REPORT NO. FRA/ORD-80/91 PB ^ 1 ,<c/ 3 ^ - * «• - ASSESSMENT OF UXQMDTIVE CREW IN-CAB OCCUPATIONAL NOISE EXPOSURE Roger D. K ilmer National Bureau of Standards National Engineering Laboratory Washington ^ DC 20234 DECEMBER 1980 FINAL REPORT Document is available to the public through the National Technical Information Service, Springfield, Virginia 22161. Prepared for U.S. DEPARTMENT OF TRANSPORTATION FEDERAL RAILROAD ADMINISTRATION Office of Research end Development Washington, D.C. 20590 04-Locomotives/Propulsion * \ 1 NOTICE This document is disseminated under the sponsorship of the Depart­ ment of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. NOTICE The United States Government does not endorse products or manufac­ turers. Trade or manufacturers' names appear herein solely because they are considered essential to the object of this report. Vv Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Cotalug No. FRA/ORD-80/91 4. Title and Subtitle 5. Report Date ASSESSMENT OF LOCOMOTIVE CREW IN-CAB December 1980 OCCUPATIONAL NOISE EXPOSURE 6. Performing Organization Code 8. Performing Organization Report No. 7. Au thor^ s) Roger D. Kilmer 9. Performing Organization Name ond Address 10. Work Unit No. (TRAIS) National Bureau of Standards National Engineering Laboratory 11. Contract or Grant No. Washington, DC 20234 13. Type of Report and Period Covered 12. Sponsoring Agency Name ond Address U.S. Department of Transportation Federal Railroad Administration Final Report Office of Rail Safety Research 14. Sponsoring Agency Code Washington, DC 20590 15. Supplementary Notes 16. Abstract The railroad industry, unlike m o s t other'U.S. industries, is not subject to the safety regulations of the Occupational Safety and Health Administration. Instead, railroad workers are covered by the safety regulations of the Federal Railroad Administration (FRA). This report documents an extensive study designed to assess the noise environment in locomotive cabs. Operational duty cycle and in-cab sound level data are presented for 18 test runs made on 16 different locomotives used in wide range of operational modes (e.g., through freight and local transfer freights), varied terrains (mountainous, undulating and flat) and varied trip lengths (6 to 12 hours). The general conclusion of this study is that there does not appear to be a widespread problem of overexposure to noise based on the same type of evaluation as currently used by OSFA (only 1 out of 18 test runs exceeded the criteria). The noise exposure is within acceptable limits because the operational duty cycle is such that the sources which generate high sound levels (horn and brake) are operating only for short periods of time and because the locomotive spends a great deal of time in idle (diesel engine sound levels below 90 dB). However, there was one test run for which an overexposure to noise was measured. To pinpoint such cases where overexposure to noise may occur, a simplified testing procedure is developed. This test consists of making in-cab sound level measurements of engine notch 8 (no load), horn sounding and brake application with the locomotive stationary. With these three sound level measurements and an estimate of the time that the locomotive is operating on-line, the in-service noise dose can be estimated and a pass/fail assessment made of whether the noise exposure might exceed acceptable limits. 17. Key Words 18. Distribution Statement locomotive crew Document is available to the U. S. public simplified testing through the National Technical Information in-cab sound level Service, Springfield, Virginia 22161 19. Security Clattif. (of this report) 20. Security Clossif. (of this poge) 21* No. of Pages 22. Price Form DOT F 1700.7 (8—72) Reproduction of completed page authorized 1 c _? * i * METRIC CONVERSION FACTORS 9 23 Approximate Conversions to Metric Measures Approxim ate Conversions from Metric Measures 22 Symbol When You Know Multiply by To Find S y m b o l Symbol When You Know Multiply by To Find Symbol -21 8 LENGTH 20 LENGTH = ---------- --------- 19 m m millimeters 0 .0 4 inches in = cm centimeters 0 .4 inches in = m meters 3.3 feet ft in inches ‘ 2 .5 centimeters cm ---------18 m meters 1.1 yards yd n feet 30 centimeters cm = = k m kilom eters 0.6 miles m i y d yards 0 .9 meters m 17 mi miles 1.6 kilom eters km = ---------16 AREA AREA 6 cm 2 square centimeters 0 .1 6 square inches in2 15 in2 square inches 6 .5 square centimeters cm 2 = m 2 square meters 1.2 square yards y d 2 ft2 square feet 0 .0 9 square meters m 2 = k m 2 square kilometers 0 .4 square miles m i2 ----------14 y d 2 square yards 0 .8 square meters m 2 ha hectares (10,000 m2 ) 2.5 acres m i2 square miles 2 .6 square kilometers k m 2 acres 0 .4 = 13 hectares ha 5 M ASS (weight) MASS (weight) = = g grams 0 .0 3 5 ounces OZ oz ounces 28 grams — <------ 9 — 11 kg kilogram s 2 .2 pounds lb lb pounds 0 .4 