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Old 05-27-2007, 01:28 PM   #1
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See picture below,

I heard somewhere that you mounted your radar sender so that it didn't send damaging radio waves into your body. Peter said in the Coast Guard they were warned about getting near the sender/receiving unit, but he said that the radar on a big ship was much more powerful than the radar units used on private yachts.

Anyway, if you look at this radar unit, it is sending its signals right into the skipper's crotch when he's on the fly bridge. It seems to me that it's a lousy place to locate the radar even if there were no radiation risk, but if it will harm him, shouldn't somebody have told him by now?

We've never had radar. this is a curiosity question only.

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Old 05-27-2007, 07:08 PM   #2
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Radar radio waves are not good to stand in front of. They are like microwaves and cook from the inside out. Use your imagination of that capt's future.
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Old 05-27-2007, 07:11 PM   #3
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Hi,

Yes, Peter is right. Big ship radars are much more powerful sets and the come with a warning text.....as a rule stating that you should not appraoch closer to an operative antenna than 4 metres or so. Not only is there a radiation risk but there is also the safety aspect of an antenna turning and knocking someone off the mast it is located on.

OK...smaller boats usually have radars with lower output but the issue with radiation is not just the size of the output but the length of time one is exposed to it. As for the boat in the pic., I would not place any bets on the skipper's ability to sire children!!!

As for someone telling the guy - well, radar sets come with the warning text. It is only possible to legislate against stupidity to a certain degree. This guy is certainly in the running for dope-of.the-month award.

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Old 05-27-2007, 07:27 PM   #4
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Are we talking about boiled eggs here?

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Old 06-01-2007, 10:52 PM   #5
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Let me see if I can put this in layman's terms and the answer is complex. First we must understand how radar works. Radar systems are designed to detect the presence, direction, or range or other moving objects. Radar does this by sending pulses of high-frequency electromagnetic fields (EMF) and or "Electromagnetic radiation field or radio frequency (RF) fields". Radar systems usually operate at radio frequencies between 300 megahertz (MHz) and 15 gigahertz (GHz) ranges. The power that radar systems emit varies from a few milliwatts to many kilowatts. It is important to distinguish between perceived and real dangers here. Most pleasure boat radome's operate at a lower power output than a large ships would. There are also a number of factors that reduce a persons exposure to RF generated fields by radar systems, often by a factor of at least 100.

1. Radar systems send electromagnetic waves in pulses and not continuously. Big difference. This makes the average power emitted much lower than the peak pulse power.

2. Radars are directional and the RF energy they generate is contained in beams that are very narrow and resemble the beam of a spotlight. RF levels away from the main beam fall off rapidly. In most cases, these levels are thousands of times lower than in the main beam.

3. Many radars have antennas which are continuously rotating or varying their elevation by a nodding motion, thus constantly changing the direction of the beam.

4. Areas where dangerous human exposure may occur are normally inaccessible to unauthorized personnel.

Yes standing in front or within 4 meters of any devise that transmits a "Electromagnetic radiation field or radio frequency (RF) field" can be dangerous. Now here is the real catch. It does not just depends on the output power and type of wavelengths and frequencies and whether or not its continuous or pulse. But the key factor here is know as the "Time Weighted Average or TWA" of exposure. Meaning how much time does the person in question risk exposure based on a time weighted average of 8 hours at what power output? Most boaters do not stand in front of any type of Electromagnetic radiation field or radio frequency (RF) field designed for pleasure crafts for any length of time that would approach becoming dangerous. I would hope anyway.

Though this guy was not the brightest light bulb in the closet for having his radome mounted where he did. But his danger exposure is very limited and I would worry more about operational distortions and limitations that can plague a unit like this because of where it is mounted.

Though who ever installed the unit does not understand what the meaning of liabilities means....

Hope this helped?

RS
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Old 06-01-2007, 11:00 PM   #6
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"Let me see if I can put this in layman's terms and the answer is complex." RobinStorm.

Let's put it even more readily understandable laymen's terms.

According to the manufacturers of radar units, there is a danger in mounting a unit in such close proximity to an area where people may be gathered...and may be gathered for a considerable time.

It doesn't matter how you paint it, it still comes out coloured dangerous!

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Old 06-01-2007, 11:16 PM   #7
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"According to the manufacturers of radar units, there is a danger in mounting a unit in such close proximity to an area where people may be gathered...and may be gathered for a considerable time."

