Hoisting octahedral radar reflector

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Gazza

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I've been looking at the best way to hoist a good size (approx 16" across) octahedral radar reflector up to the spreader, using the existing flag halyard and block. Tried it this morning and found that it wouldn't sit in the "catch-rain" position, although given the likely movement of the boat that probably isn't a major problem.

The main difficulty I can see is that of chafe on the lines. With a continuous flag halyard and tying to the top and bottom (with shackles, so no chafe problem there), the fall of the halyard will chafe against the edge of the reflector.

I've tried hauling it up the backstay, using the topping lift, but this wasn't very successful.

How do other people manage with the traditional type reflector which I would only deploy on passage or in poor vis.?

Any ideas/experiences gratefully received.
 
On my previous boat I hoisted it on a spreader flag halyard which was then led via a block on the spreader to mast fitting, then down the outside of the mast. Worked perfectly.
 
I hoisted mine on the spreader flag halyard but, in addition, from the lower connection I had two tethers going out, one to a lower shroud, one to a cap shroud. They were of the right length so that when fully hoisted these tethers held the reflector cocked over to the catch rain position, and also stopped it swinging excessively. The tethers were about 4mm line with bowlines around the shrouds so they slid up the shrouds freely.
 
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I hoisted mine on the spreader flag halyard but, in addition, from the lower connection I had two tethers going out, one to a lower shroud, one to a cap shroud. They were of the right length so that when fully hoisted these tethers held the reflector cocked over to the catch rain position, and also stopped it swinging excessively. The tethers were about 4mm line with bowlines around the shrouds so they slid up the shrouds freely.

[/ QUOTE ]What happened when you changed tacks? Did the reflector cease to remain in the catch-rain position, or were the tethers long enough to let it swing over?
 
It's a bit optimistic to expect the reflector to stay in the catchwater position at all times - it's position is constantly changing as the boat moves around. But this method does restrain the movement to a large extent.
 
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but it is a requirement of SOLAS

[/ QUOTE ] Quite! My point really was that other types faired better in the tests.

Must confess I have an octahedral type mounted permanently between twin backstays. Been there since 1979!
 
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but it is a requirement of SOLAS

[/ QUOTE ] Quite! My point really was that other types faired better in the tests...

[/ QUOTE ]
Except that SOLAS only specify a "radar reflector", they don't specify a minimum standard.
 
Have you got radar?
I hoist my octahedral in raincatch mode up under the scanner where it 'docks' against the scanstrut.
needs a bit of chassis-bashing and thought but it's stable and clear of sails/halliards etc.
 
Bearing in mind that ALL passive radar reflectors were damned in the recent QuinitiQ report www.ybw.com/pbo/pdfs/radar_reflectors.pdf ,

I hang mine below the cockpit radar arch with a shockcord, restraining it in the catchwater position.

As IMHO ships are as likely to run you down in good as well as poor visibility and because of the fag of putting it up and down mine is (semi) permanently rigged.

Mind you, I used regularly be picked up by Ushant control when crossing the TSS between 10-18nm out. However that was a military-trained operator using both X and Y bands, with a considerable LoS elevation and given warning.

All of course, whistling in the dark (but it makes you feel better)
 
My Octo RR has holes and lanyards fitted in long sides to specifically make it hang in the 'rain-catcher' position. My previous boat had similar with its octo RR. Simple matter of a drill and make it so yourself if not already done.

Second to reduce chafe on the halyard line - a small piece of plastic pipe split, then tied with small cord to a hole on the side that has halyard rubbing against. You slip halyard into that and then bit of insulating tape to close the pipe around halyard. Hoist up and bingo ... done.

As to the Report often pointed to in Ouzo Report moment anyone brings up any question regardless of what type reflector .... IMHO any addition to a radar signature no matter how small is appreciated.
The old fashioned octo may be not best, but lots of buoys around the world have them fitted. Seame's are fine but cost money and are at this time limited to one radar type.

I've also quoted on here about experiences where asking bridge watchkeepers as to how far off they 'saw' my boat ( a 25ft motor sailer with no doghouse....) reply has been at good distance well before need to act. Yes it's usually reasonable weather, but if the weather is bad - then you can forget all additions to your boat active and passive - as you are not going to be seen anyway. Remember whatever the unit - it relies on actually being 'hit' by the radar signal and of the signal having clear path BACK to origin.

Just a thought to bear in mind .... /forums/images/graemlins/wink.gif
 
The active Sea-Me at £500 did OK and the passive PolarRef at £2000 was by far the best of the passives. The rest were either next to useless or useless.

The Quinetiq report is certainly an eye opener, but you'd have though the industry would be busting a gut to produce a better product that is affordable. There is a big enough market out there surely.

A Sea-Me is probably not practical on my little boat with only a 80ah leisure battery and solar panel, but I don't know its consumption. For anyone with two batteries and an engine generator I'd have thought the Sea Me was a no brainer really.

Has anyone picked up any industry reaction to this report which is nearly two years old now, or did they just go away and sulk after revelations they had been selling us what, in the main seems to be fairly useless junk if your boat heels at all /forums/images/graemlins/tongue.gif

Tim
 
Sea-me power:

Current consumption in quiescent state 150mA
Current consumption when transmitting 350mA

but it does only transmit on X band as said above, though I think they have plans for S band this year.
 
There are 2 active transponders on the market, using between 80-100milli-amps when "resting" and going up to about 400milli-amps when transmitting.

What you have to be aware is that in an area where they're being continually painted by X bands around them, they'll be in transmit mode most of the time.

As to reaction, yes a second one has been released on the market and the hype about lens-reflectors toned down a lot.

However, if I was a manufacturer of a passive device (especially the French "corners-in-a-tube") I'd be concerned about being reported to Trading Standards, for gross misrepresentation.

The aluminum mast on most boats is probably as good a target as most reflectors.

Best passive target of all would be an aluminised kite of say, 30m2. Just think what fun it would be flying that, crossing the Channel at night in a F7!!!
 
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[ QUOTE ]
but it is a requirement of SOLAS

[/ QUOTE ] Quite! My point really was that other types faired better in the tests...

[/ QUOTE ]
Except that SOLAS only specify a "radar reflector", they don't specify a minimum standard.

[/ QUOTE ]

In fact, if you look back at tests before the QuieticQ the octahedral IF BIG ENOUGH has come out as a "best" all-rounder. It's certainly the best value-for-money.

And, of course, your active target is only as good as the office-of-the-watch, his eyes, his attention, his training and the state of the magnetron.

Just look through the MAIB reports on radar-induced collisions!!!
 
The tests carried out by PBO in 1998/9 and reported in the Jan, April, July & Aug 1999 editions of the magazine make interesting reading.
 
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Best passive target of all would be an aluminised kite of say, 30m2. Just think what fun it would be flying that, crossing the Channel at night in a F7!!!

[/ QUOTE ]

Gor Blimey !! that's same sq.m area as my full sail up. But anyway in that sort of weather you'd be lucky to be picked up on radar whatever radar item you had fitted to your boat ...

What people tend to ignore or maybe do not appreciate. To paint or respond - the signal is not just a single instance. It has to be a multiple respond signal. Radars do not paint sufficiently a target on PPI if a single return occurs unless it's major enough. It requires a multiple return for most items particularly smaller to do so. So I don't give much hope to any passive or active item to paint a return on a Radar in bad weather - where you are up and down serious waves / swell / troughs interrupting line of 'sight' return.
 
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