LocomotiveHorns.info - Tyfon   

Leslie Tyfon air horns were some of the earlier air horns to appear on the railroads, dating back as far as about 1934. Only Westinghouse, and a few other manufacturers who were not well known, preceded them. All of the Tyfon series were single-note "honkers". The horns were very simple in that the only parts were the horn itself, a screw-in back cap, and either a single or multi-leaf diaphragm, making the horns consist of very few parts. The "sound chamber" and "base" portion of the horn was cast separate from the bell, which treaded to the base. But once together, there is no need to take them apart ever again. In fact, on the Tyfons that I've seen, the pin used to keep the bell from unscrewing from the base is welded in place, if not the whole joint itself, making the bell and base a permanent fixture.

The most popular of the Tyfon series for railroad use was the Tyfon A-200-156. This was Leslie's deep-note horn for road locomotives. The A-200 appeared on many early diesels and electric locomotives from the 1930s through the 1950s. Locomotives that had A-200s included the popular GG1s, ALCO RS1s, RS3s, PAs, FAs, EMD E and F units, and GP7s to name a few. Some late-1940s steam locomotives even included A-200 horns on them, such as the Southern Pacific Daylight locomotives like 4449. Leslie A-200s can still be heard on some older locomotives, though their numbers are dwindling.

A-75 Dual Tone For general railroad use, A-200s were most common. A-125s were not as common, though frequently used, usually showing up on switchers or other smaller engines. A-75s were least common, and were usually used as a secondary horn on the back of a switcher, or as a back-up horn on the backs of old covered wagons. Also marketed, though quite rare, were dual-tone Tyfons, which consisted of two Tyfons mounted on a single plate. I know of at least three surviving dual A-75s, and know that dual A-125s, dual A-200s, and A-125/A-200 combinations were also used. Even some late model steam engines used pairs of Tyfons! A single A-200 on a steam locomotive wasn't common, per say, but much more common than was an A-200 with an A-125, or even a pair of A-125s!

a125_2001_1.jpg my dad's A-125-LP, showing the construction of the diaphragm housing with screw-on back cap, a feature common to all Tyfon horns
a125_020518_1.wav the A-125 needs some adjusting on the back cap
a200_weiler_1.wav an A-200-156 in active service (Copyright Norman Weiler, used with permission)


By 1950, or possibly a little earlier, Tyfon horn designations had developed as follows for single-note horns. (Earlier on, there were different designations, as shown below.) Since it can get confusing, I've color-coded the designation.
Start with the letter A, representing the medium used to blow the horn - air. (Leslie also made steam horns for marine use; these started with S.) The A is followed by a number equaling the diameter of the diaphragms in millimeters (75, 125, or 200). In general, the larger the number, the lower in pitch and louder the horn. Next you have another number, which is the frequency - or pitch - of the horn in hertz; the 156 above represents a pitch of 156Hz, or D# below middle C. Then you have a letter corresponding to diaphragm material. P is for plastic (a phenolic laminate), R is for rubber-faced plastic, and M is for metal (two and three leaf bronze diaphragms were both possible). A fourth designation of C was also used for horns built for Chime-Tone configurations (see below), to indicate "Chime-Tone diaphragm material", though it is unclear what this refers to. By this time (1950), nearly all A-125 and A-200 horns produced used the rubber-coated plastic diaphragm (and so C is probably synonymous with R), unless the horn was for high pressure as found in some marine uses, which still required bronze diaphragms. The plastic diaphragms could be better described as "a very fine weave linen cloth impregnated with phenolic", similar to the backs of older TVs, but much stronger. Finally comes another letter representing the material of the horn (A for aluminum, B for bronze). However, A-75s were never available in any material other than bronze. So a Leslie Tyfon A-200-156-PA would be an aluminum Tyfon air horn pitched at 156Hz with a 200mm diameter plastic diaphragm. A Tyfon A-75-440-MB would be a bronze Tyfon air horn pitched at 440hz with a 75mm diameter metal (bronze) diaphragm.

