Foghorns - usability and effectiveness

James_Calvert said:
I had a gas one once. Only made a decent sound when it wasn't damp....

Now I have a blow-in-a-hole-in-the-side one. You can alter the tone by adding a bit of piping to it; would be interesting to know if that made any difference to its audibility. Gets the noise a little further away from the ear anyway.

Edited: A few different lengths and we could also play at evading the Viper (Peter Duck reference).
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I was once in thick fog on a very cold November morning, hearing a big, big thumping engine approaching. Pressed button on gas foghorn, got a second of loudish noise, then a strangled squawk as the diaphragm froze up. Took a long time for the ice to melt to start working again ..... Not that anyone on a ship's bridge would have heard it.

Now do I run my own very noisy engine and at least have way on to turn if I see a big bow approaching (but no longer hear the ship's engine) or carry on under sail at less than a knot (but hear the approach) ???

When I started to hear a bow wave as well as the thumping engine I started my own engine. Long before the days of cheap VHFs (only rather rich people with big boats had them, and only very rich people indeed had radar) but I did have a radar reflector hoisted. I never saw the ship....
 
I actually had to use sound signals due to fog in the Wallet last Friday. It's a plastic vuvuzela-a-like thing which does seem to make a loud noise. When I started there was another smallish sailing boat about 250 m away and after a while they joined in too. However in the course of the trip I also saw a larger sailing boat, a wind farm boat and a three masted schooner, all under engine, and not one making sound signals. As Rum Run has a BMW D7 I couldn't hear much but certainly would have heard one. I could hear a ship fog horn in the distance but I had about three metres under the keel so felt safe from that. RR seems to show up on radar if I heard the shouted message from the schooner correctly, but it was all a bit disconcerting.
The plastic hooter seems ok. I'm a bit asthmatic so did wonder about running out of breath, but one strong exhale roughly every minute was perfectly sustainable.

Cheers
Rum Run
 
JumbleDuck said:
Coo, that's surprising. I wonder why they don't just say "visibility below xxx metres"?
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I suppose it depends on the effect of poor vis. In local coastal waters with no commercial traffic then 1000metres when sailing at 5knots gives you about 20 minutes of visibilty. In a shipping lane with big boys doing 20knots then 5 minutes of visibilty is definitely "restricted"
 
There must be a simple cheap electronic device from China that allows a switch to be pressed to put a fog horn into operation so the helmsman doesn't need to press a button every x numbers of seconds; signal as required by the vessel being helmed. I can't find one !!!!
 
GrahamHR said:
There must be a simple cheap electronic device from China that allows a switch to be pressed to put a fog horn into operation so the helmsman doesn't need to press a button every x numbers of seconds; signal as required by the vessel being helmed. I can't find one !!!!
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There's FogMate ( http://fogmate.com/HTML/index.htm ), but it's not particularly cheap... could probably build your own with an Arduino or PIC
 
AndyJ76 said:
There's FogMate ( http://fogmate.com/HTML/index.htm ), but it's not particularly cheap... could probably build your own with an Arduino or PIC
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It's also annoyingly fiddly to operate, because they're obsessed with not requiring numpty boatowners to add extra control switches. So it's spliced into the nav light and existing horn circuits, and you tell it what to do by flicking these on and off in various coded patterns.

Personally, I would just want a separate multi-position switch to select OFF / SAIL / POWER / ANCHOR etc.

Pete
 
Monique said:
?

COLREGS were written when? My opinion ... the particular chapter dealing with making noises at sea is past their "best by date" and perhaps even irrelevant in this day and age. (I agree with colregs by the way...)

I prefer being proactive at detecting others than relying on a fog horn to be heard.

Not all regulations are appropriate.
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And your excuse for not complying with the manoeuvring signals?
 
Storyline said:
some people said the type that you fill with a bicycle type pump were difficult to use over a prolonged period.
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Hook it up to one of those cheapo 12v compressors and forget about the hand pump - noisy as hell and lasts a loooonnnnnggggg time :D
 
JumbleDuck said:
As a matter of interest, how reduced does visibility have to be to require sound signals? My google-fu has failed me. I have a red Plastimo mouth blown tooter, by the way, which did pretty well in Sailing Today tests.
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An interesting question. Already partially answered the rule is for reduced visibility just not fog.
Anything less than clear is reduced but when does reduced invoke the requirement for a sound signal.

The generally accepted answer is when the visibility is reduced to less than the range which the sound signal is required to be heard

You will find the equipment for different size of vessels in the Annex 111 B section C.
I think I have copied it correctly.

A whistle fitted in a vessel shall provide, in the direction of maximum intensity of the whistle and at a distance of 1 metre from it, a sound pressure level in at least one 1/3rd-octave band within the range of frequencies 180-700 Hz (+/-1 per cent) of not less than the appropriate figure given in the table below.
Length of vessel in metres 1/3rd-octave band level at 1 metre in dB referred to 2 x 10-5 N/m2 Audibility range in nautical miles

200 or more 143 2
75 but less than 200 138 1.5
20 but less than 75 130 1
Less than 20 120 0.5

So as you can see a VLCC should be sounding if visability is less than 2 miles
My boat is less than 20 so for me 0.5 miles.
 
