Go Back   Cruiser Log World Cruising & Sailing Forums > Cruising Forums > General Cruising Forum
Cruiser Wiki Click Here to Login

Join Cruiser Log Today

Reply
 
Thread Tools Search this Thread Display Modes
 
Old 05-27-2007, 01:28 PM   #1
Admiral
 
JeanneP's Avatar
 
Join Date: Jul 2004
Posts: 2,098
Default

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.

__________________

__________________
In 1986 we went cruising for a few years. After 20 years and 50+ countries and several oceans, we are STILL "cruising for a few years".

SY WATERMELON |
MV WATERMELON (New) | Cruiser's Dictionary, free ebook

= Cruiser's Dictionary, North America,
JeanneP is offline   Reply With Quote
Old 05-27-2007, 07:08 PM   #2
Ensign
 
Join Date: May 2007
Posts: 20
Send a message via Yahoo to sailman
Default

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.
__________________

__________________
sailman is offline   Reply With Quote
Old 05-27-2007, 07:11 PM   #3
Admiral
 
Nausikaa's Avatar
 
Join Date: Sep 2005
Posts: 1,619
Default

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.

Aye

Stephen

Yacht NAUSIKAA
__________________
Yacht NAUSIKAA | Call Sign: 2AJH2




WHEN WAS THE LAST TIME YOU DID SOMETHING FOR THE FIRST TIME?

www.nausikaa.org.uk

= Sweden, Norway, Denmark, Lithuania
Nausikaa is offline   Reply With Quote
Old 05-27-2007, 07:27 PM   #4
Retired Mod
 
Lighthouse's Avatar
 
Join Date: Mar 2007
Home Port: Durban
Posts: 2,984
Default

Are we talking about boiled eggs here?

__________________


The World Cruising & Sailing Wiki

Help to build this free, online World Cruising Guide.

"Built by cruisers, for cruisers''

I've Contributed to the Cruisers Wiki: Most sections
Lighthouse is offline   Reply With Quote
Old 06-01-2007, 10:52 PM   #5
Ensign
 
Join Date: May 2007
Posts: 19
Default

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
__________________
RobinStorm is offline   Reply With Quote
Old 06-01-2007, 11:00 PM   #6
Admiral
 
Auzzee's Avatar
 
Join Date: Jan 2005
Home Port: Darwin
Vessel Name: Sandettie
Posts: 1,917
Default

"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!

David
__________________
"if at first you don't succeed....Redefine success"!


Auzzee is offline   Reply With Quote
Old 06-01-2007, 11:16 PM   #7
Ensign
 
Join Date: May 2007
Posts: 19
Default

"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?
__________________
RobinStorm is offline   Reply With Quote
Old 06-01-2007, 11:38 PM   #8
Admiral
 
Auzzee's Avatar
 
Join Date: Jan 2005
Home Port: Darwin
Vessel Name: Sandettie
Posts: 1,917
Default

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.

David
__________________
"if at first you don't succeed....Redefine success"!


Auzzee is offline   Reply With Quote
Old 06-02-2007, 12:47 AM   #9
Ensign
 
Join Date: May 2007
Posts: 19
Default

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.
__________________
RobinStorm is offline   Reply With Quote
Old 06-02-2007, 01:19 AM   #10
Admiral
 
JeanneP's Avatar
 
Join Date: Jul 2004
Posts: 2,098
Default

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.

??
__________________
In 1986 we went cruising for a few years. After 20 years and 50+ countries and several oceans, we are STILL "cruising for a few years".

SY WATERMELON |
MV WATERMELON (New) | Cruiser's Dictionary, free ebook

= Cruiser's Dictionary, North America,
JeanneP is offline   Reply With Quote
Old 07-13-2007, 12:18 AM   #11
Ensign
 
Join Date: Dec 2006
Posts: 10
Send a message via MSN to johnnyonspot
Default

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.
__________________
Johnny Neophyte
johnnyonspot is offline   Reply With Quote
Old 01-08-2009, 02:26 PM   #12
Retired Mod
 
Lighthouse's Avatar
 
Join Date: Mar 2007
Home Port: Durban
Posts: 2,984
Default

Well, I would certainly not have the unit where it is.
__________________


The World Cruising & Sailing Wiki

Help to build this free, online World Cruising Guide.

"Built by cruisers, for cruisers''

I've Contributed to the Cruisers Wiki: Most sections
Lighthouse is offline   Reply With Quote
Old 01-14-2009, 09:03 PM   #13
Commander
 
Join Date: Mar 2007
Posts: 129
Default

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. . . . ..
__________________
osirissailing is offline   Reply With Quote
Old 01-15-2009, 09:41 AM   #14
Commander
 
edsailing's Avatar
 
Join Date: Jul 2008
Posts: 120
Default

Ouch!
__________________
Regards

Ed

Delivering boats for a living

+44 (0) 7932039727
edsailing is offline   Reply With Quote
Old 01-29-2009, 03:08 PM   #15
Ensign
 
Join Date: Jun 2008
Posts: 38
Default

To cite Wikipedia on microwave radiation:

Quote:
Microwaves contain insufficient energy to directly chemically change substances by ionization, and so are an example of nonionizing radiation. The word "radiation" refers to the fact that energy can radiate. The term in this context is not to be confused with radioactivity. It has not yet conclusively been shown that microwaves (or other nonionizing electromagnetic radiation) have significant adverse biological effects at low levels. This is separate from the risks associated with very high intensity exposure, which can cause heating and burns like any heat source, and not a unique property of microwaves specifically.

During World War II, it was observed that individuals in the radiation path of radar installations observed clicks and buzzing sounds in response to the microwaves radiation. Microwaves could cause the perception of sounds in the human brain by inducing an electric current in the hearing centers of the brain.
__________________
Yttrill is offline   Reply With Quote
Old 04-16-2009, 09:48 PM   #16
Retired Mod
 
Lighthouse's Avatar
 
Join Date: Mar 2007
Home Port: Durban
Posts: 2,984
Default

I wonder if this guy is still OK.
__________________

__________________


The World Cruising & Sailing Wiki

Help to build this free, online World Cruising Guide.

"Built by cruisers, for cruisers''

I've Contributed to the Cruisers Wiki: Most sections
Lighthouse is offline   Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
New Radar CaptDavi General Cruising Forum 2 06-29-2011 04:14 PM
Broadband Radar MMNETSEA Power & Electronics 1 08-04-2009 12:34 PM
The Sun & UV Radiation MMNETSEA Living Aboard 3 01-30-2009 06:03 AM
Ciguatera, A Danger For Yacht Crews Sailing In The Tropics Auzzee Living Aboard 12 09-16-2007 01:49 PM
Radar reflectors panthablue General Cruising Forum 10 10-16-2005 04:48 PM

Our Communities

Our communities encompass many different hobbies and interests, but each one is built on friendly, intelligent membership.

» More about our Communities

Automotive Communities

Our Automotive communities encompass many different makes and models. From U.S. domestics to European Saloons.

» More about our Automotive Communities

RV & Travel Trailer Communities

Our RV & Travel Trailer sites encompasses virtually all types of Recreational Vehicles, from brand-specific to general RV communities.

» More about our RV Communities

Marine Communities

Our Marine websites focus on Cruising and Sailing Vessels, including forums and the largest cruising Wiki project on the web today.

» More about our Marine Communities


All times are GMT. The time now is 03:03 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
SEO by vBSEO 3.6.0
×