There were many earlier designations for Tyfon horns; I will try to cover some of the differences here. First, early Tyfon horns were either bronze or cast iron, not aluminum, and didn't include the "A" or "B" casting material designation. The pitch designation in hertz wasn't included either, and didn't come into play until about 1950. Instead, the letters "HH", "H", "M", "L", and "LL" would be placed in front of the diaphragm material letter, indicating extra high, high, medium, low, and extra low pitch, respectively. However, not each model of Tyfon used all these pitch designations. For instance, the A-75 and A-200 were offered in only three possible pitches. Also, I've been told that the A-125-LL was only available as a special order item. As an example of these designations, my father's A-125-LP is a bronze Tyfon air horn with a 125mm plastic diaphragm, tuned to the "low" pitch for A-125s, which is 247Hz, or B below middle C. These designations were common throughout the 1940s.

Even earlier, in the 1930s, still other designations were used! "RR" seemed to be the common tail to all designations of this time period, assumed to signify "railroad" use. Also, in the 1940s, some A-200s were designated with a "Y" as well. Though I'm not sure what it stands for, those with the "Y" are listed has using less air to operate than those without, though no other differences are apparent. Some other designations used here and there throughout the Tyfons' lifetimes were "C", "T", and "X". Unfortunately, I don't know what these would have meant, though one may have been a designation for a curved, marine-use A-200 model that appeared on many WWII-era submarines. There are even more designations, though they are more rare to come across. That's a lot of information, so here is a chart that is accurate to the best of my knowledge. It is unknown whether the horns associated with the empty spaces ever existed during the eras listed. Lengths listed include the diaphragm housing all the way to the end of the bell flare, but do not include the tabs protruding out of the back cap.

(in Hertz)
  A-75-LL A-75-262 262Hz C 20-21/32"
A-75-M RR (?) A-75-L  A-75-330 330Hz E 16-11/16"
A-75-H RR (?) A-75-H  A-75-440 440Hz A 10-3/8"
A-125-M RR A-125-LL A-125-206 206Hz G# 23"
A-125-H RR A-125-L  A-125-247 247Hz B 19-1/4"
  A-125-M  (?) A-125-277 277Hz C# 16-3/4"
  A-125-H  (?) A-125-311 311Hz D# 15-11/32"
  A-125-HH (?) A-125-349 349Hz F ? ?
    A-125-440 440Hz A ? ?
  A-200-LL ? ? ? ? ? ? ? ?
A-200-RR (?) A-200-L  A-200-156 156Hz D# 24-29/32"
  A-200-H  A-200-233 233Hz A# 18-11/32"

To add to the confusion, there are some Leslie drawings prior to 1950 that show the A-125s and A-200s did not actually blow the same pitches as listed above. Instead it shows the following frequencies: A-75-H = 488Hz, A-75-L = 326Hz, A-75-LL = 244Hz, A-125-L = 218Hz, A-125-LL = 194Hz, A-200-H = 218Hz, and A-200-L = 145Hz. These drawings also show only two A-125s, not 5 as some have indicated, and two A-200s, and so it's not certain if A-125s smaller than the A-125-L ever existed prior to 1950, or if an A-200-LL ever existed (though it was cataloged in 1947).

a200_030614_1.jpg this rare A-200-233 is owned by Jim Smith
cnj1523_010831_1.wav these last three clips are of restored CNJ GP7 #1523 while in active freight service in 2001
cnj1523_010915_2.wav this engine has twin A-200-156s
cnj1523_010915_5.wav one was recently replaced, whereas the other hasn't been touched in years, creating a "unique" sound
tyfondimensions.jpg dimensions of most of the Tyfon 125 and 200 model horns (courtesy Bruce Feld, used with permission)
dual_a75_gummere_1.jpg very rare dual-tone A-75 with A-75-L and A-75-LL bells (copyright Steve Gummere, used with permission)
dual_a75_gummere_2.jpg very rare dual-tone A-75 with A-75-L and A-75-LL bells (copyright Steve Gummere, used with permission)
dual_a75_gummere_3.jpg very rare dual-tone A-75 with A-75-L and A-75-LL bells (copyright Steve Gummere, used with permission)

Additional Information

Included here are additional general information for the Tyfon line of horns. First, the orifices inside the horns are different depending on the model. A-75s use a 1/8" orifice, whereas A-125s use a 3/16" orifice, and A-200s use a 1/4" orifice. As a result, the air consumption by these "air hogs" are 23 CFM, 50 CFM, and 76 CFM respectively at 100psi (though other diagrams list the A-200 consuming as much as 200 CFM at 100psi, which seems a bit much). As expected, the loudness of these horns increases significantly from model to model. At 100psi, Leslie states the A-75 produces 103db at 100 feet, the A-125 produces 107db, and the A-200 produces 113db! The A-200 may not seem as loud, but that is likely due to the lower pitch of the horn.

