Diesel Duck
Senior Member
In another thread (now closed) Mark Pierce made the following statement regarding the selection of an air horn for his 35' Coot: "The chart shows minimal tone/range for various vessel lengths. I went one step above the minimum (deeper tone and half-mile range rather than quarter-mile)......." Note: I'm assuming the "chart" he's referring to is the chart shown on Kahlenberg's web site.
Link to previous thread now closed: http://www.trawlerforum.com/forums/s9/kahlenberg-k-380-air-horn-package-essentially-new-18464.html
The reason I'm bringing up this closed thread along with Mark's comment and his ultimate selection of a specific model/style of air horn (a Kahkenberg D2) is because while I was doing some research I came across information that, to my understanding, Mark's choice of air horns was not within the limits of the USCG's regs as described in their Navigation Rules Annex lll.
The rules, as I interpret them, state that a vessel of less than 75m is to have a horn/whistle that produces a frequency between 250-525 Hz. That being said, one of Mark's horns that make up the Kahlenberg D2 (the Kahlenberg D2 has two horns) produces a frequency of 212 Hz.
So my questions are.... Is my interpretation of the regs correct? Can you have too low of a frequency for your horn?
For reference, below is a copy and paste from Annex lll of the USCG Navigation Rules (for International Waters):
"§ 86.03 Limits of fundamental frequencies
To ensure a wide variety of whistle characteristics, the fundamental frequency of a whistle shall be between the following limits:
(a) 70-200 Hz, for a vessel 200 meters or more in length;
(b) 130-350 Hz, for a vessel 75 meters but less than 200 meters in length;
(c) 250-525 Hz, for a vessel less than 75 meters in length."
Link to the USCG Navigation Rules: http://www.navcen.uscg.gov/pdf/navrules/navrules.pdf
Link to the D2 on Kahlenberg's site: Model D-2 Chimetone Air Horn | Kahlenberg
Edited... Added content.
Link to previous thread now closed: http://www.trawlerforum.com/forums/s9/kahlenberg-k-380-air-horn-package-essentially-new-18464.html
The reason I'm bringing up this closed thread along with Mark's comment and his ultimate selection of a specific model/style of air horn (a Kahkenberg D2) is because while I was doing some research I came across information that, to my understanding, Mark's choice of air horns was not within the limits of the USCG's regs as described in their Navigation Rules Annex lll.
The rules, as I interpret them, state that a vessel of less than 75m is to have a horn/whistle that produces a frequency between 250-525 Hz. That being said, one of Mark's horns that make up the Kahlenberg D2 (the Kahlenberg D2 has two horns) produces a frequency of 212 Hz.
So my questions are.... Is my interpretation of the regs correct? Can you have too low of a frequency for your horn?
For reference, below is a copy and paste from Annex lll of the USCG Navigation Rules (for International Waters):
"§ 86.03 Limits of fundamental frequencies
To ensure a wide variety of whistle characteristics, the fundamental frequency of a whistle shall be between the following limits:
(a) 70-200 Hz, for a vessel 200 meters or more in length;
(b) 130-350 Hz, for a vessel 75 meters but less than 200 meters in length;
(c) 250-525 Hz, for a vessel less than 75 meters in length."
Link to the USCG Navigation Rules: http://www.navcen.uscg.gov/pdf/navrules/navrules.pdf
Link to the D2 on Kahlenberg's site: Model D-2 Chimetone Air Horn | Kahlenberg
Edited... Added content.
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