Radar reflector

[mick]

Do I need one if I have AIS fitted.

[Chris]

Unless you fit an active one they are a waste of time IMO. I think the Aframe would give a better return..

[SPR]

yes - under Solas V if practical you should have radar reflector.....

Echomax make good active and passive reflectors -

http://www.eesc.org.uk/content/club-...eflectors.html

a few reports can be found there...

[Poly]

Originally Posted by discomick

Do I need one if I have AIS fitted.

SOLAS requires all vessels to carry a radar reflector wherever practical, it makes no "exemption" for vessels fitted with AIS transponders.

Only vessels with AIS receivers fitted will see you. Small craft (including fishing vessels, yachts, other, ribs etc) may not have a receiver fitted (or being properly used) but MAY have a radar fitted - they will expect you to have a radar reflector fitted.

There is at least a theoretical risk in busy waters that you don't show up on AIS due to the "clutter" from other users hogging the spectrum.

If you have an electrical failure AIS will not transmit. A passive radar reflector will.

[kerny]

Originally Posted by discomick

Do I need one if I have AIS fitted.

Stick behind Pikey and you'll be reight.

[Poly]

Originally Posted by Chris

Unless you fit an active one they are a waste of time IMO. I think the Aframe would give a better return..

Whilst some radar reflectors are better than others - I think its reasonable to say that a typical a-frame is just about the worst design possible for a reflector. cylindrical surfaces reflect the radar signal away from the source. Features smaller than the wavelength of the radar will be near invisible to radar. X band radar will be very close to that limit for most A-frames. S band will be even more likely to "miss" it. The best radar reflectors would have a cross section of around 10 m2 (although probably only in "ideal" conditions). Your A-frame probably has a cross section of less than 0.3 m - and most of that is pointing the wrong way at any time.

[Chris]

Originally Posted by Polwart

Whilst some radar reflectors are better than others - I think its reasonable to say that a typical a-frame is just about the worst design possible for a reflector. cylindrical surfaces reflect the radar signal away from the source. Features smaller than the wavelength of the radar will be near invisible to radar. X band radar will be very close to that limit for most A-frames. S band will be even more likely to "miss" it. The best radar reflectors would have a cross section of around 10 m2 (although probably only in "ideal" conditions). Your A-frame probably has a cross section of less than 0.3 m - and most of that is pointing the wrong way at any time.

Granted, still probably better than most of the low end radar reflectors floating around. Especially the way people tend to mount them on ribs which is to tie fix them to an Aframe upright or across the top.

[MikeCC]

Do a search for the Qinetiq report on radar reflectors. There may be more than one - I think most recent is the one following the Ouzo tragedy, possibly included in MAIB report.

Essentially for passive type only the Echomax and Tri-Lens are worth having.

The slim tube types are just decoration (bit like those dangly things hanging off car bumpers that were once popular - what were they for?) Only worth installing to keep interested scrutineers happy.

[mick]

How about this



Don't want to end up like this

[Poly]

Originally Posted by MikeCC

Do a search for the Qinetiq report on radar reflectors...
Essentially for passive type only the Echomax and Tri-Lens are worth having.

Mmm... I do wonder whether that report has done more harm than good. Do people just not bother with anything? Whilst the poor ones fall below ISO standards by a long way they must still be better than nothing. The tilt angle problems are much worse on yachts than ribs too, so I am not sure dismissing the traditional (cheap but a little ugly) reflector is sensible.

Has anyone found a practical solution without an a frame?

[Razorbill RIBs]

Originally Posted by discomick

How about this

Attachment 65141

Don't want to end up like this


Attachment 65142

As mentioned the Qinetic report makes interesting reading (although been a while since i read it, so don't take this as gospel, but....)

The Echomax as per your pic did well IIRC (used by lots on here / Atlantic class LB), but if space /size is a concern have a look at the TriLens reflectors, they performed the best from my recollection. Much more compact /smaller (we have a cyclops type on Razorbill)....seem to recall there being some issues with quality of mountings on some models, but that later ones had rectified the issue..........If you search for TriLens you'll find lots of info....

[m chappelow]

even the engine block or a carrier bag filled with squashed up empty drinks cans or baking foil hung from the A frame will give out a better return that some of the cheaper reflectors ,lab tested /coast guard approved or other wise .

[Silverfox]

So these are no good, even if mounted as shown on top of the A-frame?

[m chappelow]

Originally Posted by Silverfox

So these are no good, even if mounted as shown on top of the A-frame?

Attachment 65144

Better than nothing ,
we had this at our boat club when they first came out and some members did our own live tests using most types of leisure boats and a radars mounted on the pilot cutter, lifeboat and local commercial fishing boats ,
look at most proper reviews and tests and some come out very low ,
in a lab test in the vertical position they will show up and will pass most overseas coastguard tests and approvals ,but its when tested at various different angles when you get the big nulls, in reality the same type of angles that a rolling or pitching boat may produce .

have a look at the links
How to choose a Radar Reflector

http://www.hotribs.com/Library/Radar_Reflectors.pdf

[Pikey Dave]

Originally Posted by Silverfox

So these are no good, even if mounted as shown on top of the A-frame?

Waste of space

[Silverfox]

Seems the tri-lens is the one, but it does need to be fitted with a bracket top and bottom, which is ok on a yacht but tricky on an A-frame.

[C2 RIBS]

Originally Posted by Silverfox

Seems the tri-lens is the one, but it does need to be fitted with a bracket top and bottom, which is ok on a yacht but tricky on an A-frame.

Three ways we have fitted tri- lens

The easiest I guess is shown where we just use the base of the NAV White and then feed wire up to nav white above, you just need tri lens two fiitings, they only supply one in the box, that is white ring top and botom on left image.The second image is with an extension piece and raised the white Nav and the third was a stainless box made up with the white screw you see on second image holding the lens to box through a drilled hole.
Hope this helps

[BruceB]

I like mine, a lot better than the crappy "tube" types I used to have..........

[mister p]

One would imagine then, that a radar reflector mounted from it's top and hanging from the A-frame like a lantern ( maybe with a weight attached "pendulum" stylee ), would present it's reflector flanks correctly. Esp for yachty types who are at an angle when under way.

[mister p]

Even if it's swinging it would "flash" for the receiver, as it were.