The Hexatone H6 was developed in 1948 and 1949 by Robert E Swanson. Four of these great horns were produced over that time. The first H6 was cast iron, and was supposedly scrapped, with the rest being aluminum. H6's serial numbers 1 and 3 were part of the AirChime collection, which was sold in 2008 to a private collector. There are rumors about the disposition of serial numbers 2 and 4, which that range from someone at AirChime stealing one to one being in a museum in Great Britain. None of these stories are more than rumors, though, and have not ever been confirmed. One other interesting story with the H6's is that only four are on record, and since the first was known to be cast iron, why is the existing serial number 1 aluminum? A possible theory is that one of the other two H6's was returned to AirChime after the cast iron #1 was scrapped, and the serial number was ground off and reset to 1. This is plausible, as the serial number plate on the existing number 1 is thinner than on number 3. Anyway, regardless of the stories and speculation, it's great that at least two of these historically invaluable horns have managed to survive and have been restored for people to hear yet again!

The bells on an H6 are arranged in a hexagonal pattern, which accounts for its immense height, with the largest bell in the bottom center. All the bells are welded together, are non-reversible, and have copper tubing running from a central manifold to each bell. Also, the orifices for each bell are different, resulting in a balancing of the low and high tones. The bells on an H6 are adjustable as well; by screwing the diaphragm housing on or off the bell, the length of the bell could be changed, effectively raising or lowering the pitch of that bell. By adjusting the heads on this horn, it was possible to come up with many different musical chords, one of which was the long-bell SP/Nathan 6-chime steam whistle chord. The H6 was originally to sound a C# diminished chord, which was Robert Swanson's "favorite" chord, designed using ancient Chinese musical theory. (This chord was also used on the P1234A5 horn.) Over the years, other accounts tell of these horns sounding C D# F# A C and D#, though as noted many tunings were possible.

The H6s were not very practical, as they stood nearly two feet tall, could easily be snagged by items overhanging the railroad tracks, weighed in at over 50 pounds, and didn't use a standard horn mounting flange. All were supposedly used on slow-speed shortlines, such as the Pacific Great Eastern in Canada, and one supposedly survived in service at least into the late 50's or 60's. Serial #1 is also known to have been used as a test on the Simpson Timber Railroad in Washington State.

One final note is that the H6s were produced up through March 1949, before AirChime's inception, and before Nathan got into the horn business. Neither AirChime nor Nathan should be associated with the H6; this horn was Robert Swanson's creation.

Following the H6's were the H5s, which were the first chime horns ever built in any large production number by AirChime. It also holds the distinction of the world's first 5-chime horn. It has five bells, and Swanson's original tuning was C# diminished (C# E G A# C#). Basically a five-note version of an H6, the H5 also shares this horn's unique "outdoor plumbing" to each bell and variable orifices, but is shorter and uses a standard horn mounting flange. The bells are also welded in place, around the #1 bell, and are non-reversible. As on the H6, the bell lengths on the H5 could be adjusted to change the pitch of each bell, fixed in place with a bronze lock nut. Some common chords produced by H5s were A Major 6th (C# E F# A C#), A Major 7th (C# E G A C#), C# diminished, and more. Over time, some have come to result in an odd combination, sounding C# D# F# A and C#. The back caps on H5s and H6s were also quite unique in that a spanner wrench is not needed to remove them. Instead, these caps had six tabs protruding back along the outer circumference of the cap, which were used to "grip" and rotate the cap. A correctly-sized block of wood could do the job nicely.

