Nostalgia & History > K5LA Airchime by Nathan Manufacturing, Inc, 1979 -- Bill Howes

Here is Bill's interesting story for this photo:

As part of a grade crossing safety initiative in the mid-1970's, the Chessie System reviewed the reliability and effectiveness of the air horns then in use on its diesels. This led to the adoption of the Nathan Airchime K5LA tuned to a five chime chord that was found to be more "strident" (that is, attention grabbing) without being offensively louder. The "K" indicates that it based on a Canadian design noted for its reliability. The "5" is for the five bells, all facing in the same direction, "L" means it has a low profile. "A" stands for its American tuning. The horn also employed a modulating valve that allowed it to be blown at various levels of loudness and for a skilled engineer to "quill" the horn like a steam locomotive whistle. The K5LA was introduced in 1977 on Chessie's new SD40-2's.


Thanks Bill,
Marty Bernard



Edited 1 time(s). Last edit at 10/11/20 18:20 by MartyBernard.

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I think they did the tests on different horns on the WM outside Hanover PA.

The first one i heard was GP40-2 4308 crossing Dixie Highway in Hamilton Ohio.
It left quite an impression on me.
It had such range of modulation.
I've been a fan of the K5LA ever since.
I have an original Chessie K5 in my garage.

Posted from Android

I believe the "K" stands for "Kettle Drum" effect.
So I've heard.

Posted from Android

What musical notes would they represent?

I've been told the K5LA plays a B major 6th chord- D#, F#, G#, B, D# (octave).

John
 

I have a scratch built carousel band organ.  I'll try those notes in the reed section.  Thanks for the info.
Bob
 

You're correct.  It's got nothing to do with "Canadian."  

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90mac Wrote:
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> I believe the "K" stands for "Kettle Drum"
> effect.
> So I've heard.
>
> Posted from Android

In a presentation to the Chesapeake Division Railroad Enthusiasts in the early 1980s, Bill Howes also pointed out that among the KFLA's attributes was its similarity in sound to a number of multi-chime steam whistles.

Art House

They do have a pleasing sound to them. Thanks for sharing.

MartyBernard Wrote:

> The K5LA was introduced in 1977 on Chessie's new SD40-2's.

The rest of the story, according to Deane Ellsworth anyway, was that the K5LA was actually developed for Amtrak. 

The horn was based off of the minor-key Airchime K5 that had been available in Canada since 1954.  The story of that horn was that Airchime's guiding force, Bob Swanson, had wanted to market a locomotive horn that was lower-maintenance than his melodious but demanding M-series horns, and more pleasing than the reliable but tinny P-series horns that were based off a truck horn design.  Swanson came up with his "kettle drum" diaphragms - two metal disks with a ring of silicone in between - to try to make the sound of the horn rise like a steam whistle as more air pressure was applied.  The effect didn't pan out as well as he intended, but the horns did work well and sounded a sweeter tone than the P-series. 

In the mid-70's, when Deane Ellsworth went to work for Amtrak, the carrier's new locomotive fleet consisted of SDP40F's sporting unpleasant, squeal-prone Leslie SL-4T's, E60 electrics with Nathan/Airchime "0-bell" P5's, and P30CH's, turboliners, and the first 30 F40PH's with Nathan P5a's.  In the interest of getting better horns on Amtrak's next round of locomotive purchases, Ellsworth convinced Bob Swanson to modify the #3 and #4 bells on the K5 to play a brighter, "happier" sound.  The K5 had a relatively tall manifold with three horn bells stacked above two.  Amtrak's clearance diagrams dictated a lower-profile arrangement, so the low-arc "L" manifold was developed (the old, "high" manifold was thereafter designated the "H" manifold).  The first examples of the resulting "American-tuned" K5LA were tested on the Chessie, who liked them so much compared to the squeal-prone Leslie S-5T's they had been using that they specified the horn for their new locomotives as well.  Chessie's SD40-2's thus beat Amtrak's second order of F40PH's for the title of first new locomotives delivered with the K5LA.

I only met Ellsworth once hanging with the late Steve Hoskins.

Posted from Android

It was always a pleasure to catch a unit with the K5LA's with a quill valve. Man could you make some music!

Most of the B&O and Chessie units I saw had S3L horns prior to the K5LA coming out. Some C&O and WM units had S5T's. I remember hearing the K5LA when it was new. A nice change from the older horns at the time. But after 40+ years, I'm kind of tired of them now. I like the horns NS has on their 8000 and 3600 series GE's.