Radar location on cutter

[Cadence]

If I where young I would have one of the new pulse radars on a taiga. Having to get a sail around one on the mast sucks. JMHO

[On The Water]

Originally Posted by deblen

Some things to consider when locating a radar antenna.
The Dropbox link should contain 3 PDF docs(copies of a generic radar inst manual) & a blurb (Off.doc) by me after 30+ yrs in the business.
Hope the link works.
Hope it helps someone.

Cheers/ Len

https://www.dropbox.com/sh/bdp7snawf...2aRokB8ma?dl=0

I don't want to go against a professional but on your doc.

1.Accept that your primary area of concern is the area directly ahead & to the sides-aft as far as possible.

Having during the last 10 years done multiple yearly passages at a low 10 knot speed in some of the worlds most congested waterways with tight shipping lanes and fog a norm i would differ on above and say under 10 knots the unrestricted radar view should be directly astern be it in the open waters shipping lanes, radar controlled rivers etc. When your speed hits the average speed in the lanes or faster, then forward 100%

4.The radar antenna should be located at least 2 ft above your eye level,to minimize eye damage.

I would not approach or step on a boat (small ship) with radar less than 5 feet above aye level without assurance the radar is off and as skipper would make it clear that if any operations on deck are necessary on such a low radar boat the radar needs to be turned on standby while crew members work on deck (and that is not for eye damage).

[Jim Cate]

Originally Posted by Cadence

If I where young I would have one of the new pulse radars on a taiga. Having to get a sail around one on the mast sucks. JMHO

Have you actually done this, Cadence? I have, for many years, and it is simply a non-event... the sail just goes on by.

Other posters report similar experiences...

Jim

[a64pilot]

If B&G can be believed the RF emissions from their 4G Radar is less than a cell phone, and I put one of those on the side of my head.

EB, if you move your steaming / deck light, move it into the trash, replace it with one from Marine Beam, while I agree saving power on a steaming light is irrelevant, the brighter light and much better deck light that it is, is worth it.


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[Mike OReilly]

Wow. Thanks folks. Hope this thread is an assist to others as well. Lots of great info and experience. I'm going to try a lower install based on all the wisdom here. It makes the cable runs a lot easier as well.

I may have to move my steaming light though... oh well, I need a new one anyway.

[Argyle38]

Add me to the list of folks that have mounted the radar 'under' the inner-forestay attachment point. I had the same thoughts as you, higher and clear of the staysail, or lower.

I ultimately chose lower since I was more interested in using the radar for short range low visibility uses. I mounted the radar right at the spreaders which is several feet below the inner forestay attachment. At this height, the sail has enough flex in it so that it just slides across during a tack. It rubs a little during a tack but there has never been an issue. I had my sailmaker put on a chafe guard at that location on the sail.

[On The Water]

Originally Posted by a64pilot

If B&G can be believed the RF emissions from their 4G Radar is less than a cell phone, and I put one of those on the side of my head.

Radars are cool and I would be hard pressed to go anywhere without one.
Just saying, have a good radar, mount the antenna high.

Plenty of safety concerns if they are not installed and used properly.

Sailors don't have enough electricity to use them to harm, some cruisers might, small commercial boat operators might be killing themselves with them.


Of the few professional (not talking about boatyard or local Furuno van installers) but people who install and service land and ship based marine radars, whom I at times ferry to remote islands to get them to a radar antenna, when you get to know them and have a few hours or so to talk about maybe some exposure related things, you learn to respect the radar.

Lipid peroxidation dosent ask for general public exposure limits.

At points above or below the scanner's horizontal plane, the radiation level is lower than that measured at a corresponding point on that plane. However, it must be noted that the average radar has a rather large vertical beam width (20 to 25 degrees) and microwave radiation is beamed about 10 to 12 degrees above and below the horizontal plane. At 5 feet from the scanner and 1-1/2 foot below the scanner, the average intensity can still be in excess of the OSHA safety limit.

Cell phones, pfft, gave my phone away, wanna call me, try calling someone random, might be next to me.

[elandra65]

Hi Mike,

I have had several boats with the radar mounted just above the first spreader on a two spreader rig. The sweep of the headsail has never been a problem. Other than the time I lost the radome and the bracket damaged the leech but that is another story. Make sure you have a very strong mount though!


regards


Andrew

[ErBrown]

Originally Posted by a64pilot

EB, if you move your steaming / deck light, move it into the trash, replace it with one from Marine Beam, while I agree saving power on a steaming light is irrelevant, the brighter light and much better deck light that it is, is worth it.

