The History of Nathan P5 Air Horns

Four main companies made air horns: Nathan, Westinghouse, Leslie and Prime.

Air horns that loudly warn of a train coming down the track have gone through changes over the years. Among the various air horns produced, the Nathan P5 has been one of the most well-liked.

Introduction

The Airchime P series air horn replaced the M series in the 1950's because of the high maintenance that was necessary on the M series. The bells on a Nathan P5 don't need to be tuned and don't wear because they don't have metal-to-metal contact. While the M series bells are short and wide, the P5 bells are long and narrow.

Notes

The P5 originally was tuned to play C#, E, G, A and C# octave, according to TrainWeb. The P5A was developed afterward to play A# instead of A and was used on Amtrak's Turboliners and other trains. Another P5 plays a low A instead of A and was used on Amtrak's E60 locomotives. A 1953 version has bells numbered 0, 1, 3, 4 and 5 instead of the usual 1, 2, 3, 4 and 5 bells.

New Castings

New castings used since the mid-1970's caused most of the bells to play different notes and changed the sound of the P5 from melodic to slightly distorted, says Brent Lee of Soundtraxx. The No. 4 bell is the only one to play its original note. The notes the Nathan P5 now plays are: D, F, G#, A and C. The flare of the bells also changed slightly.

References

• TrainWeb: The "P" Horn
• SoundTraxx: Diesel Locomotive Airhorn History