Leslie Tyfon air horns were some of the first air horns to appear on railroads, dating back as far as about 1934. 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, 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.
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 not common, 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 have heard of dual A-125s and A-125/A-200 combinations that 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!
While very rare to see, these combinations did exist.
| 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 | |
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| a200_weiler_1.wav | an A-200-156 in active service (Copyright Norman Weiler, used with permission) |
designations
By about 1950, 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.
A-200-156-PA
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).
Next you have another number, which is the frequency or pitch of the horn in hertz, so 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 (one, two, and three leaf bronze diaphragms were all possible).
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).
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 around 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. 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.
| 1930s-era Classification |
1940s-era Classification |
1950s-era Classification |
Pitch (in Hertz) |
Note Played |
| A-75-LL | A-75-262 | 262Hz | C | |
| A-75-M RR (?) | A-75-L | A-75-330 | 330Hz | E |
| A-75-H RR (?) | A-75-H | A-75-440 | 440Hz | A |
| A-125-M RR | A-125-LL | A-125-206 | 206Hz | G# |
| A-125-H RR | A-125-L | A-125-247 | 247Hz | B |
| A-125-M (?) | A-125-277 | 277Hz | C# | |
| A-125-H (?) | A-125-311 | 311Hz | D# | |
| 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# |
| A-200-H | A-200-233 | 233Hz | A# |
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 | |
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| cnj1523_010831_1.wav | these last three clips are of restored CNJ GP7 #1523 while in active freight service in 2001 | |
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| cnj1523_010915_2.wav | this engine has twin A-200-156s | |
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| 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) |
Chime-Tone
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 using their Tyfon series horns.
These were called "Chime-Tone", 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.
No 5-note Chime-Tone horns were ever produced (only blue-printed). This was confirmed with some Leslie sales reps who were employed in 1950. But there are a few photos of Tyfon 2- and 3-chimes in service. Erie-Lackawanna supposedly applied three-chime ChimeTones to their 800-series E8s. 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.
| Designation | Notes Played | Bells Used |
| A-125-3E | B, C#, F | A-125-247 A-125-277 A-125-349 |
| A-125-3F | C#, F, A | A-125-277 A-125-349 A-125-440 |
| A-125-200-3G | A#, C#, F | A-200-233 A-125-277 A-125-349 |
| A-125-200-3H | D#, B, F | A-200-156 A-125-247 A-125-349 |
| A-125-4A | B, C#, F, A | A-125-247 A-125-277 A-125-349 A-125-440 |
| A-125-5A | B, C#, D#, F, A | A-125-247 A-125-277 A-125-311 A-125-349 A-125-440 |
| A-125-200-5B | D#, B, C#, F, A | A-200-156 A-125-247 A-125-277 A-125-349 A-125-440 |
| A-125-200-5C | A#, C#, D#, F, A | A-200-233 A-125-277 A-125-311 A-125-349 A-125-440 |
| 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 |
last updated 10/13/09