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For those of you who think your sound signal would be inaudible.

I can hear people talking on shore when sailing in light conditions or out in a canoe. Even though I might be a mile off.

I'm sure many of you have similar experience. Sound caries over water
I live approximately 10 miles from Active Pass. Some days I can hear the Ferry whistles when out on my deck.
Sound carries better in fog.
When I travel on a ferry on a foggy day they always have a lookout on the bow. On the small ones this is the forward end of the car deck. Probably not much fun in the middle of winter.

Although I have never been on the Isle of white Ferry. I would not be surprised if they post a lookout outside when in reduced visibility.

Older ships had bridge wings and bridge wing doors to leave open so they could hear.
The new environmentally sealed bridges are required to have micro phones so the can hear.

In any even its probably other small boats who would benefit from your sound signal.

I don’t generally go sailing if I think it will be foggy. I do carry one of those little air can horns still sealed in its plastic pack. I also have a funny little brass trumpet which is rather like a party favour. It meats my legal requirements.

If I am out in reduced visibility, I can hear ships engines, as well as fog signals. Truthfully I’m not quite compliant. In that I don’t sound every two minutes.

To me the following is a reasonably practical compromise.

I answer any signal I hear just after I hear one. With my trumpet. If I think its big I sacrifice an air horn and replace later.

If I can see 0.5 I am not to uncomfortable with the conditions. I can manoeuvre well within this distance.

My new boat has a RADAR. I could blow my trumpet every time I had a possible target inside 0.5m. I have yet to be out in such conditions. In fact I have not yet had occasion to use the RADAR. Though I have been out without RADAR and GPS. And did as above.

I have considered fitting a hard wired horn. But I just have not found the need come up enough.
 
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GrahamHR said:
There must be a simple cheap electronic device from China that allows a switch to be pressed to put a fog horn into operation so the helmsman doesn't need to press a button every x numbers of seconds; signal as required by the vessel being helmed. I can't find one !!!!
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Yep most commercial vessels have them.
 
GrahamHR said:
There must be a simple cheap electronic device from China that allows a switch to be pressed to put a fog horn into operation so the helmsman doesn't need to press a button every x numbers of seconds; signal as required by the vessel being helmed. I can't find one !!!!
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Lots of vhfs can do it via the loudhalier.
 
JumbleDuck said:
Are the manoeuvring signals supposed to be mandatory? I don't think I have ever heard one. They would make races a bit noisy, wouldn't they?
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I don't believe they are mandatory, but they can be useful.

In Southampton Water a lot of people tend to give way to anything commercial regardless of the rules - in practice this is probably necessary or sometimes the Red Funnel would be practically walled off from Southampton by the flow of yachts out of the Hamble. However, it does create something of a confused situation with smaller commercials like ferries and bunker-barges, where they may be expecting you to give way because most do, but you're both also aware that the rules say you should stand on. If you are in fact standing on, a quick couple of toots and flashes of the manoeuvring light give a reassuring confirmation that they're intending to keep clear without them having to make an exaggerated course change gesture.

I don't think I've ever heard manoeuvring signals from a leisure vessel, and suspect in many or most cases the recipients wouldn't understand them. I know someone on the mobo forum gave two blasts to indicate that they were turning to starboard to avoid a race committee boat in Chichester Harbour, and got a mouthful of abuse for "beeping his horn" at them! And of course, only a very small handful of sailing yachts are equipped to conveniently give sound signals in the first place.

Pete
 
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prv said:
I know someone on the mobo forum gave two blasts to indicate that they were turning to starboard to avoid a race committee boat in Chichester Harbour, and got a mouthful of abuse for "beeping his horn" at them!
Pete
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Perhaps they were confused that he gave two blasts on the horn when turning to starboard, not the single blast the rules dictate.
 
Are manouvering signals required.

The answer is in Rule 34.

RULE 34 - Manoeuvering and warning signals
When vessels are in sight of one another, a power-driven vessel underway, when manoeuvering as authorised or required by these Rules, shall indicate that manoeuvre by the following signals on her whistle:-
One short blast to mean "I am altering my course to starboard";
two short blasts to mean "I am altering my course to port";
three short blasts to mean "I am operating astern propulsion".
Any vessel may supplement the whistle signals prescribed in paragraph (a) of this Rule by light signals, repeated as appropriate, whilst the manoeuvre is being carried out:

For sound signals
When vessels are in sight of one and other. It refers specifically to power driven vessels. And uses the word “shall”
“Shall” leaves no room for options.

Any “May” supliment with a light. May is optional.

So it follows if you are motoring manouvering whistles or sound signals are required. The light is optional.

For other types of vessel “any vessel may” would indicate manouvering signals are optional.

When sailing they are optional.
I can't say I've heard very many MOBO's make one.
I have heard ships make them on a few ocasions but certainly not every ocasion.

It wouldn't even occur to me to sound a manouvering blast on my 16ft runabout when I'm going fishing. It might scare the fish.
 
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