Mollari
Well-Known Member
Shame I wasn't born a century earlier, I could have saved the Titanic.
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Masthead Strobes
- Thread starter MainlySteam
- Start date
MainlySteam
Well-Known Member
Thanks for the responses.
Can assure everyone that the strobe is not used for navigation - in fact it has never been used at sea, ever, and is only occasionally tested in the marina (when everyone ducks thinking it is a low flying aircraft).
We got it purely for identification and assistance in location in a crisis eg during a rescue search. I think I would also use it in a panic collision avoidance situation in that the switch is always to hand whereas hand lamps and flares may not be and may also take time to initiate. The anti collision thing (the "steamer scarer") came to mind the other day and is what prompted my post.
I was in the wheelhouse of a power vessel with eye level being approx 8.5 m above the waterline and doing around 35 knots. It was showery but with reasonable visibility - just that greyness everywhere. We sighted a target ahead on the radar but none of us (around 7 people in wheelhouse at the time) could see it until it was very close (in fact surprisingly close) and only became visible when its mast (turned out to be a yacht around 30 foot) rose well above the horizon so that it was contrasted against the misty cloud rather than the sea (he did not have his nav lights on, and should have - we did).
I am not suggesting that a strobe should be used by a yacht in those circumstances as nav lights would have been his correct procedure. Did remind me how hard it can be to see a yacht from a bigger vessel and made me think of the strobe (in a panic situation).
Have always meant to connect it to both the intruder alarm and the bilge alarm but have never gotten around to that bit /forums/images/icons/frown.gif.
John
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Can assure everyone that the strobe is not used for navigation - in fact it has never been used at sea, ever, and is only occasionally tested in the marina (when everyone ducks thinking it is a low flying aircraft).
We got it purely for identification and assistance in location in a crisis eg during a rescue search. I think I would also use it in a panic collision avoidance situation in that the switch is always to hand whereas hand lamps and flares may not be and may also take time to initiate. The anti collision thing (the "steamer scarer") came to mind the other day and is what prompted my post.
I was in the wheelhouse of a power vessel with eye level being approx 8.5 m above the waterline and doing around 35 knots. It was showery but with reasonable visibility - just that greyness everywhere. We sighted a target ahead on the radar but none of us (around 7 people in wheelhouse at the time) could see it until it was very close (in fact surprisingly close) and only became visible when its mast (turned out to be a yacht around 30 foot) rose well above the horizon so that it was contrasted against the misty cloud rather than the sea (he did not have his nav lights on, and should have - we did).
I am not suggesting that a strobe should be used by a yacht in those circumstances as nav lights would have been his correct procedure. Did remind me how hard it can be to see a yacht from a bigger vessel and made me think of the strobe (in a panic situation).
Have always meant to connect it to both the intruder alarm and the bilge alarm but have never gotten around to that bit /forums/images/icons/frown.gif.
John
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qsiv
Well-Known Member
We have one - though strobe isnt really the term, as it is an LED. It's primary purpose is to iluminate the underside of the windex - the fact that it isnt too bright aids night vision. The secondary purpose (for us) is to aid identification when returning to the boat in a crowded anchorage.
In neither instance is it used as a navigation light, nor is it likely to be confused with one, as it is not visible at long distances.
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In neither instance is it used as a navigation light, nor is it likely to be confused with one, as it is not visible at long distances.
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Ruffles
Well-Known Member
Unfortunately though strobe lights appear very bright at close quarters they dissappear at distances of a mile or so. I imagine it is something to do with the very short duration and the graininess or periferal vision.
I used to sail with a guy who worked in medical avionics (!). Apparently the raf spent millions on them as part of their emergency kit and then had to replace them.
I was always told to shine a light into the mainsail to show your position. Always wondered what it looked like from the bridge of a ship though.
Rob.
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I used to sail with a guy who worked in medical avionics (!). Apparently the raf spent millions on them as part of their emergency kit and then had to replace them.
I was always told to shine a light into the mainsail to show your position. Always wondered what it looked like from the bridge of a ship though.
Rob.
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MainlySteam
Well-Known Member
Must be the atmosphere up there in the northern hemisphere /forums/images/icons/smile.gif - I have seen white strobes from many miles away no problem at all at night.
Perhaps one reason why they put them on aircraft on which I have seen them from probably 10 - 20 miles away at night, including on military aircraft (and also in the northern hemisphere).
Perhaps you are talking about little hand held sized ones?
