Air Horns

markpierce said:

...... A fellow berther told me the liveaboard thought I was "showing off" when making a prolonged signal while approaching the breakwater at the marina's exit/entrance. He said he told her it was a required signal..

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That's another of the "rules" that's commonly ignored by recreational boaters. If I were to use a horn signal when leaving my slip, everyone would think I was just showing off. Anyone sleeping on their boat as I'm leaving about daybreak would think worse.

Fortunately, from my flybridge I can see if anyone is coming or going.

I don't think I've heard these horn signals in transient marinas I've visited either.

Larry M said:

If you want loud and distinct, consider a set of train horns.

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I thought about it, but concluded a horn suitable for a 74-meter boat would be sufficient for an 11-meter boat.

Larry M said:

If you want loud and distinct, consider a set of train horns.

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A couple of the truckers up here put them on there trucks.
They do get a person's attention!!!!!!!!
Ted

Go to the Buell Horns website and you can hear how their different horns sound.
It kind of fun. I scared the bejeebers out of my wife.
Marine - Buell Air Horns

What if you're creeping through dense fog and you hear a train horn in front of you?
I'd be thinking I was about to run aground and why is my GPS so far off.

When going from "the jump" (Venice) into the BigMiss during heavy fog, which is normal this time of year, the procedure is to pull back and listen carefully. When you are sure nothing is coming, announce your intentions on the appropriate vhf channells, asking for any concerned traffic, then, Lay down on all the horn you can muster, then get you a$$ out in the channell. More horn is better. These are the big boys, they normally monitor the radio very well, but sometimes they dont. Ships never respond, but they pay particular attention to horn signals.

kulas44 said:

These are the big boys, they normally monitor the radio very well, but sometimes they dont. Ships never respond, but they pay particular attention to horn signals.

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Therein lies the advantage of AIS. When calling a ship by name on channel 16, I'm 100% at getting a response. That includes 2 ships transiting the Panama City channel when I was just there.

Channel 16 is recorded by the Coast Guard. I have a feeling they know that.

Horns use different frequencies to allow some clue on vessel size.

While fun to contemplate the Kalenberg horn for an air craft carrier might nor be good for your whaler.

FF said:

Horns use different frequencies to allow some clue on vessel size..............

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Is that a rule somewhere or an assumption?

Either way, it's a good argument for installing a horn that people will assume is on a larger vessel. Better they lay off the throttle and look to see your 24' boat than to just ignore your signal.

WesK said:

Is that a rule somewhere or an assumption?

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Rule.

To ensure a wide variety of whistle characteristics, the fundamental frequency of a whistle shall be between the following limits:

(i) 70 - 200 Hz, for a vessel 200 metres or more in length;
(ii) 130 - 350 Hz, for a vessel 75 metres but less than 200 metres in length;
(iii) 250 - 700 Hz, for a vessel less than 75 metres in length.

Northern Spy said:

Rule.

To ensure a wide variety of whistle characteristics, the fundamental frequency of a whistle shall be between the following limits:

(i) 70 - 200 Hz, for a vessel 200 metres or more in length;
(ii) 130 - 350 Hz, for a vessel 75 metres but less than 200 metres in length;
(iii) 250 - 700 Hz, for a vessel less than 75 metres in length.

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I wonder if that's the actual length you are or the length you want to appear to be???

Great! Now I'm going to get a citation for an out of frequency whistle!

Is that length overall, length on deck, or waterline length?

Larry M said:

If you want loud and distinct, consider a set of train horns.

Click to expand...

markpierce said:

I thought about it, but concluded a horn suitable for a 74-meter boat would be sufficient for an 11-meter boat.

Click to expand...

Ted said:

A couple of the truckers up here put them on there trucks.
They do get a person's attention!!!!!!!!
Ted

Click to expand...

Northern Spy said:

Rule.

To ensure a wide variety of whistle characteristics, the fundamental frequency of a whistle shall be between the following limits:

(i) 70 - 200 Hz, for a vessel 200 metres or more in length;
(ii) 130 - 350 Hz, for a vessel 75 metres but less than 200 metres in length;
(iii) 250 - 700 Hz, for a vessel less than 75 metres in length.

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psneeld said:

I wonder if that's the actual length you are or the length you want to appear to be???

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Along the same vein, another option for your consideration (perhaps from the swim platform?):

N4712 said:

What kind of fan is that in the top right of the second picture? We've been looking for some like that, for our ER.

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Don't see any manufacturer's labels on the blower, nor did the boat builder list the engine room blowers in the electrical and mechanical parts list. There are two installed. One blows in from the starboard vent, and one blows out the port vent.

Could be automotive or truck cooling fans. These show up in newer vehicles rather than the belt driven fans.

markpierce said:

Don't see any manufacturer's labels on the blower, nor did the boat builder list the engine room blowers in the electrical and mechanical parts list. There are two installed. One blows in from the starboard vent, and one blows out the port vent.

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Thanks for the info.

One blows in from the starboard vent, and one blows out the port vent.

Far better to have both suck out the heat with a passive intake vent

Pressurizing the engine space could cause exhaust fumes , and the general hot stink of an operating engine enter the passenger spaces.

Ski in NC said:

The air horn with a valve control is nice as you can blow a gentle note, or in case of a knucklehead, a full blast.

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I sure agree with that. That's how I installed mine, just used a little pressure regulator on the airline. The horn specs said it needed 45 lbs minimum pressure if I remember correctly but I crank it down to about 25 for normal use and it still works fine - but when necessary I turn the dial to 60 and can knock leaves off the trees on shore. I don't think I've ever needed that volume though, it's pretty obnoxious, except to signal the start of sailboat races.

For the guys that have a manual lever for the horn...I'm guessing you could still put in some kind of electric solenoid for an auto fog horn?

FF said:

One blows in from the starboard vent, and one blows out the port vent.

Far better to have both suck out the heat with a passive intake vent

Pressurizing the engine space could cause exhaust fumes , and the general hot stink of an operating engine enter the passenger spaces.

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I agree with FF above: your diesel engine(s) is a great air intake fan already...you just need to ensure the intake vent area matches the requirements of your total HP. Engine room fans should be dedicated to exhausting hot air (which will in itself help draw fresh air in). (Again, unless you have chosen to go down the Delta-T slightly pressurized pathway.)

psneeld said:

For the guys that have a manual lever for the horn...I'm guessing you could still put in some kind of electric solenoid for an auto fog horn?

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Yep, just put the solenoid valve in "parallel" with the manual valve, then when either opens, horn blows. A needle valve downstream or upstream of the solenoid valve can be used to control sound level when in fog mode.

I have an electric/manual combination valve.

Electric/Manual Combination Valve V-150AL | Kahlenberg