Hope not to cause Controversy but I need a Radar Reflector.

[StellaBorealis]

I would like to hear advice on this topic. Im sure its been discussed before but I am stepping my new (to me) mizzen mast in two weeks time, Along with digging up a new spreader light, new Radome and mount I want to mount a rdar reflector at the spreaders before we step.

I have heard good things about the thing that looks like a big fender on the mast but would be interested to hear what people in this group know?

I figure since my recent channel crossing that many of your UK Sailors might have a particular interest in being seen by commercial freighters (I know I did) and there might even be some people with commercial experience who could provide some insight about what works and what doesnt.

I hate to believe its all so cryptic as it seems.

Thanks to you all in advance,
--
=====
Fair Winds and
Following seas,
Adam Yuret
s/v Stella Borealis
Magellan 36' Ketch
http://www.stellaborealis.com (under construction)

/|\
/ | \ |\
__/__|__\_|_\
~~~~~'----------'~~~~~~~~~~

 

[charles_reed]

Firdell Blipper?

Most of the "tests" that have been carried out suggest all reflectors have disadvantages despite the competing claims made by manufacturers.

On the whole the old-fashioned tetrahedron, properly mounted, seems to be the most adequate all-round performer, especially if you go for a really large one.
The disadvantage is its cumbersomeness and wind-resistance.

 

[Talbot]

Agree with the other reply. The old fashioned rain catcher is a cheap and effective device, especially if you have a second mast to mount it on. I you want a nice fender style one, then the firdell blipper or the echomax are the only ones to consider.

Personnally I have a cheap (and probably fairly ineffective)thin tube one permanently on the mast as lip service to solas requirements, and a proper rain catcher stowed below for use in fog.

 

[boatmike]

I agree with Talbot and Charles. I have in the past been involved in warship building and seen MoD studies on the subject. It's very complex and there is no easy short answer for a small yacht. However, it is clear that for a passive reflector the Firdell Blipper is good but so is the old tetrahedron.
Just an aside note to Talbot. Hoisting 2 at once can cause problems in that one can cancel the other out! It's weird but true. Lose the little sausage thing and fit the other permanently!

 

[charles_reed]

I tried out

the French "tube", providing it's vertical it gives a surprisingly strong echo, but it's highly directional but less so than the Cyclops.

 

[TigaWave]

I was amazed at the distance we were getting good images on radar (I called a couple of tankers/freigters in Biscay in 10m swell and the boat kind of on her side a lot) we had a maxi blip (I think) fender thingy but it was above the forestay on an 18m mast. My conclusion is that height is the key especially when its rough. It was interesting that even in a quiet area for boats and probably lots of clutter they had still picked us up.

 

[charles_reed]

Ouessant Control

Used to regularly pick me up at 35-40nm. Mind you when he was using Ch16 everybody up to the Lizard was deafened by him.

That was with a 3m high tetrahedral mounted in the "catchwater" position.

I suspect your comment about height is valid, but to offset the benefit of greater range one has to allow for the greater movement in a seaway making a more imprecise target. Big ship x-band will usually pick up a yacht in anything but the worst weather (when clutter rather than lack of signal is the problem). The people you have to look out for are blundering yachties (and sleeping watchkeepers) - a far more significant and critical problem than what reflector and where it is mounted.

 

[Planty]

Same subject different question, I have purchased a large, "French Tube" for my 13mtr MoBo however the only real place to fit it up high is virtually next to the Radar Scanner, any advice whethere this will substantially affect the performance of either piece of kit??

Any guidance much appreciated, Paul

 

[dralex]

Definately the Blipper- it has far more radar reflective surfaces and angles on it than things like the simple octohedral and so has a higher chance of giving good reflections at varying angles of heel. We have ours mounted about 3/4 of the way up the mast ie a lot higher than other boats- I'm sure we are very visible- we have had no close calls at all with large boats cross channel in fog. They all passed over a mile away on out radar.

 

[Mirelle]

Re: Ouessant Control

I remember seeing large tetrahedrals made of wire mesh, which seemed like a good idea, but I have not seen such a thing for some years. Was yours one such?

 

[Swagman]

Re: Ouessant Control

I've had the slimmer tube type version (medium sized) before, and whilst reports on reflective ability in the press etc were not good - fellow yachtsmen checking positions in one offshore event last year, all reported good reflections from our yacht.

