TRB ADC 40 Noise and Vibration 2006 Summer

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Directive Train Horn Demonstration System Performance Paul Burgé, INCE BD. CERT, URS Corporation Parke Rhoads, Acentech Incorporated 10/7/2020 Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting 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. Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Train Horn Directionality Source: Raposa and Fleming, IWRN 2001 Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Train Horn Noise Solutions: § § § More grade separations Quad gate crossings Median barriers One way streets Wayside horns Directional train horns Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Directional Train Horn Concept: Source: Coate, Kern and Africk, IWRN 2001 Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting 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 train’s relative proximity and direction • Could be implemented in a cost efficient manner • Looks “cool” Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Acoustic Line Array: – Cancellation (destructive interference) Summation (constructive interference) Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting 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 on recently opened MTA Gold Line light rail transit line under an existing contract Typical MTA Gold Line grade crossing Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting 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) Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting MTA Gold Line LRT Vehicle Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Proposed train mounted array horn (artist’s conception) Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Directional array demo system and block diagram Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Truck mounted horn array Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Directivity Test setup Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Measured Warning System Directivity Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Dynamic pass-by test setup Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Dynamic pass-by test setup Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Community Noise Analysis Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting 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 Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Optimal Warning System Directivity Acoustics and Noise and Control Services

TRB ADC 40 Noise and Vibration 2006 Summer Meeting Questions or Comments Acoustics and Noise and Control Services