Prime Train Horns History
Prime Manufacturing has the status of a recognized company that manufactures engine accessories and other locomotive parts for quite a long time now. It has established a name for itself in the rail road business for so many years now, crafting pneumatic bell rings, air conditioning units, cab mirrors, and even locomotive air horns, among others. Yes, for almost thirty years, beginning in 1972, Prime has produced locomotive air horns. During that time, the air horn business was booming, and Primecapitalized much on that, producing and selling basically two models of horns, the PM920 and the PM990, but offering other types as well.
The most common train horn developed by Prime was the PM920. This train horn had a manifold with a low profile with 1, 2, and 4 bells. The PM920 used to play a C, a D#, and an A, the same triad played by the S-3L of Leslie. However, with the advent of new castings also came new sounds. Later, PM920 horns were able to produce a B, a D#, and a G#. During this time, there were horns playing the chord B, D#, and A, the same chords being sounded by Leslie's S-3L horn. Other horns around this time sounded the G# major triad, playing a C, a D#, and a G#.
The PM990, on the other hand, might not be as common as the PM920, but it was nevertheless popular during that period. This horn used bells 2, 3, and 5, and sounded a D#, an F#, and an A#. The PM990 was a hit to the Burlington Northern, a railroad company.
Prime also offered other types of horns, only that they were very rare and not as well known as the PM920 and the PM990. These other types of horns were the PM927, PM928, and PM 929. The PM927 was a horn that could play only a single note, much like Leslie's S-25, S-31, and so on. The PM928, meanwhile, had bells 2 and 4, and was similar to Leslie's S-2M. This horn was extremely rare, with only one believed to remain these days.
The last of the horns offered by Prime was the PM929. The PM929 used bells 1, 2, 3, 4, and 6 on a 5-chime manifold, which was more or less the same manifold used by the SL-4TX of Leslie. The PM929 horn was a copycat of Leslie's S-5T. Sadly, though, the PM929 did not make it to the market as Prime did not have any orders for this kind of horn, so this type of horn, together with the 5-chime manifold and bell 6, was never produced at all.
In 1999, after being in it for some 27 years, Prime finally let go of the horn business, leaving a considerable number of stocks and spare parts. These remaining stocks of horns were sold to a private horn collector. When Prime gave up the horn business, it also destroyed nearly all its documentations of the horns, articles, and similar records; thus, with no record available, it became quite difficult to trace the history of the horns. Fortunately, some concerned collectors took pains in trying to piece together any information available regarding these horns. Fortunately, too, two large customers of the Prime horns, the Union Pacific and the Burlington Northern, are still existing to this day, and they still have many of the horns in their possession.
The horns manufactured by Prime were similar to Leslie's S-Style SuperTyfon series. Mechanically, they were so similar that their parts could even be used interchangeably with one another. For instance, a Leslie S-style diaphragm could be used on a Prime horn in case the Prime diaphragm was not available. Some railroads, too, used Leslie's RS-style power chambers with their Prime horns to extend their service life. However, this was as far as the similarities between them went. Their physical attributes were very much different from one another. For one, the horns manufactured by Prime were heavier. This was because the parts of the Prime horn were mostly made of aluminum, thus naturally, their casting was heavier. Also, the tones produced by Prime and Leslie horns were different. Prime horns were able to produce a smoother, richer tone than Leslie horns. This, accordingly, was a result of the heavier casting of Prime horns.
Another distinct feature of Prime horns was the presence of a support rib on each side of the bells. The support rib ultimately gave the bells a sturdier appearance. The bells, too, showed the part number, as well as the date on their sides. Moreover, the base of the Prime bell was round, whereas, in the Leslie horn, the base of the bell was somewhat scalloped. A part number cast could be seen on the back of the Prime horn's power chambers. The front of the power chambers was round with six half-circle cut-outs. In contrast, the base of the power chambers of the Leslie horns was narrow; neither was it round. Another difference between them could be seen in their manifolds. The manifold of a Prime horn had its name on it, while the same was absent on a Leslie horn.
Another area that differentiated Prime from its other competitors came in the number of accessories it offered for its horns. One such accessory seen during the 1980s, was a set of pressure-triggered valves located inside the manifold of the horn. These valves, however, were utilized by low profile three-chime manifolds only. They were positioned in the air passage, specifically between the middle bell and the outside bell. The rationale behind this was to enable the engineer in an urban setting to pull the whistle cord halfway while keeping the air stream from reaching the outer bells. In a rural setting, however, the engineer could be able to pull the whistle cord all the way, allowing maximum pressure to enter the manifold. This would open the internal valves, enabling the horn to sound all three bells. These manifolds were not among Prime's initial offerings; in fact, they were introduced only in 1973 after the first change involving bell casting was made.
Apart from this manifold feature, another offering Prime had was the riser. The riser served to lift up the horn by some three inches off the mount, allowing low profile horns to have extra clearance, while still providing enough support. These risers were not very popular, though.
Over the period of some thirty years, several arrangements were offered by Prime. Various changes were made, from chords to bell castings. Such changes resulted to the production of two different notes for two of Prime's bells. The first change happened very early on, in 1973, to be exact, a year after Prime started venturing into the horn business, while the second change happened much later, sometime during the 1980s. Prime changed the bases of its 1 and 4 bells, making them flat instead of round.
Prime is now being owned by the Dayton-Phoenix Group, Inc., but it continues to manufacture many products.
