How long from Falmouth to Plymouth

Angele said:
But, at least it stops the gooseneck disintegrating as the boom smacks over to the other side - probably beheading one or two crew members as it goes. :eek:
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It might or might not. In ideal circumstances it will hold long enough that the problem goes away, or even better will slow the boom as it goes accross the boat (there are braking devices on the market for this).

Sadly physics is not on your side here if you have a sailboat since it's pointy at the front, meaning that you cannot get a useful angle to stop the boom from moving completely no matter how tight you winch that handle. The forces required, thanks to this angle, are greater than most ropes could cope with so more than likely your rope will snap and the boom will be moving even faster. If you use rope strong enough to not snap, your deck fittings will probably rip out and then you have a boom followed by a projectile.

The reason I continue arguing on this is precicely because people such as Angele believe the rope will stop the boom moving - it won't. Far better to educate people on the real use of the piece of rope and where it helps and when it's likely to fail. When at sea having the best information is more important than the best kit.
 
jimi said:
BTW tying a rope from boom to bow is not how I'd rig a gybe preventer , I'd rig it end of boom through bow cleat or similar and then back to a sheet winch, I then grind it in hard and in opposition to the mainsheet the boom ain't going anywhere until I release it off the sheet winch. Why don't you try that method yourself sometime?
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Thanks for that sarcasm. Have you considered that where the rope goes from the bow makes no difference to the physics of it being able to hold the boom? In fact you're more than doubling the length and therefore stretch of your rope making it more likely to allow the boom to move.

Keep cranking the winch though, you may just get it tight enough before the bow cleat rips out of your deck and gives you a nasty head injury.
 
lustyd said:
It might or might not. In ideal circumstances it will hold long enough that the problem goes away, or even better will slow the boom as it goes accross the boat (there are braking devices on the market for this).

Sadly physics is not on your side here if you have a sailboat since it's pointy at the front, meaning that you cannot get a useful angle to stop the boom from moving completely no matter how tight you winch that handle. The forces required, thanks to this angle, are greater than most ropes could cope with so more than likely your rope will snap and the boom will be moving even faster. If you use rope strong enough to not snap, your deck fittings will probably rip out and then you have a boom followed by a projectile.

The reason I continue arguing on this is precicely because people such as Angele believe the rope will stop the boom moving - it won't. Far better to educate people on the real use of the piece of rope and where it helps and when it's likely to fail. When at sea having the best information is more important than the best kit.
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Well you are wrong! It does and I can say that from experience. I have had accidental gybes with inexperienced crew at the helm. When I am worried that the person at the helm is not a strong helm and the risk of gybing is present, I put on a preventer. An accidental gybe has now happened on my boat twice when a preventer was fitted. Admittedly, both times in relatively light winds (max F4). But, because I do what Jimi says and winch in tight, the boom does not cross the centre line. Nobody gets hit with the boom and no damage done to the spars/gooseneck. Yes, I have gybed, because the wind is now on the wrong side of the boom, but turning back the other way soon corrects.

If it were not for the preventer, I would never let an inexperienced crewmember on the helm on a run. With one (and in winds below say 20 kts) then I am relaxed to let them have a go. No damage has resulted and the rope has done its job (and not snapped as you suggest it might).

Admittedly, I would worry about my deck fittings using a preventer with an accidental gybe in 30 knot winds, with 20+ knots apparent, although I would be heavily reefed by then, which would lessen the force.
 
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lustyd said:
Thanks for that sarcasm. Have you considered that where the rope goes from the bow makes no difference to the physics of it being able to hold the boom? In fact you're more than doubling the length and therefore stretch of your rope making it more likely to allow the boom to move.

Keep cranking the winch though, you may just get it tight enough before the bow cleat rips out of your deck and gives you a nasty head injury.
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Suggest you revisit your maths and trigonometry as well as your knowledge of ropes before displaying your ignorance

If you're using stretchy ropes for this you're a wee bit silly, I use my spinnaker sheet (which is static rope) where the shackle neatly fits the end of the boom.

Your maths is a bit dubious as well, the perfect angle would be 90 degrees from boom end to forward point, the narrower the angle the less good. on my boat from boom end I get an angle of roughly 66 degrees. If I attach mid boom I'd get close to 90 but I prefer the extra leverage and length of travel from the boom end.

This works for me and has done for the last ten years.
 
As I am away on a conference and posting via my phone I dont have the ability to quote some the tosh that has been written in this thread. I am all for writing things with novices in mind, but preventers have been called all sorts I'd things over the years and whilst they can't stop you gybing if you are really careless, they DO make sailing by the lee less hazardous if you stray off course as you roll down the swell. Perhaps for the pedants we should start calling preventers Gybe discouragers - but I am not serious. And yes I too sail lots of boats from the smallest up to over 100' in the past.

