Boats' Automated Fog Signals

Boats' automated fog signals

Piers wrote:

... *I'm in the middle of ordering a set of D-2 having upgrtaded the air tanks and compressors this last season. Not sure what the benefit is over the D-1 ...

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The D-2 has a deeper/lower tone than the D-1, which is proper because your boat is bigger than mine.* I didn't want people looking for the ferry when it is just little-old me.

*


-- Edited by markpierce on Saturday 18th of December 2010 02:55:35 AM

RE: Boats' automated fog signals

markpierce wrote:"I'm curious as to what extent you folks have automated systems for sounding fog signals....* I'd rather once*push a button or two for the systematic sounding of the horn so to focus on piloting the boat. "
HornBlaster Home Page

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RE: Boats' automated fog signals

There was heavy fog*around 11:00 a.m. today*at the Mare Island Strait entrance.* GPS/chart plotter and radar made it easy to stay in channel and avoid hitting the breakwater, and my fog horns got some exercise.* When returning at* 12:15 p.m. the entrance was clear but heavy fog remained along the Rodeo side as pictured below.

RE: Boats' automated fog signals

SeaHorse II wrote:markpierce wrote:"I'm curious as to what extent you folks have automated systems for sounding fog signals....* I'd rather once*push a button or two for the systematic sounding of the horn so to focus on piloting the boat. "
HornBlaster Home Page

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*

*I have used the HornBlaster for a couple of years.* It works as advertised.* Which is to say, it is a great help to have the fog signal on automatic.

What makes my application a little different, is that I have it connected to a secondary "echo" whistle, a single small trumpet that produces a higher tone.

In my early towing days, tug operators developed great skill in using the echo whistle to help determine close quarters position.* A short pop on the echo whistle and with an ear out the window, you could hear the echo off a building/dolphin/breakwater/vessel, etc.* If there was distinction in the echo, you could*determinal general direction as well.

Mostly, it's a skill no longer used, although every now and then, I will hear someone using occasional short blasts to help in "ranging" as they get close to something.

RE: Boats' automated fog signals

We have a problem brewing the UK with regard to the IMO compliancy of fog horns. In other words, do they meet the COLREGS requirements of boats over 12m?

Three UK leisure boat manufacturers are now fitting IMO compliant horns. Two because they look so much better (!) and one because they realised they may be legally complicit if there was an accident and the horns were not compliant.

To be compliant, the horn manufacturer must be able to supply a certificate of compliancy from an authorised testing lab, such as ABS. In the UK, most horns fitted to leisure boats are small electric horns which do not have the necessary certificates. Most UK loud hailer horns are not compliant.

Realisation of this has recently prompted a UK insurance company to state that a boat is not 'fully' covered if there's an accident and the horns are found not to be compliant.

Interesting times....

RE: Boats' automated fog signals

<h1>Per*Kahlenberg:</h1><h1>IMO Requirements</h1>
<strong class="dblue">What are the international requirements for marine horns (ship's whistles)?[/b]

The 1972 Intemational Regulations for Preventing Collisions at Sea ('72 COLREGS), ANNEX III, entered into force by the International Maritime Organization (IMO), specifies the technical requirements for sound signal appliances on marine vessels. Frequency range and minimum decibel level output is specified for each class of ship. The class is determined by the vessel's length. Sound pressure level intensity at a distance of one meter from the horn is stipulated, which determines the theoretical range of the horn, although the actual range will, under many conditions, be much greater than this. This information is displayed in the following table:


<table style="width:400px;" border="1" cellspacing="0" cellpadding="0"><tbody><tr bgcolor="#2266a7"><td align="center" valign="middle"><strong class="white">Whistle Class[/b]</td><td align="center" valign="middle"><strong class="white">Length of Vessel in Meters[/b]</td><td align="center" valign="middle"><strong class="white">Limits of Fundamental Frequency[/b]</td><td align="center" valign="middle"><strong class="white">Minimum Sound Pressure Level Measured in 1/3 Octave Band at 1 Meter[/b]</td><td align="center" valign="middle"><strong class="white">Audibility Range in Nautical Miles[/b]</td></tr><tr><td align="center">I</td><td align="center">> 200</td><td align="center">70-200 Hz</td><td align="center">143 dB</td><td align="center">2</td></tr><tr><td align="center">II</td><td align="center">75 -200</td><td align="center">130-350 Hz</td><td align="center">138 dB</td><td align="center">1.5</td></tr><tr><td align="center">III</td><td align="center">20 - 75</td><td align="center">250-700 Hz</td><td align="center">130 dB</td><td align="center">1</td></tr><tr><td align="center">IV</td><td align="center">< 20</td><td align="center">250-700 Hz</td><td align="center">120 dB</td><td align="center">0.5</td></tr></tbody></table>
*
The range of audibility in the table above is for information and is approximately the range at which a whistle may be heard on its forward axis with 90 per cent probability in conditions of still air on board a vessel having average background noise level at the listening posts (taken to be 68 dB in the octave band centred on 250 Hz and 63 dB in the octave band centred on 500 Hz).

