[Code of Federal Regulations]

[Title 40, Volume 24]

[Revised as of July 1, 2006]

From the U.S. Government Printing Office via GPO Access

[CITE: 40CFR201.26]



[Page 79-80]

 

                   TITLE 40--PROTECTION OF ENVIRONMENT

 

         CHAPTER I--ENVIRONMENTAL PROTECTION AGENCY (CONTINUED)

 

PART 201_NOISE EMISSION STANDARDS FOR TRANSPORTATION EQUIPMENT; INTERSTATE 

RAIL CARRIERS--Table of Contents

 

                     Subpart C_Measurement Criteria

 

Sec.  201.26  Procedures for the measurement on receiving property of 

retarder and car coupling noise.



    (a) Retarders--(1) Microphone. The microphone must be located on the 

receiving property and positioned at a height between 1.2 and 1.5 meters 

(4 to 5 feet) above the ground. The microphone must be positioned with 

respect to the equipment in accordance with the manufacturers' 

recommendations for Type 1 or 2 performance as appropriate. No person 

may stand between the microphone and the equipment being measured or be 

otherwise positioned relative to the microphone at variance with the 

manufacturers' recommendations for Type 1 or 2 performance as 

appropriate.

    (2) Data. The maximum A-weighted sound levels (FAST) for every 

retarder sound observed during the measurement period must be read from 

the indicator and recorded. At least 30 consecutive retarder sounds must 

be measured. The measurement period must be at least 60 minutes and not 

more than 240 minutes.

    (3) Adjusted average maximum A-weighted sound level. The energy 

average level for the measured retarder sounds must be calculated to 

determine the value of the average maximum A-weighted sound level 

(Lave max). This value is then adjusted by adding the 

adjustment (C) from Table 2 appropriate to the number of measurements 

divided by the duration of the measurement period (n/T), to obtain the 

adjusted average maximum A-weighted sound level 

(Ladj ave max) for retarders.

    (b) Car coupling impact--(1) Microphone. The microphone must be 

located on the receiving property and at a distance of at least 30 

meters (100 feet) from the centerline of the nearest track on which car 

coupling occurs and its sound is measured (that is, either the 

microphone is located 30 meters (100 feet) from the nearest track on 

which couplings occur, or all sounds resulting from car coupling impacts 

that occur on tracks with centerlines located less than 30 meters (100 

feet) from the microphone are disregarded). The microphone shall be 

positioned at a height between 1.2 and 1.5 meters (4 and 5 feet) above 

the ground, and it must be positioned with respect to the equipment in 

accordance with the manufacturers' recommendations for Type 1 or 2 

performance as appropriate. No person may stand between the microphone 

and the equipment being measured or be otherwise positioned relative to 

the microphone at variance with the manufacturers' recommendations for 

Type 1 or 2 performance as appropriate.

    (2) Data. The maximum A-weighted sound levels (FAST) for every car 

coupling impact sound observed during the measurement period must be 

read from the indicator and recorded. At least 30 consecutive car 

coupling impact sounds must be measured. The measurement period must be 

at least 60 minutes and not more than 240 minutes, and must be reported.



[[Page 80]]







Table 2--Adjustment to Lave max To Obtain Ladj ave max for Retarders and

                        Car Coupling Impacts \1\

 [n/T=number of measurements/measurement duration (min) C=Adjustment in

                                   dB]

0.111 to 0.141..................................................      -9

0.142 to 0.178..................................................      -8

0.179 to 0.224..................................................      -7

0.225 to 0.282..................................................      -6

0.283 to 0.355..................................................      -5

0.356 to 0.447..................................................      -4

0.448 to 0.562..................................................      -3

0.563 to 0.708..................................................      -2

0.709 to 0.891..................................................      -1

0.892 to 1.122..................................................       0

1.123 to 1.413..................................................      +1

1.414 to 1.778..................................................      +2

1.779 to 2.239..................................................      +3

2.240 to 2.818..................................................      +4

2.819 to 3.548..................................................      +5

3.549 to 4.467..................................................      +6



\1\ Ladj ave max=Lave max +C in dB.

Values in Table 2 were calculated from [C=10 log n/T] with intervals

  selected to round off values to the nearest whole decibel. The table

  may be extended or interpolated to finer interval gradations by using

  this defining equation.



    (3) Adjusted average maximum A-weighted sound level. The energy 

average level for the measured car coupling sounds is calculated to 

determine the average maximum sound level (Lave max). It is 

then adjusted by adding the adjustment (C) from Table 2 appropriate to 

the number of measurements divided by the duration of the measurement 

period (n/T), to obtain the adjusted average maximum A-weighted sound 

level (Ladj ave max) for car coupling impacts.