There were several runs of H5s, the first being serial numbers 7-11 and 22-24, have "HEXATONE H5" cast into the #1 bell on one side and "HEX TONE H5" on the other side. These horns also had "6" cast into the smallest bell's back cap instead of "5", as the smallest bell was in fact the 6 bell from the H6, not the 5 bell. This was corrected in the castings to "5" in later runs of the H5. Serial numbers 41-55 have "Nathan Airtone H5" cast into their #1 bells. The third run, serials 63-76, have "Nathan H5 Five Tone" cast. The last H5s were in the serial number ranges of 163-166 and 170-195. These numbers were taken from Robert Swanson's personal inventory of AirChime serial numbers. Note that for six of these the records aren't clear, though they are known to be five chimes and appear in the middle of other H5 orders placed on the same dates, and so are assumed to also be H5's. What confuses the issue further is that until Swanson's records were available, it was believed that 88 H5's were produced, not the 67 as shown in his records. In addition, an H5 with serial number 125 exists today, though according to Swanson's records, this was an SN1 (maybe a single-bell N horn?). Maybe serial number 125 is a Nathan serial number? We do know that 57 of the H5's produced were purchased by Nathan, some of which were sent directly to General Motors (7 by Holden, as well). Perhaps the true story of how many horns were built, and which serial numbers they hold, will never be fully known.

H5s were used on several different roads, though the Western Maryland purchased the most. The WM even had pairs of H5s on some of their power, one facing forward, one facing backwards! A few H5s were known to have service lives up through the 1980s, with one surviving into 200x some time, though since then the only known survivors have been in the hands of collectors.

Of note is that there were a couple dozen single-bell H horns sold, typically using the #2 bell. These horns had a mount that used a stanard 4-bolt horn pattern at the base, and a type of clamp at the top which would just go around the bell to fix it in place. The copper tubing was plumbed from an outlet on the base into the head, just like the H5s. While they are cataloged as S-model horns, they are in fact H bells and heads. I assume the S indicated that the horn is a single-bell horn, not the type of bell/head used for the horn (i.e. H, N, M, etc.). (Later, designations like NS-2 and MS-1 were used to indicate the model and the fact that the horn is a single bell and not a chime.) At least one example of an S-2 survives today. Likewise, there were two- and three-chime variants of the H5 horn, with a total of 4 H2's and 8 H3's produced according to Swanson's records. None of these chimes are known to have survived.

		h5_030614_1.jpg	the bottom of an H5 showing how the bells are welded together, and how the mouth of the #1 bell is offset from the other four, accommodating a tighter fit of all the bells
		h5_030614_2.jpg	a rear view of the H5 giving a good overall picture of how one is arranged
		h5_030614_3.jpg	this side view of Jim Smith's H5 shows the markings on the #1 bell, including the stamped serial number - #24
		h5_010519_1.wav	Bill Williamson's H5 tuned to A Major 7th, recorded at the 2001 Altoona H&W Fair
		h5_030614_3.wav	Jim Smith's H5 at the Oak Ridge 2003 blow - It is tuned to Swanson's original H5 chord according to score marks on the bells and chambers, but no longer blows the intended C# diminished

A5

The A5 air horn is actually a Nathan creation, and has nothing to do with AirChime or Swanson. Nathan was trying to improve on the H5 and came up with this horn. The main difference with the H5 is that the bells are reversible. The first A5 was assembled from five single H horn bells, mounted on a braket that most closely resembled the S-2 braket (see above). The five bells were clamped in place just like the S-2, which made them reversible; unclamp the bell reverse it, and clamp it back down. However, it wasn't just that easy to reverse the bells, as copper plumbing was still required to each head.

There is at least one example of an M3 that used heads that were intended for the A5 horns (there are blocks available to be drilled and tapped for air inlets), and so it is uncertain whether many or most of the A5s produced actually used H or M bells/heads. My personal opinion is that if the M horn was available, there would be no need to apply the outdated A-series technology to an M head. Just as speculation, perhaps the M head was developed and shared with Nathan prior to the M-series horns' unveiling? The answer may never truly be known. Anyway, of interest is that the M heads that Nathan supposedly intended for the A-series horns had two blocks that could be drilled and tapped for air inlets unlike the H heads' one. In the end, though, the A5 line ended after about 25 or so were produced. None are known to survive.

m3_kanne_1.jpg

while not an A5, Ken Kanne's early round-base M3 has the blocks cast into the tops of the #1 and #2 heads which would have been drilled and tapped for airlines if used on an A5