5 kilogram s kg = --------- t tonnes (1000 kg) 1.1 short tons short tons 0 .9 tonnes t 4 (2 0 0 0 lb) — 10 = VOLUME VOLUME g == milliliters fl oz tsp teaspoons 5 milliliters m l 9 ml 0 .0 3 fluid ounces ~ i liters 2.1 pints Pt T b s p tablespoons 15 milliliters m l 3 = fl oz fluid ounces 30 milliliters m l i liters 1.06 quarts q t — ------------7 gal c cups 0 .2 4 liters i I liters 0 .2 6 gallons = pt pints 0 .4 7 liters i m* cubic meters 3 6 cu b ic feet ft* q t quarts 0 .9 5 liters i ------- —6 m 3 cubic meters 1.3 cubic yards yd* gal gallons 3.8 liters i ft* cu b ic feet 0 .0 3 cubic meters m 3 2 ------------5 TEM PERATURE (exact) yd* cubic yards 0 .7 6 cubic meters m* 4 TEM PERATURE (exact) ° C Celsius 9/5 (then Fahrenheit ° F temperature add 32) temperature 3 ° F Fahrenheit 5/9 (after Celsius ° C temperature subtracting temperature 1 ° F 3 2 ) ° F 32 9 8 .6 212 4 0 0 4 0 8 0 120 160 2001 1 l 1 l 1 i 1 l 1 | 1 1 1 1 ll ll 1 il II 11 *1 In. - 2.64 cm (exactly). For other exact conversions and more detail tables Me i 1 r i i — 1 r 1 T “ 1 1 NBS Mite. Publ. 286. Units of Weight and Measures. Price $2.26 SO Catalog 4 0 - 2 0 20 40 60 80 100 No. C13 10 286. Inches — °C 37 ° C > TABLE OF CONTENTS Page List of Figures............. v List of T a b l e s .................... vil Conversion Table to SI U n i t s .................................. xi Executive Summary ............................................. xiii 1.0 Introduction...................... 1 2.0 Occupational Noise Exposure .............................. 3 3.0 Existing Locomotive Data ...................... ...... 13 3.1 In-Cab N o i s e ....................................... 13 3.2 Operational Duty C y c l e .............................. 1*3 3.2.1 Diesel Engine Operations . ..................... 20 3.2.2 Brake Applications ............................ 25 3.2.3 Horn Soundings................................ 30 3.3 Fleet Population .................................... 33 4.0 Field Test. Program....................................... 39 4.1 Instrumentation System .............................. 40 4.2 Test Procedures...................................... 48 5.0 Test Results and Conclusions.............................. 51 5.1 Operational Duty C y c l e .............................. 31 5.2 In-Cab Noise Levels .................................. 60 5.2.1 Spatial Variation in the C a b ................... 67 5.2.2 Effect of Locomotive Operations ............... 72 5.2.3 Effect of Terrain Features ..................... 85 5.3 Crew Noise Exposure.................................. 39 5.3.1 Spatial Variation in the Cab . ........... 91 5.3.2 Crew Noise Exposure for the Overall T r i p ........ 9L 5.3.3 Crew Noise Exposure for Alternative Criteria . 98 5.3.4 Comparison of the Crew Noise Exposures for the Fixed and Lapel Microphones ............... 103 5.3.5 Effect of the Locomotive Operations ........... 106 5.3.6 Effect of Terrain Features ..................... 109 i ii Page 5.4 Summary and Conclusions.................................112 6.0 Stationary Screening T e s t ................................ 116 6.1 Ideal Relationship .................................. 116 6.2 Existing Procedures .................................. 119 6.3 Development of the Stationary Screening T e s t ............122 6.4 Stationary Screening Test Procedure .................... 140 6.5 Determining the Principal Noise Source ................ 147 6.6 Conclusions and Recommendations ...................... 149 7.0 Appendix A. Descriptions of Locomotive Characteristics and Train Parameters...............................151 8.0 References..................................................164 9.0 Acknowledgements .......................................... 168 IV LIST OF FIGURES Page Figure 1. Time/intensity relationship for the current OSHA standard [2] ...................................... 4 Figure 2. Comparison of the time/intensity relationships for the current OSHA standard [2], the proposed NIOSH criteria [9], and the equal-energy criteria [10] . 9 F igure 3. Approximate relationship between sound level and expo­ sure time for various types of locomotive operations 11 Figure 4. Sound level versus frequency for conditions of engine only (notch 8) and engine (notch 8) with horn in use for an EMD SD45 locomotive [12] ....................... 19 Figure 5. Schematic diagram of instrumentation system developed by NBS for evaluation of the noise exposure of loco­ motive crews ...................................... 41 F igure 6. View inside the cab of one of the test locomotives showing the locations of the three microphones near the engineer....................................... 43 F igure 7. Operational keyboard used to record locomotive operations and terrain changes ..................... 45 Figure 8. Examples of the relationships of various noise ratings to different sound level time histories ............