Maybe should have removed it at the time and asked them to check on how we were being picked up...........my own gut feeling is the yacht and it's aluminium mast does most of the job.

Now with a new yacht have chosen to go for the old fashioned raincatcher - albeit an 18 inch version - which can be hoisted to a spreader point.

As I think added reflectors are at their most valuable when in fog, and equally having ant dshaped device up the mast when sailing is sure to slow the boat, then hoisting a big raincatcher when we hit fog (and usually drop the sails) makes sense to me.

Cheers
JOHN

 

[RPC]

Onpassage.com have covered this topic in quite a bit of detail, see the following link:

http://www.onpassage.com/Safety_Gear/Radar_reflectors/Radar_Reflectors.htm


Hope this helps

Rod

 

[charles_reed]

Re: Ouessant Control

No, a perfectly standard aluminum clip-together one, which has been in use about 12 years.

 

[Mirelle]

Re: Ouessant Control

Sorry; I had misunderstood you; I had thought you were referring to one ten feet across!

 

[jfm]

Planty, fit it inside a grp locker on the flybr. Then you dont have to look at the ugly thing

In general I think they are a waste of time. We have a leisure grade radar, Raymarine open scanner, and we can see everything. Like tiny pot marker buoys etc. We never fail to see even a tiny RIB, let alone a seagoing boat. Ships are supposed to have better radar, so they must be able to see you even without a reflector

 

[srm]

Whatever type of reflector you use make sure it is mounted as far from the mast as possible (unless you have a wooden mast). Metal masts are very good radar reflectors, they just happen to send the signal pinging off away from the scanner thats looking for you, and so create a blind sector. How wide the blind sector is depends on the geometry of mast and reflector. As a rule of thumb a firdel type reflector mounted on the front of the mast will be blind through most or all of your sternlight sector.

One way around this is two reflectors, one mounted in the conventional and inefficient way on the front face of the mast and a second on the stern to cover the blind sector. My stern one is fixed below the radar scanner on its stern mounted pole. Alternatly, one to port and the other to starboard, at different heights on the mast.

If you mount your reflector on the front of a mizzen you will have two blind sectors, a wide one aft and a narrower one ahead where the foremast deflects pulses.

Sean.

 

[charles_reed]

Re: Ouessant Control

It (the boat) is only 31' long.

The reflectors to which you refer arem no doubt, the ones on the buoys marking each end of the TSS.

Apparently they've arrived at that size by a process of elimination, literally, as the buoys got run down and sunk, they made the rflector larger.

How's that for an example of the Theory of Natural Selection in practise.

 

[Piers]

ISO 8729 (the current performance standard for radar reflectors) is in the process of being revised by the International Maritime Organisation (IMO).

Remember there are two types of reflector. Passive, such as the rain catcher, and active, which are electronic and return a strong pulse when a ship's radar is scanning it. Active should always be able to out perform passive, but will cost!

Following practical tests, the existing standard is only met by very few passive reflectors. Almost none will meet the new standards.

The new standard requires a significant improvement in radar cross section at X band (the sort of radars we use) and now for the first time includes performance at S band (typically a big ship's high definition short range radar).

As has been said, the rain catcher is believed to be the best of passive breed, but things will change in the near(ish) future.

 

[john_morris_uk]

Interested in your confidence in your leisure radar. Last week I was involved in a high seas live firing in the med. The ship I was on made a target out of some canvas and packing crates/pallets with various old containers to try and keep the thing floating. All wood and plastic. At a range of 350 metres(!!) neither our S band nor X band commercial radars could 'see' the target. The radars are the latest commercial high quality bits of kit, and I especially looked for the target on them but it was effectively invisible...

I know that not much of our target was sticking out of the water, but I was still surprised. And yes we did retrieve it afterwards to comply with MARPOL.

 

[Piers]

I agree with your comments about confidence in leisure radar...I've used many leisure (and commercial radars) and the moment the sea starts becoming emotional, targets begin to disappear.

I was on the bridge of a Super-Cat last year. The skipper told me that his X and S band radars did not always pick everything up. He gave an example of a 35' yacht he passed only 100 metres to his starboard. Radar hadn't seen it, and neither had any crew - it was foggy. Made him think....and it made me think as well!

Hence, I use an active system.