Title: Directive Train Horn Demonstration System Performance
1Directive Train Horn Demonstration System
Performance
Paul Burgé, INCE BD.CERT, URS Corporation Parke
Rhoads, Acentech Incorporated
2- 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. -
3- Train Horn Directionality
Source Raposa and Fleming, IWRN 2001
4- Train Horn Noise Solutions
- More grade separations
- Quad gate crossings
- Median barriers
- One way streets
- Wayside horns
- Directional train horns
-
5- Directional Train Horn Concept
-
Source Coate, Kern and Africk, IWRN 2001
6- 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
7Summation(constructive interference)
Cancellation(destructive interference)
8- 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
9Demonstration 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)
10- MTA Gold Line LRT Vehicle
11Proposed train mounted array horn (artists
conception)
12Directional array demo system and block diagram
13Truck mounted horn array
14Directivity Test setup
15Measured Warning System Directivity
16Dynamic pass-by test setup
17Dynamic pass-by test setup
18Community Noise Analysis
19Future 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
20Optimal Warning System Directivity
21Questions or Comments