Compliance Deadline Countdown
Compliance is Due:
Federal Rail Administration, CFR 49 Part 229
Final Rules on the use of Locomotive Horns at Highway-Rail Grade Crossing
(Relative to horn testing
§ 229.129 Locomotive horn.
(a) Each lead locomotive shall be equipped with a locomotive horn that
produces a minimum sound level of 96 dB(A) and a maximum sound level of 110
dB(A) at 100 feet forward of the locomotive in its direction of travel. The
locomotive horn shall be arranged so that it can be conveniently operated
from the engineer’s usual position during operation of the locomotive.
(b)(1) Each locomotive built on or after September 18, 2006 shall be tested
in accordance with this section to ensure that the horn installed on such
locomotive is in compliance with paragraph (a) of this section. Locomotives
built on or after September 18, 2006 may, however, be tested in accordance
with an acceptance sampling scheme such that there is a probability of .05
or less of rejecting a lot with proportion of defectives equal to an AQL of
1% or less, as set forth in 7 CFR part 43.
(2) Each locomotive built before September 18, 2006 shall be tested in
accordance with this section before June 24, 2010 to ensure that the horn
installed on such locomotive is in compliance with paragraph (a) of this
(3) Each remanufactured locomotive, as determined pursuant to § 229.5 of
this part, shall be tested in accordance with this section to ensure that
the horn installed on such locomotive is in compliance with paragraph (a).
(4)(i) Except as provided in paragraph (b)(4)(ii) of this section, each
locomotive equipped with a replacement locomotive horn shall be tested, in
accordance with paragraph (c) of this section, before the next two annual
tests required by § 229.27 of this part are completed.
(ii) Locomotives that have already been tested individually or through
acceptance sampling, in accordance with paragraphs (b)(1), (b)(2), or (b)(3)
of this section, shall not be required to undergo sound level testing when
equipped with a replacement locomotive horn, provided the replacement
locomotive horn is of the same model as the locomotive horn that was
replaced and the mounting location and type of mounting are the same.
(c) Testing of the locomotive horn sound level shall be in accordance with
the following requirements:
(1) A properly calibrated sound level meter shall be used that, at a
minimum, complies with the requirements of International Electrotechnical
Commission (IEC) Standard 61672-1 (2002-05) for a Class 2 instruments.
(2) An acoustic calibrator shall be used that, at a minimum, complies with
the requirements of IEC standard 60942 (1997-11) for a Class 2 instrument.
(3) The manufacturer’s instructions pertaining to mounting and orienting the
microphone; positioning of the observer; and periodic factory recalibration
shall be followed.
(4) A microphone windscreen shall be used and tripods or similar microphone
mountings shall be used that minimize interference with the sound being
(5) The test site shall be free of large reflective structures, such as
barriers, hills, billboards, tractor trailers or other large vehicles,
locomotives or rail cars on adjacent tracks, bridges or buildings, within
200 feet to the front and sides of the locomotive. The locomotive shall be
positioned on straight, level track.
(6) Measurements shall be taken only when ambient air temperature is between
32 degrees and 104 degrees Fahrenheit inclusively; relative humidity is
between 20 percent and 95 percent inclusively; wind velocity is not more
than 12 miles per hour and there is no precipitation.
(7) With the exception of cab-mounted or low-mounted horns, the microphone
shall be located 100 feet forward of the front knuckle of the locomotive, 15
feet above the top of the rail, at an angle no greater than 20 degrees from
the center line of the track, and oriented with respect to the sound source
according to the manufacturer’s recommendations. For cab-mounted and
low-mounted horns, the microphone shall be located 100 feet forward of the
front knuckle of the locomotive, four feet above the top of the rail, at an
angle no greater than 20 degrees from the center line of the track, and
oriented with respect to the sound source according to the manufacturer’s
recommendations. The observer shall not stand between the microphone and the
(8) Background noise shall be minimal: the sound level at the test site
immediately before and after each horn sounding event shall be at least 10
dB(A) below the level measured during the horn sounding.
(9) Measurement procedures. The sound level meter shall be set for
A-weighting with slow exponential response and shall be calibrated with the
acoustic calibrator immediately before and after compliance tests. Any
change in the before and after calibration levels shall be less than 0.5 dB.
After the output from the locomotive horn system has reached a stable level,
the A-weighted equivalent sound level (slow response) for a 10-second
duration (LAeq, 10s) shall be obtained either directly using an
integrating-averaging sound level meter, or recorded once per second and
calculated indirectly. The arithmetic-average of a series of at least six
such 10-second duration readings shall be used to determine compliance. The
standard deviation of the readings shall be less than 1.5 dB.
(10) Written reports of locomotive horn testing required by this part shall
be made and shall reflect horn type; the date, place, and manner of testing;
and sound level measurements. These reports, which shall be signed by the
person who performs the test, shall be retained by the railroad, at a
location of its choice, until a subsequent locomotive horn test is completed
and shall be made available, upon request, to FRA as provided by 49 U.S.C.
(d) This section does not apply to locomotives of rapid transit operations
which are otherwise subject to this part.
5. The entry for § 229.129 “Audible warning device” in appendix B to Part
229 is revised to read as follows:
Appendix B to Part 229 – Schedule of Civil Penalties
|229.129 Locomotive horn:
|(a) Prescribed sound levels Arrangement of horn
|(b) Failure to perform sound level test
|(c) Sound level test improperly performed
|Record of sound level test improperly executed, or not
Issued in Washington, DC on August 7, 2006
Joseph H. Boardman
The above text and contents extracted from FRA, DOT, 49 CFR Parts 222 & 229