In practice the range at which a whistle may be heard is extremely variable and depends critically on weather conditions; the values given can be regarded as typical but under conditions of strong wind or high ambient noise level at the listening post the range may be much reduced.

<strong class="dblue">Certificates of Conformity[/b]

Certificates for Kahlenberg Horns have been issued by the U.S. Coast Guard, ABS, and the British MCA, among others, confirming their compliance with the '72 COLREGS.

<strong class="dblue">Installation[/b]

When a directional whistle is to be used as the only whistle on a vessel, it shall be installed with its maximum intensity directed straight ahead.

A whistle shall be placed as high as practicable on a vessel, in order to reduce interception of the emitted sound by obstructions and also to minimize hearing damage risk to personnel. The sound pressure level of the vessel's own signal at listening posts shall not exceed 110dB (A) and so far as practicable should not exceed 100 dB (A).

Fitting of more than one whistle:

If whistles are fitted at a distance apart of more than 100 metres, it shall be so arranged that they are not sounded simultaneously .

Combined whistle systems:

If due to the presence of obstructions the sound field of a single whistle or one of the whistles referred to in paragraph 1(f) above is likely to have a zone of greatly reduced signal level, it is recommended that a combined whistle system be fitted so as to overcome this reduction. For the purposes of the Rules a combined whistle system is to be regarded as a single whistle. The whistles of a combined system shall be located at a distance apart of not more than 100 metres and arranged to be sounded simultaneously. The frequency of any one whistle shall differ from those of the others by at least 10 Hz.

Bell or Gong Requirements

(a) Intensity of signal

A bell or gong, or other device having similar sound characteristics shall produce a sound pressure level of not less than 110 dB at a distance of 1 metre from it.

(b) Construction

Bells and gongs shall be made of corrosion-resistant material and designed to give a clear tone. The diameter of the mouth of the bell shall be not less than 300 mm for vessels of 20 metres or more in length, and shall be not less than 200 mm for vessels of 12 metres or more, but of less than 20 meters in length. Where practicable, a power-driven bell striker is recommended to ensure constant force but manual operation shall be possible. The mass of the striker shall be not less than 3 per cent of the mass of the bell.

3. Approval

The construction of sound signal appliances, their performance and their installation on board the vessel shall be to the satisfaction of the appropriate authority of the State whose flag the vessel is entitled to fly.

RE: Boats' automated fog signals

Piers wrote:
To be compliant, the horn manufacturer must be able to supply a certificate of compliancy from an authorised testing lab, such as ABS.

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Just for the record, the American Bureau of Shipping (ABS) is a class society and not a laboratory.

It is the responsibility of the manufacturer of an item required by statute to meet certain performance standards to use one of many approved laboratories to document that product's performance. The certification process is quite complex and involves inspection of the manufacturer's process and facilities as well as materials and sources.

The USCG has an equipment approval program that is very similar and also requires the use of an independent USCG approved testing laboratory. The USCG and/or IMO define the standards, the labs determine if the product meets those standards by using standardized and consistent testing methods and documenting the process.

Because ABS is a member of the International Association of Class Societies (IACS) an approval certificate issued by ABS or any other member such as Lloyds or DNV is considered by national maritime authorities as equivalent and is accepted as complying with national and international standards.

RE: Boats' automated fog signals

I installed a Fogmate and use it frequently in the CA Delta. I like that is requires no switches or control panels and is operated by use of the nav lights and horn button.

To activate, turn on the nav lights and then immediately depress the horn button. The horn beeps to acknowledge the system is on, then enters into the sounding cycle. There are different modes for power/sail and underway/at anchor. To turn the Fog Mate off, turn off the nav lights. Simple, inexpensive and effective.

RE: Boats' automated fog signals

RickB wrote:Just for the record, the American Bureau of Shipping (ABS) is a class society and not a laboratory.
It is the responsibility of the manufacturer of an item required by statute to meet certain performance standards to use one of many approved laboratories to document that product's performance. The certification process is quite complex and involves inspection of the manufacturer's process and facilities as well as materials and sources.

The USCG has an equipment approval program that is very similar and also requires the use of an independent USCG approved testing laboratory. The USCG and/or IMO define the standards, the labs determine if the product meets those standards by using standardized and consistent testing methods and documenting the process.

Because ABS is a member of the International Association of Class Societies (IACS) an approval certificate issued by ABS or any other member such as Lloyds or DNV is considered by national maritime authorities as equivalent and is accepted as complying with national and international standards.

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Thanks for this, Rick. Perfect. Also just seen your profile - impressive!