Last reviewed May 6, 2026
Reviews — Brand Hub

Nathan AirChime Train Horns

The dominant US locomotive horn brand — Nathan AirChime supplies 90%+ of North American locomotive horns. K-series and P-series, 3- and 5-chime, the standard you hear at every freight crossing.

By Train Horn Editorial Published April 28, 2026
Locomotive front close-up — Nathan AirChime supplies the chord-horn assembly on 90%+ of US locomotives

About Nathan AirChime

Nathan AirChime is the dominant manufacturer of locomotive horns in North America, supplying 90%+ of US Class I freight and passenger locomotive horns per the company's own market data. The brand traces back to Nathan Manufacturing (founded 1916, NYC) which entered the locomotive horn business in the 1950s. Today Nathan AirChime operates as a specialty manufacturer focused on heavy-duty industrial and rail horn applications.

Every modern North American Class I freight locomotive (BNSF, Union Pacific, CSX, Norfolk Southern, CN, CP) and most modern passenger locomotives (Amtrak, Metra, NJ Transit, Metrolink, Sounder, MARC) carry a Nathan AirChime horn. The most common model is the K5LA — see our K5LA sound page.

Nathan models (5-chime)

  • Nathan K5LA — modern 5-chime standard. B major 6th chord (D♯/F♯/G♯/B/D♯). The horn you hear on every BNSF / UP / CSX freight today. ~$1,650 horn-only, ~$5,000 complete kit.
  • Nathan K5 — K5LA predecessor with slightly different note voicing. Mostly retired but still on legacy SD40-2 power.
  • Nathan P5 — Penn Central / Conrail-era 5-chime, prized for low fundamental and warm tone. Recommissioned units occasionally appear on surplus markets.
  • Nathan K5H / K5HL — variants with different chord voicing. Less common.

Nathan models (3-chime)

  • Nathan K3LA — modern 3-chime, subset of K5LA chord. Used on switchers and shorter passenger units. ~$1,950 standalone (HornBlasters).
  • Nathan P3 — older 3-chime predecessor, warmer voicing. Common on yard switchers and legacy freight.

Why Nathan dominates the market

  • FRA compliance. All Nathan AirChime models meet 49 CFR § 222 (96–110 dB at 100 ft) without modification. Manufacturer specifies output to the regulatory standard.
  • Cast aluminum bells. Aluminum is stiffer than steel relative to weight — better acoustic coupling, higher peak SPL per material weight.
  • Standardized chord. The K5LA's B major 6th (D♯/F♯/G♯/B/D♯) is now the de facto US locomotive sound. Railfans, sound designers, and aftermarket buyers all reference Nathan as the standard.
  • Long warranty. Nathan AirChime offers extended product support — re-tuning and bell replacement available on most models for decades.
  • Service network. Major rail operators have direct Nathan AirChime relationships. Aftermarket buyers go through specialty distributors (HornBlasters, Train Horn Depot, etc.).
Analog SPL gauge — measuring the K5LA's 149 dB at the source

Where to buy real Nathan AirChime horns

Nathan AirChime sells to railroads and OEMs directly. Consumer / aftermarket buyers go through:

  • HornBlasters — sells real Nathan K5LA horn-only at ~$1,650 and complete kits at $5,000+ (hornblasters.com)
  • Train Horn Depot — specialty distributor
  • Railroad surplus markets — recommissioned units from retired locomotives ($400–$1,200)
  • eBay — used / recommissioned units; verify authenticity carefully

Most aftermarket consumers don't buy real Nathan units. Instead they buy K5LA-style replicas from companies like HornBlasters at ~$1,500–$2,200 for a complete kit — significantly cheaper than a real Nathan and 90%+ as loud (147.7 dB vs Nathan's 149 dB).

Real Nathan vs. K5LA-style replicas

FeatureReal Nathan K5LAK5LA-style replica (HornBlasters Shocker XL)
Output149 dB at source147.7 dB at 3 ft
Bell materialCast aluminumFiberglass-reinforced ABS
ChordB major 6th, factory-tuned4-note approximation
Price (kit)$5,000+$1,800–$2,200
WarrantyManufacturer-direct, decadesLifetime horn (HornBlasters)
AuthenticityReal locomotive hornLook-alike with similar chord

Other Nathan products

  • Industrial signal horns — non-rail applications: ships, ferries, plant whistles
  • Rail air supply / accessories — diaphragms, bell replacements, tuning hardware
  • Custom rail horn applications — heritage / preserved locomotives, museum units
Ear muffs — required PPE around 149 dB cast aluminum locomotive horns at close range

Related pages

Sources