Directive Train Horn Demonstration System Performance

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Directive Train Horn Demonstration System
Performance
Paul Burgé, INCE BD.CERT, URS Corporation Parke
Rhoads, Acentech Incorporated
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• The Train Horn Problem
• Train horn noise is typically the loudest and
  most annoying component of train noise in areas
  near grade crossings
• Train horn soundings are generally required at
  most highway/rail grade crossings
• Most train horns are generally omni directional,
  casting acoustical energy in all directions
  without regard to where the signal is needed or
  unwanted.

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• Train Horn Directionality

Source Raposa and Fleming, IWRN 2001
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• Train Horn Noise Solutions
• More grade separations
• Quad gate crossings
• Median barriers
• One way streets
• Wayside horns
• Directional train horns

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• Directional Train Horn Concept

Source Coate, Kern and Africk, IWRN 2001
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• Directional Train Horn Benefits

• Fleet horn upgrades would provide noise reduction
  benefit at all grade crossings where horns are
  currently sounded
• No ambiguity or habituation (relative to wayside
  horn)
• Would work for virtually all grade crossing
  configurations
• Retains traditional train horn warning signal
  information with regard to trains relative
  proximity and direction
• Could be implemented in a cost efficient manner
• Looks cool

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• Acoustic Line Array

Summation(constructive interference)
Cancellation(destructive interference)
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• Direction Train Horn Demonstration Opportunity

Contractors URS and Acentech were asked by The
Los Angeles County Metropolitan Transit Authority
(MTA) to develop a unit to demonstrate whether a
directive horn could successfully reduce crossing
noise levels noise levels on recently opened MTA
Gold Line light rail transit line under an
existing contract
Typical MTA Gold Line grade crossing
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Demonstration System Project Approach

• Evaluate existing warning system
• Design system for improved directivity
• Static laboratory tests and refinement
• Limited static and dynamic field test and
  refinement (road vehicle)
• Full static and dynamic field test and evaluation
  (rail vehicle)

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• MTA Gold Line LRT Vehicle

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Proposed train mounted array horn (artists
conception)
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Directional array demo system and block diagram
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Truck mounted horn array
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Directivity Test setup
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Measured Warning System Directivity
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Dynamic pass-by test setup
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Dynamic pass-by test setup
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Community Noise Analysis
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Future Design Refinements

• Varying Number or Directivity of Array Elements
• Curved Array Geometry
• Non-uniform Array Element Spacing
• Electronic Delay and Phasing
• Higher-order Gradient Array Configuration

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Optimal Warning System Directivity
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Questions or Comments