Dual or no dual? Thanks to friend and fellow ship horn enthusiast Jason Bhaskaran, let's find out! The river-class workhorse Manitowoc isn't a common visitor in my neck of the woods, so Jason was kind enough to offer some of his own recordings from the Lake Michigan area for use on this channel. This video would not be possible without him, so I am incredibly thankful for the opportunity to feature the 'Woc and a few more vessels to come! Check out "Jason Bhaskaran Captures" on Facebook for more stellar ship photography and horn videos: profile.php?...
Like all her near-sisters in the distinctive river class, Manitowoc is fitted with a pair of Kahlenberg Arctic S-5 air horns centered atop her pilothouse. Manufactured by Kahlenberg Industries, Inc. of Two Rivers, WI, both units sound at a little over 100 Hz. The Arctic designation indicates that each horn is mounted within a heated box to allow for operation in the frigid Great Lakes winters.
The Manitowoc is a frequent capture for Jason, so this video features two salutes from two different dates. In the first, the Manitowoc sounds only one of her S-5s, while in the second, she lets loose a full dual-horn blast with both units sounding in tandem. If you listen closely, you can audibly tell the difference between the two variations - the single horn sounds with a rather steady pitch, while the dual horn has a periodic "pulsing" as both tones are mixed. This phenomenon is not limited to the S-5 and may be heard from any pair of horns sounding at approximately the same frequency as each other. The physics behind this and other acoustic effects will be discussed in future videos!
A close-up shot of the Manitowoc's pilothouse at 0:17 offers a great look at her twin S-5s, indicated by the arrows in the picture. In fact, the zoomed circles even reveal the printed text on the heated Arctic boxes themselves:
KAHLENBERG
TWO RIVERS, WIS
ARCTIC HORN
MODEL
SERIAL
Intro video by VartanMercadanti, pixabay.com, free license.
Intro audio by kbeezy88, pixabay.com, free license.