Air Horns 101

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HopCar said:
I wonder what the logic is to require different frequencies for different size vessels? Do lower frequencies carry further for a given decibel level?
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Lower frequencies might naturally make people think bigger. That's all I can figure.
 
The loudness (sound pressure level) is specified by the IMO, here:

https://kahlenberg.co.uk/imo-requirements/

If your horn (whistle) meets the regs, it should have a certificate from the U.S. Coast Guard, ABS, the British MCA, among others, confirming their compliance with the ’72 COLREGS.

If it doesn't, ask the manufacturer. If the manufacturer cannot provide one, it's likely the horn doesn't meet the regs.
 
greatpapabear said:
The loudness (sound pressure level) is specified by the IMO, here:

https://kahlenberg.co.uk/imo-requirements/

If your horn (whistle) meets the regs, it should have a certificate from the U.S. Coast Guard, ABS, the British MCA, among others, confirming their compliance with the ’72 COLREGS.

If it doesn't, ask the manufacturer. If the manufacturer cannot provide one, it's likely the horn doesn't meet the regs.
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Again, respectively, whether it has a certificate or not, as long as it toots, that's all that matters, at least for recreational boats.
 
I will admit my horns are loud. So if you believe your horns are not up to par, get behind me and you will never have to use your horns.
 
greatpapabear said:
So does federal override IMO?
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Not sure I haven't taken a dive into it. Basically, as far as U.S. recreational boating is concerned a horn is a horn. Can be hard mounted, portable etc,. USCG just wants to know if you have a tooter.
 
Alaskan Sea-Duction said:
Not sure I haven't taken a dive into it. Basically, as far as U.S. recreational boating is concerned a horn is a horn. Can be hard mounted, portable etc,. USCG just wants to know if you have a tooter.
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That starts to make sense. The IMO regs apply to everyone (IMO - International Maritime Organisation), unless you are on inland waterways where a separate jurisdiction may apply. I suspect the federal rules come under that umbrella.

The people to know the absolute fact would be Kahlenberg, since they make horns for the US military as well as commercial and leisure vessels, and distribute them worldwide.
 
OP here, after many years I am still amazed at how a simple post can go all over the subject matter.

I found my horn setup inside the dash/console storage area on the flybridge not in the small compartment over the lower helm. Plenty to room for a couple of small trumpet players if I wanted. Also looked at the horn itself and I don't think I need a new one, just a piece for it. However, I'm not sure what is it called or the best place to buy a new one. Hydraulics supply? It's a hollow threaded rod that attaches to the horn on the exterior, comes up through the deck, and is bolted on the interior to hold the horn in place. The air hose is connected to the end above the bolt. It is 4" long and 3/8" diameter. The opening for the air travel is 1/8". As you can see, the part that was exposed is rusted beyond recognition. The good end, not rusted, went into the horn. See pics. I just need to know what this is called, where to get it.

If someone says "It's called a hollow threaded rod available at Home Depot" I'll feel completely stupid and sell the boat.
 

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Perhaps a hydraulic shop can build one for you?
 
firstbase said:
No idea. I was hoping someone would recognize it. Maybe Hopcar having been in the business....
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I was amazed at the stock of air parts available in the Western Star Truck shop in Kelowna BC, just when I was looking to upgrade the air horns on my first Motorhome. If there is a major brand Truck shop in your vicinity, a visit might reveal the same for you.
 
Our boat came with triple-trumpet Buell horns powered by a CO2 bottle. It is Buell design. They are REALLY loud.
 
Air horns

Firstbase, try searching hollow rods or tubing in lighting or lamp supplies. You may have to put a tubing adapter on it.
 
Thanks for this thread… I’ve had this boat and horn since 2001 and have “needed” to honk it just a few times. It’s a silly sounding honk but it gets the job done well enough.
I’m embarrassed to admit I’ve considered changing it out to a more stout manly sounding MAN horn… Then I come to my senses and realize how silly that would be of me. I laugh at silly people…Not get in line with them. That said, someday it will quit working and I’ll replace it with a horn to blow smaller boats off the water in fear of pending collision and eminent death.
 
Var Korall said:
Firstbase, try searching hollow rods or tubing in lighting or lamp supplies. You may have to put a tubing adapter on it.
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Thanks, I"ve been searching for hollow pipe, hollow tubes, threaded hollow pipe, etc. Haven't found what I need...yet. I got that old fitting with the 1/8" restriction at the end off of the rusted tube and tapped out the threads, nice and clean. Now I just need a 4" long piece of threaded 3/8" tubing/pipe.

