Code of Federal Regulations Title 49. Transportation 49 CFR Pt. 299, App. B—CAB NOISE TEST PROTOCOL

This appendix prescribes the procedures for the in-cab noise measurements for high-speed trainsets at speed. The purpose of the cab noise testing is to ensure that the noise levels within the cab of the trainset meet the minimum requirements defined within § 299.431(h).

A. Measurement Instrumentation

The instrumentation used shall conform to the requirements prescribed in appendix H to part 229 of this chapter.

B. Test Site Requirements

The test shall meet the following requirements:

(a) The passenger trainset shall be tested over a representative segment of the railroad and shall not be tested in any site specifically designed to artificially lower in-cab noise levels.

(b) All windows, doors, cabinets, seals, etc., must be installed in the trainset cab and be closed.

(c) The heating, ventilation and air conditioning (HVAC) system or a dedicated heating or air conditioner system must be operating on high, and the vents must be open and unobstructed.

C. Procedures for Measurement

(a) L_Aeq,T is defined as the A–weighted, equivalent sound level for a duration of T seconds, and the sound level meter shall be set for A–weighting with slow response.

(b) The sound level meter shall be calibrated with the acoustic calibrator immediately before and after the in-cab tests. The calibration levels shall be recorded.

(c) Any change in the before and after calibration level(s) shall be less than 0.5 dB.

(d) The sound level meter shall be located:

(1) Laterally as close as practicable to the longitudinal centerline of the cab, adjacent to the driver's seat,

(2) Longitudinally at the center of the driver's nominal seating position, and

(3) At a height 1219 mm (48 inches) above the floor.

(e) The sound measurements shall be taken autonomously within the cab.

(f) The sound level shall be recorded at the maximum approved trainset speed (0/–3 km/h).

(g) After the passenger trainset speed has become constant at the maximum test speed and the in-cab noise is continuous, L_Aeq,T shall be measured, either directly or using a 1 second sampling interval, for a minimum duration of 30 seconds at the measurement position (L_Aeq, 30s ).

D. Reporting

To demonstrate compliance, the railroad shall prepare and submit a test report in accordance with § 299.613. As a minimum that report shall contain—

(a) Name(s) of person(s) conducting the test, and the date of the test.

(b) Description of the passenger trainset cab being tested, including:  Car number and date of manufacture.

(c) Description of sound level meter and calibrator, including:  Make, model, type, serial number, and manufacturer's calibration date.

(d) The recorded measurement during calibration and for the microphone location during operating conditions.

(e) The recorded measurements taken during the conduct of the test.

(f) Other information as appropriate to describe the testing conditions and procedure.