The preventer that I rig on our 39' boat is NOT just to stop the boom banging about. It's a safety measure and so long as it's braved up nice and tight and lead back to the cockpit we can alter to any point of sail very quickly.
 
lustyd said:
A Boom preventer does not prevent Gybes and is therefore not called a Gybe preventer. They are there mainly to stop the banging of the boom from the motion of the ocean and in no way help with accidental gybing.
The only time they actually do prevent Gybes will be when you're too close to the land and need to Gybe but can't because you tied the boom in place!
Cheers
Dave
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Hi, allthough I am a fairly new sailor-8 years-First mate and I have done a lot of sailing during this time.Every time we go out we learn something.We are fortunate in having a mentor who is vastly experienced, a Yachtmaster examiner and one of the senior Skippers out of the Joint Services Adventurous sailing centre at HMS Hornet in Gosport. He looked at my newly rigged preventer on a heavy downwind run outside the Owers on a passage to Littlehampton.He indicated a small improvement to the run of the line back to the winch but was otherwise happy. He made it clear that it was not a panacea against gybing-if the wind gets on the wrong side of the sail its effectivly a gybe-but he was happy that it would keep the boom where we wanted it.He asked me-and First Mate-what we would do if conditions got worse.He seemed happy with our reply that we would drop and secure the main and run under foresails only. We choose to run with "Front Wheel Drive" in heavy conditions as there is no risk of a flailing boom and our boat goes fast enough with a bit of genoa pulling it along. In light winds it is possible to goosewing our genoa and staysail with a preventer on the self tacking staysail. It works for us.
 
When solo and sailing downwind or close to downwind I always put one on, from the end of the boom to blocks at the shroud chainplates or mid cleat then back to the cockpit.

It's one less thing to be constantly concerned about and while it probably won't stop a cataclysmic event it certainly does stop the smaller problems that can interrupt my reading / fishing / drinking / sleeping / etc.....
 
lustyd said:
It might or might not. In ideal circumstances it will hold long enough that the problem goes away, or even better will slow the boom as it goes accross the boat (there are braking devices on the market for this).

Sadly physics is not on your side here if you have a sailboat since it's pointy at the front, meaning that you cannot get a useful angle to stop the boom from moving completely no matter how tight you winch that handle. The forces required, thanks to this angle, are greater than most ropes could cope with so more than likely your rope will snap and the boom will be moving even faster. If you use rope strong enough to not snap, your deck fittings will probably rip out and then you have a boom followed by a projectile.

The reason I continue arguing on this is precicely because people such as Angele believe the rope will stop the boom moving - it won't. Far better to educate people on the real use of the piece of rope and where it helps and when it's likely to fail. When at sea having the best information is more important than the best kit.
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This really is such utter tosh!

Whilst I was doing my pull ups in the garage I saw my climbing ropes and it dawned on me what complete and utter rubbish you are talking!

eg a stretchy climbing rope like the Beal 10mm Tiger has a static elongation of 10% and a first fall elongation of 37% (ie from zero tension to big load), climbing ropes are designed to stretch to absorb force so the climber does'nt die. Static (or semi static) ropes like pre stretchetched polyester sheets are about 5% stretch see http://www.riggingandsails.com/pdf/marlow-info.pdf

Now on a 35 boat with a 10 ft boom out at 90 degrees , you will need c 10/(12+12+12) ie 28% stretch to get the boom past the mid point. That I suggest is ridiculous.

Now as far as ripping your cleats out and projecting catapultlike at the crew .. well quite frankly if that's what happens on your boat , you're well overdue a bit of maintenance!

The breaking strain of prestretched 10mm polyester is roughly 2 tons
http://www.jimmygreen.co.uk/p/technical/rope-breaking-strain-guide
and if you've got 2 tons of weight at the boom end of a 30 odd foot boat then you're doing something wrong .. one of the reasons you've tensioned the thing in the first place is to abvoid shock loadings!
 
john_morris_uk said:
...t preventers have been called all sorts I'd things over the years and whilst they can't stop you gybing if you are really careless, they DO make sailing by the lee less hazardous if you stray off course as you roll down the swell. Perhaps for the pedants we should start calling preventers Gybe discouragers - but I am not serious. ....

..... It's a safety measure and so long as it's braved up nice and tight and lead back to the cockpit we can alter to any point of sail very quickly.
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My sentiments entirely.

Sailing by the lee can actually be useful for short duration course changes, and a preventer helps.
 
Once again another thread ruined by a debate which has nothing to do with the OP.
The question was how long from Falmouth to Plymouth on Sunday evening?
Given the winds forecast for that time, I would estimate that most of Falmouth would be in Plymouth within 30 minutes.
Nothing you could do with a rope would prevent that!
 
I suspect you won't make Plymouth, but will end up in Cardiff, with the rest of Falmouth.

I've always been dubious about preventers. If all goes to plan and it stops an accidental gybe without breakign anything, would you be able to steer or would it spin you round side on to the waves?

What I've done in the past is let the kicking strap off a lot so that you can sail a greater angle by the lee (unintentionally, of course). If you do then gybe acidentally, it takes a lot of the sting out of it too, as the bottom of the sail tends to gybe before the top.

New boat has a gas strut, so that won't work. Hmmm...
 
Once coming back through the Needles in over 30 knots of wind I had a gybe preventer set up and genoa poled out .. we were surfing well and almost planing , doing about 9 to 10 knots through the water (not bad for a Bennie 331) when TCM handed the helm over to Sinbad and it all went tits up (literally!!) as we broached.

HAving the gybe preventer line led back to the winch meant it was easily released and horizontality could be regained ;-)
 
longjohnsilver said:
Hi Jimi, I went mackerel fishing today and reeled in quite a few big ones. You seem to have had similar success. :D
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Oh dear; this all seems to be my (quite unintentional) fault.

I'd like to make it clear that I wouldn't actually rig a preventer, gybe or otherwise, in these conditions as I'd be running before the wind under bare poles and streaming a sea anchor/drogue/length of warp/the wife/whatever.

I don't know if it's possible to provoke a row about this suggestion, but anyone who wants to have a go (what's the best sea anchor, anyone?) is more than welcome ;)
 
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