I mentioned to someone in a PM that this has turned into a Mission From God. I don't like something getting the best of me (stupid attitude that generally doesn't pay off). If I had used the time I've spent trying to beat it I could have installed a new horn and been 3/4 of the way to Miami on the ICW. Not that anyone in their right mind would go south on the ICW to Miami but...you get my point.
 
I have Fiamm horns and for the first decade I had to strip, clean, and re-tune them each spring. The access is easy - under the circular label at the back of the horn is a screw that priovides access to the innards.

The 12V units have a make-and-break contact that lets current flow through the coil, which breaks the circuit, which reconnects the breaker, etc. The diaphram vibrates accordingly. You can tune them (I have the pair, like many others on TF) and by adjusting the screw tensions you can get them to resonate at a nice pitch each.

To solve the leaking and annual cleaning problem, I made a little Sunbrella bag that goes over the backs, and since then they have gone through every winter without a refurb in the spring.
 
firstbase said:
Nice pic. I'm talking about the ICW down to Miami, the concrete canyon, 1,000 boats, 50% being driven by folks that don't have a clue.
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You can honk your horn…
I’ve been up and down and up and down… Staying in different marinas months on end to enjoy the nice spots to eat and play tennis. I hopscotched a car so I wasn’t stuck with Yacht Dwellers 100% of the time. I would grind miles out offshore to avoid the parade.when it was calm and I wanted fish. The sweet wide open areas south start at Key Biscayne.(pictured). I miss it and the Bahamas.. Now I’m trying to figure out how to enjoy the West Coast and eager to reach Mexican waters. I’ve honked my horn twice in two years.
 
firstbase said:
Nice pic. I'm talking about the ICW down to Miami, the concrete canyon, 1,000 boats, 50% being driven by folks that don't have a clue.
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What you have looks like a sort of custom bulkhead fitting. These type are designed to go through some sort of, well, bulkhead, and deliver air or fluid through the center. The one you have looks like it was designed for hydraulic systems with the heavy wall section and parallel threads. If you do a google image search for hydraulic or pneumatic bulkhead fittings you will see a huge variety and might see something that will fit your need.
 
The distance between mm1075 and the miami outlet is 5 bridges.
The distance between mm1075 and Ft Lauderdale outlet is 5 bridges.
 
Go with kahlenburg. See and hear horns on their website. Great horns.
 
bgillroy said:
Go with kahlenburg. See and hear horns on their website. Great horns.
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For us, a horn comes under the same category as life saving kit. When you need it, you really need it and horns come under the heading of 'no-penny pinching allowed'.

If, perchance, you were in thick, thick fog and can't see more than a few metres (as we have around the UK coast Channel Islands and Coastal France), you'll really want loud - so would your insurance company in case of a claim - which means it needs to meet the IMO regs. Certification by an approved body (such as the U.S. Coast Guard, ABS, etc) is the only way to prove this. Just ask the manufacturer for proof their horns meet IMO regs and see what they say and can give you.

The only exception is if you are in inland waters where local rules may apply, but rest assured that if your horns meet the IMO regs, they'll certainly meet any local rules.
 
I've decided to install a new system, Kahlenberg. Going to move the horn to the side of the boat w/trumpet slightly forward of the flybridge. The old horn blocked my center window from opening as much as I would like. Does anyone know if there is a max distance from the horn that the solenoid can be installed? I would think that a hose distance of 2' vs. 15' wouldn't make any difference but.....thinking again.
 
firstbase said:
I've decided to install a new system, Kahlenberg. Going to move the horn to the side of the boat w/trumpet slightly forward of the flybridge. The old horn blocked my center window from opening as much as I would like. Does anyone know if there is a max distance from the horn that the solenoid can be installed? I would think that a hose distance of 2' vs. 15' wouldn't make any difference but.....thinking again.
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You won't regret it. With regards to the mounting, remember:

  1. Point the horns directly forwards - not angled down.
  2. Keep the distance between the solenoid and the horn as short as possible. That will keep compressed air close to the horn, so when you press the horn button there is minimal delay before the horn sounds.
  3. Since the hors are LOUD, warn and crew in front of the horns you are about the press the button!

Let us know how you get on.
 
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