Amtrak's F40PH Horn Relocation
|When Amtrak's F40PH's were first
delivered, the airhorns sat in the notch in the cab roof just above the numberboards.
On locomotives 200-229, this notch was just wide enough to hold the Nathan P-5a. Later
F40's had a wider notch to accomodate the K5LA.|
Mounting the airhorn on the cab roof provides the greatest volume and sharpness of sound, but it also raises the noise level in the cab. To reduce the cab noise on the already noisy F40PH, Amtrak began relocating the horns as shown in the photo at left in the early 1990's. The new location gets the horn away from the cab, but the position immediately behind the exhaust stack is less than ideal for the horn. The ill effects of heat and exhaust start to take their toll on the horns' sound often within a few months.