Vital outcomes so far tools to identify curving and rolling noise sources and allow prescription of reliable mitigation methods and to manage them. A standard process to select mitigation strategies based on costs and benefits

Motivation for Research – Rail noise issue now recognised – Noise barriers are a “blunt instrument” – Some aspects are relatively simple to address by: changing operational procedures: yard noise; horns; idling standard industrial noise control : locomotives, traction equipment Vibration isolation: vibration reducing track – but other aspects not simple, requiring research: Curve noise Noise source identification tools to communicate cost / benefit of noise control

Major Tools Now Available 1.Curving noise a.Mechanism identification: On-board and Trackside located. b.Standard definitions. c.Key mechanisms consolidated leading to effective mitigation. d.Mitigation method evaluation. 2.Rolling noise a.Noise prediction software (RRNPS) is now available, calibrated to Australian situations. b.Noise separation algorithm to direct mitigation method selection and management. c.A scientific method for evaluating potential mitigation strategies is now available. 3.Cost / benefit analysis a.A standardised approach to benefit and cost identification. b.A step by step guide to noise mitigation and management. c.Advice on the effectiveness of potential noise mitigation methods.

General Process

Curve Noise Mechanisms Conventional theory Curve squeal – Lateral sliding between the Inner wheel tread and rail head Flanging noise – HIGH rail flange contact New understanding Curve squeal – Flange contact on both rails – Wheel tread on top of both rails Flanging noise – HIGH and LOW rail flange contact 8

Curve Noise Mitigations (1) 9

Curve Noise Source Identification (2) 10

 connection between bolster and carbody  connection between bolster and sideframe  connection between sideframe and axlebox Vehicle Dynamics Modelling

AOA of the Leading Axles by varying centre bowl friction and warp stiffness

1.The major influencing factors increasing AOA are, in sequence: the centre bowl friction the warp stiffness the friction coefficient of sidebearers and the preload of sidebearers Rail gauge corner lubrication makes the leading wheelset AOA becomes larger 2.The worst combination of bogie parameters in regards to AOA is high centre bowl friction level combined with low warp stiffness due to wedge rise. 17th July 2012 Summary

RRNPS Rolling Noise Prediction

Noise and Roughness Separation- Set Up Ballast Sleeper Rail Pad A1 A2 A3 A4 A5 R1, 2 O1, 2 Stick 7.5m A1, 2 R1 R2 A3, 4 A5 O1 O2 M1 M2

Field Trial - Noise Separation Method

Field Trial – Roughness Separation Method

Economics of Noise Mitigation Strategies Figure 1: Major "Players" and Transactions that Affect Rail Management

What it means for you NOW we have the tools to identify curving and rolling noise sources CAN use the tools to allow prescription of reliable mitigation methods and to manage them. HAVE a standard process to predict or diagnose noise sources and select mitigation strategies based on costs and benefits

Who to Contact? Richard Dwight: