Western Railroad Discussion > Horn model on UP and BNSF ES44DC and ES44AC diesels

Early this morning before dawn , I was treated to the mellow sounds of BNSF GEVO horns , I think ES44AC or ES44DC power. They are the first GEVO's that came out, say in 2005? 
My question is what brand and model horn gives that mellow sound that is so pleasing to my ears ?   Were ES44DC or ES44AC BNSF and UP diesels equipped with these pleasing sounding horns ? If so, I would like to add models of ES44AC or ES44DC diesels to my HO model train collection. Thank you in advance. --Kelly



Edited 1 time(s). Last edit at 09/15/19 05:23 by UP951West.

UP951West Wrote:
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> Early this morning before dawn , I was treated to
> the mellow sounds of BNSF GEVO horns , I think
> ES44AC or ES44DC power. They are the first GEVO's
> that came out, say in 2005? 
> My question is what brand and model horn gives
> that mellow sound that is so pleasing to my ears
> ?   Were ES44DC or ES44AC BNSF and UP diesels
> equipped with these pleasing sounding horns ? If
> so, I would like to add models of ES44AC or ES44DC
> diesels to my HO model train collection. Thank you
> in advance. --Kelly

GE has almost exclusively used a Nathan K-5HL horn on US orders (and Canadian/Mexican orders that may operate in the US) since 2004 to meet Federal Regulation 49CFR229.129 regarding sound pressure level (SPL-in decibels or db) at 100 feet.

http://atsf.railfan.net/airhorns/k5hl.html

EMD has been using a Nathan K-5LLA horn to satisfy the same requirement.

http://atsf.railfan.net/airhorns/k5lla.html

There has been some variation is frequencies (the sound) produced by the horn bells, particularly the K-5HL.  Some of this is because of new tooling Windham Machine (the manufacturer of Nathan horns) installed a few years ago and closer attention to frequency specification of the horn bells. 

The sound produced by "good" horns can quickly become bad.  Oil fouling, cracked diaphragm discs, cracked, bent or broken off horn bells, snow/ice, carbon fouling (from the diesel engine exhaust) and accumulated dirt all affect the sound of a horn.  Unlike the old days when railroads had their own air shops for air related items on locomotives and cars including horns, the prevailing attitude now is if the horn makes a sound, any sound, then it's good to go.

If you're interested in the legalese of 49CFR229.129 go here: https://www.govinfo.gov/app/details/CFR-2011-title49-vol4/CFR-2011-title49-vol4-sec229-129
and click on "PDF" under "Download" on the left column for the entire rule.


d.

I thought each railroads (used to) have thier own unique set of horn notes?

Jim Baker
Riverside, CA

Some of the shortlines still have some variation however mainline roads seem to only have the variations noted previously.
In my opinion both horns produce decent sounds and a much more pleasant that the K3 horns that dominated on the new
locomotived several years ago. I particularily like the K5LLA on the new SD70ACE and AH locomotives because some sound 
very much like the old Nathan M5 horns (Photo). Unfortunately when these horns get fouled, they sound terrible.

Regards, Jim Evans
 

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RailRat Wrote:

> I thought each railroads (used to) have thier own
> unique set of horn notes?

Not really.  It's just that in the latter half of the 20th Century, there were enough different "stock" horns on the market that it seemed like railroads had their own custom blends.  The lowest cost, three-chime, "default" options like the Nathan M3, Leslie S-3L (Santa Fe, UP, Conrail), and Nathan/Airchime K3LA/K3HA (Santa Fe, UP, BN) were naturally the most common, but you didn't have to look far to find the same, more expensive 5-chime horn in use on more than one railroad.  The Leslie S-5T was Santa Fe's signature passenger airhorn, but was also used extensively by Frisco, MKT, KCS, N&W, and various CSX predecessors.  Western Pacific was known for its well-maintained Nathan M5's, but Southern Pacific used them too, as did Southern and Western Maryland - even Santa Fe had a few on passenger locomotives.  Rock Island was famous for its P5's, but Southern used them, too. 

In the diesel era, the only large railroad I know of that went to the trouble of requesting custom airhorn note combinations was Amtrak - four times, actually.  The first was the Leslie SL-4T used on the SDP40F's and nothing else.  Leslie horns in the 70's were notorious for fouling and going bad quickly, and Amtrak soon abandoned Leslie as a horn supplier. The second was the Nathan P01235 delivered on the E60 electrics that used the low-pitched 0 bell instead of the usual 4 bell (both played A, but the 4 bell was an octave higher than the 0).  Then there was the P5a delivered on the P30CH's, turboliners, and the first order of F40PH's that used a 4a bell playing A# instead of the 4 bell.  When it was made to spec, the P5a sounded great, but Nathan started getting sloppy with their molds in the 70's, and the P-horns in general started coming from the factory out-of-tune and sounded horrible.  There was essentially no way to re-tune them, so we endured a couple of decades of weird P3's on SP, ear-splitting P5's on NS, and a mercifully small quantity of bad P5a's on Amtrak.  Finally in the mid-70's, Amtrak's Deane Ellsworth requested a retuning of the Nathan/Airchime K5L used in Canada to a more "American sounding" major chord.  The result was the K5LA, introduced on the second order of F40PH's and  Amtrak's standard horn ever since.  At the time, Chessie was looking for an alternative to the Leslie S-5T's they were using, and they quickly adopted the K5LA as well.  Eventually NS also joined the fold.

Like the P-horns, the K-horn patterns gradually started drifting out of spec.  The issue was more noticeable on the K3's, with the K5's by and large still sounding pretty good.  This was the situation in the early 2000's when the current version of 49CFR229.129 was promulgated.  The old version had only specified a minimum decibel requirement, easy to meet with just about any horn, but the new version had a decibel range, specifing both a minimum and maximum level.  The locomotive builders each found one horn configuration that worked for their standard models, and every railroad ordering those locomotives got that particular horn.  For the GE Evolution Series, that was the Nathan/Airchime K5HL with the 3 bell facing forward and the 1L, 1, 2, and 4 facing aft.  From the beginning of GEVO production in 2004 until roughly the summer of 2007, the K5HL horns sounded like a lower-pitched version of the K5H that had been common on BC Rail in Canada and also showed up in the US on some GE products in the late 80's and early 90's (SP and Susquehanna Dash 8-40B's, NS Dash 8-32B's, CNW Dash 9-44CW's and AC4400CW's).  The early K5HL did indeed have a beautiful, mellow sound...but it was the result of the K-horn patterns drifting out of spec:

http://atsf.railfan.net/airhorns/k5hl_up.mp3

In 2006, Microprecision LLC acquired both Airchime and Nathan (who made Airchime-designed horns in the US under license), and they soon brought the horn patterns back into spec.  This had a beneficial effect on the K5LLA used on EMD SD70ACe's, giving them a more pleasant sound very reminiscent of the beloved but tempermental and nearly-extinct M5.  The K5HL, though, went from a mellow sound to something much more ominous and menacing, reminiscent of (but better than) the Leslie S-5T in its later years:

http://atsf.railfan.net/airhorns/k5hl5bnsf.mp3

It's not a bad sound, especially for a warning device, but I do prefer the older sound.

Very interesting post about horns on locomotives. My peronal favorites are the Nathan P5 used on some Norfolk Southern (ex Southern Rwy) engines. Also the Union RR and Southern Pacific P3 horns. Beautiful sounds from those horns. Leslie S3 horns on Santa Fe locomotives were cool too.

SantaFeRuss

Thanks For All That Info guys, As A Musician, then railfan, I was always aware of different sounding horns on locomotives, plus I grew up hearing dad's trombone playing, and he played big band music from the 1940's all the time!

So what was it that made SP horns sound so distinctive and recognize able (to my ear anyway)??

Jim Baker
Riverside, CA

RailRat Wrote:
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> So what was it that made SP horns sound so distinctive and recognize able (to my ear anyway)??

They did the same to me. Don't know what it was, but it just said SP. I'll throw this thread at you.

https://www.trainorders.com/discussion/read.php?1,1413968,1413968#msg-1413968

SP 8577 on the point of the MNWRV climbing up the Altamont Pass shortly after midnight on 5/24/07. I was at the throttle and it was the last time I had an unpatched SP unit on the point, and it still had a P3! Throw in three EMD 645's in run 8 and it was a nice night.

 

RailRat Wrote:

> So what was it that made SP horns sound so
> distinctive and recognize able (to my ear
> anyway)??

The Nathan P3, which was SP's main airhorn in its final decades, wasn't used to any great extent by any of the other large railroads in California.  Shortline Stockton Terminal & Eastern had P3's on most of its Alco switchers in the 1990's, but Santa Fe, UP, and WP barely acknowledged that the P-series horns even existed.  The Northern Pacific did use the P3, so the Northern California guys might catch one on a BN unit coming down the Inside Gateway via WP.  Elsewhere, I recall Green Bay and Western had P3's on its red Alcos, and Illinois Central had a mix of P3's and Leslie S-5T's, but for California, the vast, vast majority of P3's were to be found on SP.

By the way, the horn's inventor, Bob Swanson, reportedly didn't like the P-series very much.  He developed them from a truck horn to provide a low-cost, low-maintenance alternative to the M-series to compete with Leslie's Supertyfons.  While the P3 and P5 played the same notes as the M3 and M5, the P's were much sharper and brassier in tone, and Swanson claimed the P stood for "P!$$ POOR!"  A good P3 or P5 can be pleasant to hear, but the so-called "new castings" horns produced after the patterns started going out-of-spec were...well...something only die-hard SP fans could love.

So, was your dad more of a Glenn Miller, a Tommy Dorsey, or a Jack Teagarden?