

Appendix E

Maximum vehicle and axle weights. (Feb. 1989)

Wheels
1/2 axle limit plus 500 kg.
Single standard tyred axle
Single standard tyred axle (tyres at least 330 mm (13 ins) width by 24 ins. diameter or 355 mm (14 ins.) width by 19.5 ins. diameter)
Twin tyred axle
  Note: For weights on oscillating axles and other axle combinations not shown above, refer to the Heavy Motor Vehicle Regulations 1974. Amendment No. 5.

Wheel-weight chart.

,000kgDistance from first to last axle of any axle group of the vehicle or combination
1.8m but less than 2.5m 15,500kg
2.5m but less than 3.0m 17,500kg
3.0m but less than 3.3m 19,000kg
3.3m but less than 3.6m 20,000kg
3.6m but less than 4.0m     21,000kg
4.0m but less than 4.4m     22,000kg
4.4m but less than 4.7m     23,000kg
4.7m but less than 5.1m 24,000kg
5.1m but less than 5.4m 25,000kg
5.4m but less than 5.8m 26,000kg
5.8m but less than 6.4m 27,000kg
6.4m but less than 7.0m 28,000kg
7.0m but less than 7.6m 29,000kg
7.6m but less than 8.2m 30,000kg
8.2m but less than 8.8m 31,000kg
8.8m but less than 9.4m 32,000kg
9.4m but less than 10.0m 33,000kg
10.0m but less than 10.8m 34,000kg
10.8m but less than 11.6m 35,000kg
11.6m but less than 12.4m 36,000kg
12.4m but less than 13.2m 37,000kg
13.2m but less than 13.5m 38,000kg
13.5m but less than 14.4m 39,000kg
14.4m but less than 14.8m 40,000kg
14.8m but less than 15.2m 41,000kg
15.2m but less than 15.6m 42,000kg
15.6m but less than 16.0m 43,000kg
16.0m and over 44,000kg

 

Appendix F

(Reprinted from ECE 13, Annex 7)

Provisions relating to energy sources and energy storage devices ('energy accumulators')

Compressed-air devices braking systems

1.0     Capacity of storage devices ('Energy Accumulators')

1.1     General

1.1.1     Vehicles on which the braking device requires the use of compressed air shall be equipped with energy storage devices (‘energy accumulators’) of a capacity meeting the requirements of Paragraph 1.2 and 1.3 below.

1.1.2     However the energy storage devices shall not be required to be of a prescribed capacity if the braking system is such that in the absence of any energy reserve it is possible to achieve a braking performance at least equal to that prescribed for the emergency braking system.

1.1.3     In verifying compliance with the requirements of Paragraphs 1.2 and 1.3 below, the brakes shall be adjusted as closely as possible.

 

1.2     Power-driven vehicles

1.2.1     The air brake reservoirs of power-driven vehicles shall be so designed that after eight full-stroke actuations of the service brake control the pressure remaining in the air brake reservoir shall be not less than the pressure required to obtain the specified secondary (emergency) braking performance.

1.2.2     Testing shall be performed in conformity with the following requirements.

 

1.3     Trailers and semi-trailers

1.3.1     The energy storage devices ('energy accumulators') with which trailers and semi-trailers are equipped shall be such that after eight full-stroke actuations of the drawing vehicle’s service braking device the energy level supplied to the operating members using the energy does not fall below a level equivalent to one-half of the figure obtained at the first brake application.

1.3.2     Testing shall be performed in conformity with the following requirements:

 

2.0     Capacity of energy sources

2.1     General

The compressors shall meet the requirements set forth in the following paragraphs.

 

2.2     Definitions

2.2.1     ‘p1’ is the pressure corresponding to 65% of the pressure p2 defined in Paragraph 2.2.2 below.

2.2.2     ‘p2 ’ is the value specified by the manufacturer and referred to in Paragraph 2.2.1 above.

2.2.3     ‘T1’ is the time required for the relative pressure to rise from 0 to p1 , and T2 is the time required for the relative pressure to rise from 0 to p2.

 

2.3     Conditions of measurement

2.3.1     In all cases of r.p.m. speed of the compressor shall be that obtained when the engine is running at the speed corresponding to its maximum power or at the speed allowed by the governor.

2.3.2     During the tests to determine the time T1, and the time T2 the auxiliary servo energy storage device or devices shall be isolated.

2.3.3     If it is intended to attach a trailer to a power driven vehicle, the trailer shall be represented by an energy storage device whose maximum relative pressure p (expressed in bars) is that which can be supplied through the drawing vehicle’s feed given by the formula p.V = 20R (R being the permissible maximum load, in tonnes, on the axles of the trailer or semi-trailer).

 

2.4     Interpretation of results

2.4.1     The time T1 recorded for the least favoured energy storage devices shall not exceed:

2.4.2     The time T2 recorded for the least favoured energy storage device shall not exceed:

 

2.5     Additional test

2.5.1     If the power driven vehicle is equipped with one or more auxiliary servo energy storage devices having a total capacity exceeding 20% of the total capacity of the braking energy storage devices an additional test shall be performed during which no irregularity shall occur in the operation of the valves controlling the filling of the auxiliary servo energy storage device or devices.

2.5.2     It shall be verified during the aforesaid test that the time T3 necessary to raise the pressure from 0 to P2 in the least favoured braking energy storage device is less than:

2.6     The test shall be performed in the conditions prescribed in Paragraphs 2.3.1 and 2.3.3.

 

3.0     Pressure connections

3.1     To facilitate the periodic inspection of vehicles already in use on the road, a pressure connection shall be fitted close to the least favourably placed storage device.

3.2     The pressure connection shall comply with Appendix 2 to Annex 6 to this Regulation containing the drawings according to ISO 3583- 1975.

 

Land Transport Rule - Heavy-vehicle Brakes - Rule 32015
Land Transport Safety Authority of New Zealand, Te Mana Marutau Waka Whenua o Aotearoa