I love the part about "Considerable time". Eh....just what does that phrase mean? I am not going to argue over something that should be plainly common sense. But the reason why manufactures write this is exactly because they wish to limit their "liability exposure". Now tell that to the guy who installed it and the "Master" of the vessel who is responsible for the safety of his ship. Of course there is not an attorney out there that not find some form of tort hole with this picture. Moreover, if there was this big danger the USCG or someone Coast Guard or "Insurance Company" would jump all over this.

All I am saying here is that it is important to distinguish between what is a perceived danger and what is a real danger and to understand the rationale behind existing international standards and protective measures that we do use today.

My bet is that this guy does not pilot from his flying bridge when his radome is operational nor does he have parties up there when its operational either. I would hope anyway...

By the way, ever see the waring labels on some fishing rods?
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Old 06-01-2007, 11:38 PM   #8
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I contend there would be no such thing as needing to limit liability exposure if there was not the potential for danger. There is a device emitting potentially harmful radiation near a seat which, irrespective of the dilligence of the vessel's master, could be occupied by a child, by a charter group downing a few coldies, or by the family pooch.

You said it well when you invoked the 'common sense' clause. Unfortunately, common sense in some areas may not be all that common; indeed, common sense ceases to be a factor for people who do not know that the slowly turning doo-dad by their feet is emitting radiation.

People who are familiar with radar will limit their exposure. The reason why the warnings are there, I suggest, is that the injudicial placement of a radar antenna can expose people, who do not understand the principals and dangers of radiation exposure.

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Old 06-02-2007, 12:47 AM   #9
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David,

I do agree that there are dangers, and don't get me wrong, but there are limitations involved. As`far as warning labels are concerned and I don't know about Australia but here in the States, thanks to lawyers and in your case barristers, they place warning labels on everything ... and I am not saying that radar does not have exposure dangers, of course it does. All I am saying is understand that danger and its limitations. However, if your going play "Master" of any type of vessel and your going to equip it was advanced navigational equipment such as radar. You sure as hell better know what your doing and what your operating. Otherwise you as the "Master" hold the ultimate liability as well as a moral responsibility for the safety of your passengers, crew and vessel if anything should go wrong. In my book there are no excuses. Just because you can afford a nice play toy does not mean ignorance is acceptable.

Besides if these was this real exposure danger to radar I should look like a cooked chicken by now and I have been near some very powerful transmitters for extended periods of time.
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Old 06-02-2007, 01:19 AM   #10
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When I first asked this question, I referred to a Raymarine Radar manual, which warned that the radar sending unit should be mounted above eye level. The picture is of a Furuno sending unit, so I've looked further.

The first Furuno instsallation manual I read makes no mention of dangers to the operator (Model 1712), but the second one I looked at (Model 1932MK2) had quite a warning -

Radio Frequency Radiation Hazard

The radar scanner emits electromagnetic radio frequency (RF) energy which can be

harmful, particularly to your eyes. Never look directly into the scanner aperture from a

close distance while the radar is in operation or expose yourself to the transmitting

scanner at a close distance.

Distances at which RF radiation levels of 100 and 10 W/m2 exist are given in the table

below.

Note: If the scanner unit is installed at a close distance in front of the wheel house,

your administration may require halt of transmission within a certain sector of scanner

revolution. This is possible Ask your FURUNO representative or dealer to provide

this feature.

MODEL Radiator Distance to Distance to

type 100 W/m2 10 W/m2

point point

1932 MK-2 XN10A Worst case 0.2 m Worst case 3.0 m

1942 MK-2 XN12A Nil Worst case 2.5 m

Clear as mud to me.

Don't you think that it could be a bit less "technical"? Moreover, the average American is arithmetically challenged, and most Americans are metric-challenged.

??
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Old 07-13-2007, 12:18 AM   #11
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We don't know that he uses the flybridge and radar at the same time. Its hard to believe anyone with a brain cell would not realize the potential... ahem, ill effects and satisfy themselves there is no cause for concern.
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Old 01-08-2009, 02:26 PM   #12
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Well, I would certainly not have the unit where it is.
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Old 01-14-2009, 09:03 PM   #13
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Hey, "Darwin's Award" principle will take care of this guy's problem as surely after sufficient exposure he will not able to reproduce more like him. . . . ..
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Old 01-15-2009, 09:41 AM   #14
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Ouch!
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