John
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Perhaps one reason why they put them on aircraft on which I have seen them from probably 10 - 20 miles away at night, including on military aircraft (and also in the northern hemisphere).
Perhaps you are talking about little hand held sized ones?
John
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Bodach na mara
Well-Known Member
The aviation industry started switch to strobes about 60 years ago. There is a passage in E K Gann's book "Fate is the hunter" that describes the opposition from the controlling authorities, who said they were "illegal". The view of the pilots was that was better to have a bright flashing but illegal strobe seen than a legal fixed light not noticed. Time the law was changed for marine use as well.
<hr width=100% size=1>Ken Johnson
<hr width=100% size=1>Ken Johnson
Peppermint
Well-Known Member
Re: Top book
Gann is one of my all time favorite writers. Bit of a sailor man too.
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Gann is one of my all time favorite writers. Bit of a sailor man too.
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Oldhand
Well-Known Member
The streamer I was referring to is a 2.5" tube, filled with kerosene and arrays of hydrophones, towed 5 to 10m under the surface. Doesn't scare anyone until they rap it round there bow or propeller
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peterb
Well-Known Member
A few years ago Trinity House put an experimental buoy fitted with a xenon flash light on to their test ground off Harwich. We found that it was very easy to see, but almost impossible to get a bearing from. The flashing rate was quite slow (5 sec?). If you pointed a hand bearing compass towards it then it was most unlikely to be dead on bearing when the light flashed, and without some sort of continuing light it was difficult to correct. I wonder whether a strobe light might have the same effect; easy to see but difficult to tell whether it was on a steady bearing.
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boatless
Well-Known Member
I nearly sailed an Oyster 39 smack bang into a then new North Sea LANBY. Had seen the bright flashing for miles, next thing I know it was about 20 feet up in the air, just next to the spreaders. Distance off is hard to gauge.
<hr width=100% size=1>my opinion is complete rubbish, probably.
<hr width=100% size=1>my opinion is complete rubbish, probably.
MainlySteam
Well-Known Member
I have done that with a conventional flashing light on a pile too /forums/images/icons/blush.gif.
John
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John
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MainlySteam
Well-Known Member
As flash rate and visibility has come up I have checked what ours is rated at - the Aqua Signal 40 strobe in a masthead strobe/tricolour/anchor light unit is 60 flashes/minute and rated at 3nm visibility - do not know about figures for others that may be available.
John
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John
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Ruffles
Well-Known Member
It seems my information was, like me, a tad out of date:
"Strobe lights. There are several concerns over the use and effectiveness of xenon discharge strobe lights in this role. They vary from considerations of their effectiveness in waves and in their very short duration, to others about the safety of survivors on whom they operate. Many of these were found by the authors of the HSE publication (OTH 93 407) to be specious. In spite of the effects of those which had any truth in them they considered that, subject to incorporation of a longer pulse (say 0.1 to 0.2 seconds) and an increase in the flash rate from 50/60 per minute to 75/150 per minute, they offer the most effective light base method of detecting and locating a person or persons lost at sea at night."
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"Strobe lights. There are several concerns over the use and effectiveness of xenon discharge strobe lights in this role. They vary from considerations of their effectiveness in waves and in their very short duration, to others about the safety of survivors on whom they operate. Many of these were found by the authors of the HSE publication (OTH 93 407) to be specious. In spite of the effects of those which had any truth in them they considered that, subject to incorporation of a longer pulse (say 0.1 to 0.2 seconds) and an increase in the flash rate from 50/60 per minute to 75/150 per minute, they offer the most effective light base method of detecting and locating a person or persons lost at sea at night."
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AndrewB
Well-Known Member
Strobes tend to be used by very high-speed craft like hovercraft - and some very racy yachts. My reaction on seeing one at sea is that it is a vessel that will be moving too fast for me to respond to, so it can be expected to take the initiative in keeping clear, and so long as I'm sure I'm visible I do not alter course to avoid it.
Hope that is the message that you are intending to convey!
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Hope that is the message that you are intending to convey!
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Twister_Ken
Well-Known Member
Bizarre but...
...I have the distinct impression that Masthead Strobes was a Shakespearian actor in the late 1950s.
Matron, more gin with my tonic!
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...I have the distinct impression that Masthead Strobes was a Shakespearian actor in the late 1950s.
Matron, more gin with my tonic!
<hr width=100% size=1><A target="_blank" HREF=http://www.writeforweb.com/twister1>Let's Twist Again</A>
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