1951 Louisville and Nashville Nathan AirChime M5
When I found this horn it was in rough shape, it had a broken #4 power chamber and cracked manifold. I found a replacement power chamber and reused the old button back cap and diaphragm discs.
All of the power chambers are of the "Patent Pending" type, and the #3 chamber is a block back. All of the chambers with exception of the replacement #4 are numbers matching date stamped "D51AY," signifying that this horn was built in April of 1951.
The five power chambers were originally 5/16" inlet, I had Mike choke them down to the proper Swanson specified 3/16". (Note- Nathan Mfg. company bored out the stock 3/16" inlets to make the horns louder and wear out quicker so they could sell more replacement parts.)
The horn is in all original railroad applied paint sans the replacement #4 chamber.
In the video, air is supplied by a 1958 EMD GMD-1, built for Canadian National Railways as CN 1022, rebuilt and renumbered in 1989 to 1415. It was sold around 2014 to Western Rail Inc, a locomotive refurbisher and leaser based in Airway Heights, Washington.
The image carousel to the left shows the progress of photos when I bought the horn to after Mike Muha repaired it.