Canadian Railroads > Horns on the new GE's for CN

Ok, I was out and about on Friday, May 22, 2015, and got a few photographs of a couple of fairly new GE Loocmotives sitting at the Fuel Dock in Battle Creek, Michigan.

These first three photographs are of the CN 2822, from a distance, and two close ups of the horns on top of the car body.  I have no questions about these horns, but I do question the horns on the CN 2943, which was MU'd behind the CN 2822, and was facing the opposite direction.

Continued .....

Ron

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Both the CN 2822 and the CN 2943 have five trumpet horns. On the CN 2822 there are three trumpets facing forward, with two trumpets facing rearward.

But on the CN 2943 there is only one trumpet facing forward, while it has four trumpets facing rearward.

Could this locomotive possibly have been built with the horns incorrectly installed?  Has anyone seen any of these with the horns set up like this?  I personally think the horns were installed incorrectly.

Any thoughts on these two different locomotives and the horns on them?

Ron

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The horns on these units are GPS controlled, they always face the same direction.  Something to do with the curvature of the earth and the way sound travels.  It is some kind of Eistein theory that is being put into practice by CN.

YUKON  YOU ARE SOME SMART. HOW DID YOU KNOW ALL THAT ABOUT THE HORNS? IT WAS SUPPOSED TO BE A CN SECRET.
Bill Turner
Hamilton Ont.

The locos were assembled in China and one of them was on the bench at 3.30pm, Friday afternoon.

Rick

Quieter for the crew if the chimes face rearward possibly? 

Mike N.

Ron,

CN 2822 is equipped with a Nathan P5R24 horn, likely not original but a replacement.  IC was a common user of this horn and wouldn't surprise me if it came off their parts shelf.
CN 2943 is equipped with a Nathan K5HLR2 horn which is standard issue these days on GEs.  This horn is purposely mounted backward with only the #2 horn bell facing forward so the sound pressure level meets US Federal standard 49CFR229.129.

If you're interested in reading the US Regulation, here is a link:
http://www.ecfr.gov/cgi-bin/text-idx?SID=7102a91f374865823960b737652cf042&mc=true&node=se49.4.229_1129&rgn=div8

Hope this helps.

daniel

edited to add "US" Federal standard
edited second time to add link to US Title 49 Code of Federal Regulation



Edited 2 time(s). Last edit at 05/23/15 19:24 by 251F.

I have some pictures buried somewhere, of the same thing on some CP GEs.   I'll have to try to find them.  Didn't look right to me either.   I thought the main idea was to project as much sound as you could, toward the crossing you were approaching.   Why bother putting on five chimes, only to send most of your available sound, rearward ?   I know they can still be heard, but they are surely louder when pointed bell end forward.   I've tried it with my own set of horns, and there's a definite difference.

Craig Hanson
Vay, Idaho
 

hawkinsun Wrote:
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> I know they can still be heard, but
> they are surely louder when pointed bell end
> forward.  
>
> Craig Hanson

This was done so the following requirement was met.  GE and EMD did a lot of testing to find the magic combination that met the US Federal requirement.  It was not done arbitrarily.

Here are some snips from the link to the Title 49 Code I posted above.

daniel

§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.

(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 instrument.  (Generally a Bruel & Kjaer 2250: http://www.bkhome.com/Products/handheld-instruments/sound-level-meters/sound-level-meters/type-2250, about $5500 for the base model)

(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.(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.