As noted prior when describing diaphragm types, the diaphragm material depended in part due to the horn and the pressure at which it would operate. For instance, Leslie catalogued horns with 2-piece metal diaphragms when the operating pressure was between 40psi and 80psi. 3-piece metal diaphragms were used when operating pressures were anywhere from 70psi through 300psi. The A-125 and A-200 also had an option of a plastic diaphragm, later replaced by a rubber-faced plastic diaphragm, supposedly for longer life and less wear. The original plastic diaphragm was rated between 80psi and 150psi, whereas the newer rubber diaphragm was rated from 70psi through 150psi. My understanding is that the standard for A-125s and A-200s by the late 1940s was the plastic - and later the rubber - diaphragm, with the metal diaphragm horns only being ordered when conditions warranted.

In the railroad world, it is widely accepted that by the mid-to-late 1950s, very few, if any, Tyfon horns were being ordered new. The SuperTyfon line was superior and was able to compete properly in a chime horn market where the Chime-Tone line failed (see below). However, the Tyfon horn line was not dead by any measure. Leslie continued to market bronze Tyfons for marine use for years to come. As late as 1969, drawings show that parts were still available for most Tyfon horns. Amazingly, as of 1969, the A-75-440 was still catalogued and available to purchase - for marine use! It is unknown when production finally ceased for each Tyfon line, though.


When AirChime entered the chime horn market in 1949 with its H6 and H5, Leslie was eager to jump on board as well. In 1950, Leslie offered eight chime horns, each built using combinations of their Tyfon series horns, bolted to a common manifold. These were called "Chime-Tone" horns, and could be ordered as a complete horn, or as a kit used to convert an existing "honker". The configurations were achieved by grouping three, four, or five Tyfon horns together in various configurations. Most Chime-Tone Tyfons were based around A-125s of varying pitches. Two examples are the A-125-3E and A-125-5A, a three and five-chime horn consisting of various A-125s. A few models included A-200s as well. The A-125-200-5B consisted of four A-125s and an A-200-156, and the A-125-200-5C had four A-125s and an A-200-233.

While no 5-note Chime-Tone horns were ever sold to railroads, confirmed with some Leslie sales reps who were employed in 1950, there are rumors that one was indeed produced. Its whereabounds is unknown today, probably scrapped. It is also known now that the standard horn mount on most locomotives can't provide sufficient air to properly blow a 5-note Chime-Tone anyway. However, there are photos of Tyfon 2- and 3-chimes in service on several railroads. Erie-Lackawanna supposedly applied three-chime ChimeTones to their 800-series E8s, for example. The B&O also used some of these. For instance, FA1 #806 had an A-125-3. The PRR was also a user of 3-note ChimeTones on some of both their Baldwin and EMD passenger units.

Below are designations of the known Chime-Tone configurations. Not shown is that any of these designations can end in "-A", meaning an "alternate mounting" configuration. Following are some rare drawings provided courtesy Bruce Feld, used with permission. He received these drawings, along with a personalized letter, as a courtesy from Mr. John Leslie before he passed away.

Designation Notes Played Bells Used
A-125-3E B, C#, F A-125-247
A-125-3F C#, F, A A-125-277
A-125-200-3G A#, C#, F A-200-233
A-125-200-3H D#, B, F A-200-156
A-125-4A B, C#, F, A A-125-247
A-125-5A B, C#, D#, F, A A-125-247
A-125-200-5B D#, B, C#, F, A A-200-156
A-125-200-5C A#, C#, D#, F, A A-200-233

chimetonead.jpg a Leslie ad depicting the new Chime-Tone line of horns
tyfon3chime.jpg all four 3-note Chime-Tones and their standard configurations
tyfon45chime.jpg the single 4-note Chime-Tone, and three models of 5-note Chime-Tone
alternatemountings.jpg alternate mounting configurations for each model
mountingflanges.jpg a close-up look at the mounting flanges used in Chime-Tone horns
designations.jpg Leslie's official designation for Tyfon and Chime-Tone horns at the introduction of Chime-Tones
chimetone_841.wav A-125-200-3G from homemade 125 bells and bronze A-200-233 (courtesy Jodie Wells)
mov02420_216.wav A-125-5A from homemade 125 bells and stock A-125-247 (courtesy Jodie Wells)

Last modified Oct 02, 2011
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