Nathan Manufacturing, Inc.

Nathan Manufacturing, Inc. is a division of Micro Precision Group which makes Airchime, Ltd. train horns for North America. It is one of two major horn manufacturers in the United States, Leslie Controls, Inc. being the other. Nathan horn manifolds are "stout and solid-looking", while Leslie's are "open and lacy." ^[1]

Products

The K-series Airchime horn is considered "the industry standard" for railroads. It is sold to manufacturers of locomotives and to fleet operators.

A K5LA Horn on top of a Coaster San Diego Cabcar #2310.

• The K-1 single tone horn includes a die-cast aluminum bell and has frequencies ranging from 261 hertz to 660 hertz.

• The K-3L-CDF three-chime assembly includes three die-cast aluminum bells with the same frequency ranges, and they may be reversed. A shield to protect from snow and other debris may be included.^[2] The original K3L was sand-cast, made by Holden Ltd. of Canada.^[3]

• The K5LA five-chime assembly has five bells whose musical chord helps the horn to be heard and lessens complaints. The bells may be reversed^[2] for trains that go backwards and help those working at the back of the train hear the horn on the front. The K5LA is the most popular horn in use today, with a B major 6th chord (D-sharp, F-sharp, G-sharp, B, D-sharp).^[1] Though first used by Chessie System,^[3] it was developed for Amtrak as a variation on the original K horn, and is the standard horn for Amtrak, CSX, Norfolk Southern,^[4] and Illinois Central as well as commuter and passenger trains.^[5]

Nathan also makes P-series and M-series horns for railroads and CS-Series and KJ-series horns, KSV vertical mount horns, steam whistles, heated horn assemblies, electronic pressure regulators, control valves, flange lubricators and glo rod gauges.^[6]

P-series horns also include single tone (P1), three-chime (P3) and five-chime (P5) versions. The bells are sand-cast. Frequency ranges may be from 220 to 554 hertz.^[7] The P-series horns have longer bells and a heavier manifold than the M-series.^[1] The name of the horn is a P followed by the bells that face forward, followed by R if any are reversed, and then the numbers of the reversed bells; a P12345 is a true five-chime horn with all bells facing forward, while P135R24 has bells 2 and 4 reversed.^[8]

History

Robert Swanson started Airchime Ltd., starting out by making custom steam whistles in his British Columbia home. He liked the sound of steam whistles better than the single-chime horns made by Leslie and Westinghouse Air Brake Company. In 1949, he introduced the Hexatone 5 Chime (H5), of which some odd (60) were made according to Robert Eugene Swanson's personal manufacturing/sales records. The Hexatone H5 was only preceded by the Hexatone H6, of which (4), including a cast iron H6 prototype known as the 'Iron Maiden', were only produced and never sold in any quantity to any railroad and were considered experimental. The H-series and N-series, also rare, preceded the M-series manufactured by Nathan in the United States and Airchime Mfg. Co. of Vancouver, B.C., Canada. Airchime Mfg. Co's M3H became the standard 3-chime horn used in Canada. The Holden Co. Ltd. was the Canadian Distributor of Airchime Mfg. Co's locomotive air horns and steam whistles and did not manufacture any horns or whistles, a very common misconception.

Captain Charles Benter, who followed John Philip Sousa as Marine Corps Band conductor, played a role in developing what is called "the most melodic horn in railroading." The five-chime horn Swanson and Bentor came up with became the M-series horn, characterized by "short, fat bells and open manifold." The M3 had three chimes, and the M5 five chimes. Originally, the M5 had an A Major dominant chord (C-sharp, E, G, A, C-sharp).^[1]

In the early 1950s, Swanson introduced the Nathan Truck Horn in T-E and T-5 versions. In 1953, the truck horn was refined for use on locomotives, becoming the P-series. Swanson, whose Airchime never made the horn, sold the rights to Nathan. He never liked the P-series^[9] considering the K-series to be the ultimate horn, with the P (Pre-set pitch) being a cheaper alternative. The P-series did its job, and was easier to repair than the M-series^[8] because each M-series bell had a separate diaphragm, while the P-series horns had the same diaphragm for each bell, a practice Leslie was already using.^[3] M-series horns also needed more frequent maintenance. The P-series was Nathan Mfg. Co's equivalent to the Leslie SuperTyfon.

The first generation P-series bells "used a phosphor-bronze diaphragm disk. Also, the orifice opened up into a fairly wide, oval-shaped hole in the horn's internal chamber." The second generation P-series diaphragm changed to stainless steel, and the opening was round. The changes made little difference in the sound.^[8]

The P3 was used by the first diesel locomotives of Illinois Central and Southern Pacific. The P5 was used for the passenger trains of Illinois Central, Rock Island and Southern Pacific.^[3]

In 1954, the K5H/K3H made their debut, using a D-sharp minor chord (D-sharp, F-sharp, A-sharp) because of Canadian regulations. "H" stood for "high-pitched" because none of the low-pitched bells available were used. Later, "H" referred to high-profile manifold, while L stood for low-profile. The K5H is described as "unresolved" and "haunting".^[5][10] It was used by Norfolk Southern and CSX (some of whose older engines still use it), and by C&NW. Early K-series horns were sand-cast, like the P-series, but later ones would be die-cast.^[3]

In the early 1960s, Nathan introduced the low-profile P3 manifold, replacing a five-chime manifold used previously even though the horn had only three chimes. Southern Railway used this design.

Deane Ellsworth of Amtrak developed the P5a (A for Amtrak) in 1976. While the P5 had an A Major chord, the P5a changed the A to an A-sharp using a shorter bell.^[8] Also used by Amtrak was the P01235, with an "0" bell which was an octave lower than the #4 bell it replaced.^[11]

In 1975, Amtrak asked for a change in the original K-series, with the third bell changed from A-sharp to G-sharp and the fourth from C to B. The K5LA designation included a "K" for the double-diaphragm kettle drum design, an "L" because of its low-profile manifold, and an "A" for American tuning, to differentiate it from Canadian tuning. By the later 1980s, the K5LA was North America's most popular locomotive horn.^[5]

In 1977, Nathan had two other foundries cast P bells, but new castings were used that did not have the right pitches. The 1, 2 and 3 bells had a slightly higher pitch, and the 5 bell a lower pitch. The result was D, F, G-sharp, A, C, not considered a chord. These horns are considered the third generation P series.^[8]

In 2005, Federal Railroad Administration regulations specified a maximum decibel level for horns, resulting in the development of the K5LLA (the extra "L" means low-pitched, with the first bell tuned to middle C) for EMD and K5HL for GE.^[5]

References

External Links

• Company Website