Are flares an anachronism in today's world?

[DaveS]

Re: Are flares an anachronism in today\'s world?

A 50 Hz alternating current reverses its direction of flow then reverses back again every cycle. There are 50 cycles every second. Each cycle contains the instant where the current is at a maximum in one direction, the instant when it is at a maximum in the other direction, and two instants when the current is zero. A light is brightest at each current maximum (regardless of direction) and dark when the current is zero. Therefore in one cycle the light pulses on twice, and in 50 cycles it pulses on 100 times.

 

[sarabande]

Re: Are flares an anachronism in today\'s world?

Thanks for the info, guys; I have just drawn a graph and see exactly what you mean.

Progress !

 

[MichaelHomsany]

Re: Are flares an anachronism in today\'s world?

[ QUOTE ]
Can you cite references

1 for the effects of occulting lights on e.g. epileptic fits, please ? I have an understanding that it's flashing lights which can trigger.

2 for the great perceptibility of occulting lights over flashing lights ? The latter seem to be the norm in the emergency services.

thanks

[/ QUOTE ]
Somewhat like a TV preacher, the research I'm quoting is our own.

I think that the strobing lights on emergency vehicles are a more a function of available technology (strictly opinion!).

On the over-driving. The high intensity LEDs are a bit of a different animal than a 'normal' semi-conductor because it's life is a function of the PN junction heat and the heat effects on the phosphor reflector.

As far as the reflector goes, a perfectly acceptable current drive level to the semi-conductor, has a dramatic effect on the phosphor life. There is a very sharp 'knee' in the lifetime intensity curve between 10 and 20 ma of drive current.

Believe it or not, the reduction in phosphor life between 10 and 20 ma is roughly 3x that of what is seen 20 to 30 ma: In other words, backwards to what 'normal' logic would predict if the situation was purely that of a silicone device. (source on this is unpublished manufacture's data, can't share it due to contracts)

On a Nichia NSPW500, sort level 'v', at 20ma the typical (as opposed to max) output is in the order of 24cd, very close to that of COLREG 4 nm range. Driving at 20ma, the junction is 'safe' and I think (but don't know as of yet) just what the phosphor degradation will actually be.

We do not offer such a product for sale. Again, this is just for the puriently curious.

 

[ColinHuggins]

Re: Are flares an anachronism in today\'s world?

[ QUOTE ]
That old flare may just be the last left you have and save your life.

[/ QUOTE ]

And it may just cause first-degree burns as it turns into a dollop of molten gunge in your hand.

Been there, done that, not nice anywhere, worse in the middle of the Irish Sea.

 

[BrendanS]

Re: Are flares an anachronism in today\'s world?

after the number of threads about wearing leather gauntlets or thick gardening gloves (and keeping them in the flare container) I would hope by now that no one would let of a flare with bare hands

 

[Anonymous]

Re: Are flares an anachronism in today\'s world?

[ QUOTE ]
And it may just cause first-degree burns as it turns into a dollop of molten gunge in your hand.

[/ QUOTE ] That sounds worrying - I had always assumed or believed that when they age they might lose their colour and power but I have never heard that it might be a safety issue. What sort of flare was it and how old?

 

[TheBoatman]

Re: Are flares an anachronism in today\'s world?

Lemain.

The info given below is only my opinion and I have no direct knowledge as to the use of a SART system - so please forgive me if I have got it wrong but I did consult with someone that does use it.

A search and rescue transponder (SART) is a very useful tool to have but they are very rarely fitted to small leisure boats- yes larger ships or SoLas registered boats have to have them, even certain off-shore racing boats are required to carry them but there are some draw-backs to using them.

1. As a piece of rescue equipment they don't "alert" anyone to your distress.
2. The aeriel must be at least 2 mtrs above sea level.
3. From the "rescuers" point of view he gets to see a number of "blips" on his radar screen (12 I believe running away from the target).
4. As the rescue boat closes your position the "blips" start to get closer together and then form into a number of circles.
5. When the rescue boat is within a mile or so, you need to turn off the SART or it will just clutter the radar up so as to make almost unusable.

So for a small boat you need to consider what equipment you "can" carry and how best to help your would be rescuers help you.

Day or night rescues demand slightly different equipment so that has to be taken into consideration - sailing area is important as well -are you sailing close to land, in the middle of the Channel or well offshore?

I go back to my original statement - you need layers of rescue equipment - the more you can provide the better and that IS matched against the boats ability to carry the gear.

My choice as a minimum (not in any particular order) would be a fixed vhf, flares, personal flares to be carried on you, L/raft, PLB, h/held vhf in waterproof bag.

Peter.

 

[ShipsWoofy]

Re: Are flares an anachronism in today\'s world?

When I get rescued I have decided that I will need one h/h smoke and a torch. I have planned everything, how we will blow the dinghy up, when I will make the VHF MAYDAY call, what items I will pack and take into the dinghy. I have even decided what my mayday wardrobe is going to be, slacks and a nice shirt.

Or