WORLD-FIRST STANDARD FOR ENGINE
BRAKE NOISE
International Heavy Vehicle Symposium
Neil Wong
Senior Manager Environment
16 March 2010
About the National Transport Commission
 Mission: we lead transport reform nationally to meet the
end to end supply chain needs of transport users and the
broader community for safe, efficient and sustainable
land transport
 Report to the Australian Transport Council
Overview
 Background
 Development of the standard
 Introducing the standard
Background
 What are engine brakes?
 Why are they a problem?
 ATC directed NTC to examine the problem
What are engine brakes?
 Secondary retarders
 Assists heavy vehicles to slow down without use of
service brakes
– exhaust brakes
– hydraulic retarders
– electromagnetic retarders
– regenerative brakes (future)
– engine brakes
Why are they a problem?
 Excessive engine brake noise is a major source of
complaint from the community
ATC directed NTC to address the problem
 All engine brakes are reasonably quiet when new
because the mufflers are well designed in in good
condition
 Engine brakes will become noisy when mufflers
deteriorate or are replaced with an inferior produced
muffler
 Solution involves trucks fitting decent mufflers
Development of the standard
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National Transport Commission
Department of Transport, Energy and Infrastructure SA
NSW Roads and Traffic Authority
VicRoads
Industry
Truck manufacturers
Development of the standard
 Propose using modulation:
– Test program run in 2002 and 2003
– Engine Brake Noise: Development of a Roadside Test
Procedure report released in September 2003
 Threshold level of annoyance using modulation:
– Engage experts to refine modulation
– Further test program
– Run a series of panels using community participants
– Draft proposal released in June 2006
 Finalise standard
– Refine proposal from public feedback
– ATC approves in November 2007
– Root mean squared of 3
Video
Introducing the standard
 NSW and Victoria are introducing laws and will enforce
the standard
 Enforcement includes noise cameras