I have noticed that the horns on the new MP36 engines delivered to MARC in Maryland have a distinctive interurban "whistle" sound. Are these a new design in place of more tradition five-chimes and other air horns? Are they air-supplied as the sound seems to indicate?

Thanks.

Wesley

The MARC MP36 locomotives have an Airchime WH30271 five chime air horn set. They also have a "two intensity" throttling air valve which may be contribute to the whistle-like signature. In addition, they are mounted under the front coupler pocket which can also contribute to somewhat different acoustics due to interaction with the ground profile while moving.

PC

Thanks!