N3

The N3 was Swanson's first production 3-chime horn in any great numbers (as noted above, eight H3's were produced prior). It does not have external plumbing, like the H6, H5, and A5, but rather is the first horn to use the manifold as both a mount for the horns as well as an air manifold. The horn has a very similar appearance to the M3, and even plays the same chord - C# E and A. Like the H6 and H5, the N3 uses a diaphragm assembly that is riveted together, not bolted like the M series. There are a few differences, though, from other early AirChime models. First, the bell throats extend through the manifold and contact the heads, very similar to SuperTyfon bells. As for visual differences, the manifold has more gradual slopes surrounding the place the #1 bell attaches, the heads have a small tab on the top of them, and the back caps are the same style as the H5 and H6 back caps. Also, the bells do not have any markings on them, and the hex-head cap screws joining the heads and bells to the manifold can be seen sticking out of the base of each bell. Of particular interest is that the N3 was a marvel of machine work, as while the bells may seem loose in the manifold, they mate perfectly and do not leak any air, WITHOUT the use of any gaskets! However, this close clearance in machining may have also been the reason for the short production run and the introduction of the M series horns.

The N3 was more of a filler model than a long-range production model, which the M series horns were to be. Despite the tight tolerances of the machine work involved in these horns, 61 were produced, in the serial number ranges of 77-81, 88-115, 136-162, and 167. Strangely, number 88 (which survives today) was the prototype. It is believed that for whatever reason it was only given a serial-number after the first batch had already gone out. Note that like the H5's, for three of the N3's the records aren't clear in Swanson's logs, though they are known to be three chimes and appear in the middle of other N3 orders placed on the same dates, and so are assumed to also be N3's. There were also a couple single-bell N horns produced, though none are known to have survived. Thankfully, two N3 horns do survive in private collections, and are two of the most beautiful horns I have ever heard. Many thanks to Bill Williamson, Eric Marks, Deane Ellsworth, and Jodie Wells for their trip to AirChime in 2007, which in part yielded this new information on the H and N series horns!

		altoona2001.jpg	this picture, from Altoona 2001, shows several rarities, including two H5s (one on Bill's tailgate, the other mounted), a 0-bell M5 (on the ground), and an N3 (also on the ground) - the second H5, the 0-bell M5, and the N3 belong to Fred Berry
		n3_020929_1.wav	Brent Lee's N3 recorded at about 1AM during his 2002 Cape Horn Honk, tuned by Fred Berry

J3 Snowplow Whistle

The J3 was a short-lived model that was introduced just months before the K series. This horn was designed to be a low-maintenance alternative to the M3H for use on Canadian snow plows. It blows a D# minor chord, and at a quick glance looks like a K3. The only external differences between the J3 and K series horns are a triangular base (which was also used for early K3s) and "AirChime Snowplow Whistle" cast into the #1 bell (though at least a few J3's have just "1J" cast in the side). The insides of the J3 are slightly different from the K series. First, there is only one diaphragm disk in each bell (as opposed to the K's two). Also, there is no diffuser ring inside, and a rubber nozzle is used similar to P horns. The sound of the J3 I believe is a magnificent, mellow chord when compared to a K3 -- not as loud, but hauntingly sweet. Thankfully there are a small handful that are preserved in collector hands for all to enjoy.

There were apparently more than just the 1, 2, and 3 bells produced in the "J" style. Evidently all bells from 1L through 5 were produced, though no J-series horns other than the J3 were ever catalogued or recorded. There were a lot of changes in the AirChime offerings in the early 1950s, with the M3H being offered for the first time in March 1952, the J3 a year later, and the K3 another year after that. Apparently, when the K3 was introduced, the J3 was dropped, though in that short time span, a couple hundred J3s were indeed recorded in Swanson's logs! Also, several early K horns have odd internals which more closely match the J3 internals, and so the bells which were not used on J3s (and maybe even some 1, 2, and 3 J bells) may have been placed on early K horns either as prototypes, or to just get rid of the bells.

MK series

The MK series horns, which can be read about in greater detail on the K series page, are included here primarily due to their rarity. The MK5H and MK3H horns were introduced in 1956, but replaced a year later with the "set-screw" variant of adjustable K horn back caps. The MK horns were produced in two short runs, and are actually far outnumbered by J3 snowplow whistles in terms of quantities produced/sold!

last updated 10/19/09