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Probably not a bad idea if we're removing the old light anyway.

Besides, once you're hemorrhaging cash, what's a few more bucks...

[Snowpetrel]

Just a random thought, any of you had issues with a radar mounted near the spreaders with backskatter and indirect echos bouncing of the front of the spreader? Might be best to mount the radar a couple of feet above, or below a spreader, then again maybe its not an issue...

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[Jim Cate]

Originally Posted by Snowpetrel

Just a random thought, any of you had issues with a radar mounted near the spreaders with backskatter and indirect echos bouncing of the front of the spreader? Might be best to mount the radar a couple of feet above, or below a spreader, then again maybe its not an issue...

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Ben, IMO it is always better to not add the extra holes and mass loading at a highly stressed spot like near the spreaders. Normally there are already holes (or welding) associated with the spreader bases as well as the tangs or t-ball sockets for the intermediate shrouds and possibly a stay as well. Plenty of stress risers there already... why add more?

And if one had the spreaders right in the plane of the beam, there would be some attenuation of the signal. Don't think that backscatter would be an issue due to time delays, though. At any rate, there are certainly reasons to keep the dome a couple of feet or so away from the spreader locations.

Cheers,

Jim

[Snowpetrel]

True Jim, I wasnt even thinking of the extra holes. If I remember correctly the least stressed part of the mast is around 1/4 of the span towards the spreaders?

On the scattering. The normal result would be more false echos and extra interferance and clutter in the area that the spreaders would partially block, and also reflect some signal forwards.

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[deblen]

Originally Posted by On The Water

I don't want to go against a professional but on your doc.

1.Accept that your primary area of concern is the area directly ahead & to the sides-aft as far as possible.

Having during the last 10 years done multiple yearly passages at a low 10 knot speed in some of the worlds most congested waterways with tight shipping lanes and fog a norm i would differ on above and say under 10 knots the unrestricted radar view should be directly astern be it in the open waters shipping lanes, radar controlled rivers etc. When your speed hits the average speed in the lanes or faster, then forward 100%

4.The radar antenna should be located at least 2 ft above your eye level,to minimize eye damage.

I would not approach or step on a boat (small ship) with radar less than 5 feet above aye level without assurance the radar is off and as skipper would make it clear that if any operations on deck are necessary on such a low radar boat the radar needs to be turned on standby while crew members work on deck (and that is not for eye damage).

Thanks for your reply & confirmation that my link works.

Every situation is different. I have seen radars placed on each end of a commercial vessel for reasons similar to yours. My experience,which included substantial use of radar ,beyond just installing/maintaining them, led me to believe in my point # 2,but you are the user in your situation & are best equipped to decide what works for you.
Eye/body damage from radar refers to <10KW pulse radar in the X band,as would be used on a yacht. I definitely agree that extra precautions such as you state are wise around higher powered X band , S band & commercial/military radar.
I quoted accepted knowledge/experience in my minimum recommendations. There is no harm in you being extra cautious.

Cheers/ Len

[On The Water]

I am probably just over cautious listening to old wife tales on the danger of radar. Probably the new yacht radars are safe at a touching distance, probably the radar crew VTS radars scared me for nothing, but i must say, none of them want any extra radiation and that has rubbed down on to me, no one works on deck with a low installed radar antenna and I definitely shy away from them.

I do a lot of (did) deliveries of old whatnots from Europe North to who knows where they ended pilot, coast guard, patrol scrap, ex soviet included, nothing is a disturbing as a radar with a even moderate blind spot, you just cant trust them, looking at the screen when one cant even see the bow of the boat, trying to trust a device that dosent show all, yeah zig zag and that, when its crowded you cant do that, well you can but the Germans are the first on the horn, was is das, was was and then the....

[Dockhead]

Originally Posted by Paul Elliott

VALIS is a cutter, and our radar is mounted on the mast above the first spreader but way below the inner forestay. We have a substantial stainless ring around the radar support structure, and we've had no problems with the staysail or halyards getting tangled in the radar. Here are a couple of photos with some details:

My radar is set up just like that, except no guard. No problems of any kind, ever.

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