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Old 15-10-2012, 15:48   #376
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Originally Posted by Andrew Troup

I attach a photo which should kill two birds with one stone - earlier in the thread people were talking about sailing in strong conditions under staysail alone - this shows us happily balanced under such a rig, and although you can't see it in the photo, the running backstays from the top spreaders (3 spreader rig, staysail stay to the top spreaders, babystay to the second set) are BOTH set up hard, making the mast column wonderfully stable.

In the photo, both preventer/vang purchases are set up against the topping lift, keeping the boom stable. It's not obvious from the photo but this is a pretty generous sized boom for a 40', as it's a Leisurefurl with a tall rig (and a deep fin keel with a ballast bulb)
The concern i would have with your setup is how the plate is attached to the boom. During an accidental gybe the full pull would be straight out which means only the rivits or screws would be holding the plate on. The force would pull threads or rivits clean out. Are the bolts? Are they backed with a plate? If they were that would be a very nice setup. I would still have concerns with it set so far forward on the boom but it looks very easy to set and use.
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Old 15-10-2012, 15:50   #377
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Re: sailboats can injure and kill

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Originally Posted by s/v Beth View Post
Excellent setup Andrew. The only part of it I don't like (for obvious reasons) is the mainsheet coming into the cockpit. What kind of speed where you making into the wind? Where were you?
The multiple purchase was something I had worried about, just had not voiced. I usually run my lines through a clutch then a grinder. Just seems to be a good combination.
Newt

Make sure the alignment of the clutch is OK for the winch if you're going to use both; a line passing axially through the clutch should rise undeviated at about a 5 degree angle to meet the winch in the correct place, at the bottom of the drum on the correct side. I'd only recommend doing this if you need the winch to serve a dual purpose: using the clutch to surge the tail under heavy load is neither safe nor conducive to line life.

We were broad reaching when I took the photo, approaching Puysegur Point (one NZ's great capes), logging about eight and a half through the water.

This was us snatching a weather window to get around the corner during a trip around the South Island.

The forecast was for 60 knots, which in the old days would have meant gusting to 80 or 90, but these days you have to be pretty unlucky for the forecast speed to exceed what it says on the bottle, unless the weather system is complex.

The forecast was the best we'd had for a fortnight, and the best we were likely to get for another three weeks.

In that part of the world, it's the direction, not the strength that matters, when deciding whether to stay or go.

So ... when I say "weather window", it's not for laconic effect. The two crucial factors were that it was very simple classic cold-front, large scale system, with no signs of any secondaries developing. And no prospect of the change to the SW happening within the time we would take far enough into Foveaux Strait to get to shelter from it. Even a moderate SW is a showstopper for that particular itinerary.

In addition, by leaving before dawn, we had a tidal flow which was strongly aligned with the wind for the duration. Consequently the seas were entirely manageable, which would not have been the case six hours later. And our speed across the ground was increased, making the miles fly by.

I'm not recommending this strategy be exported to a wider context, but we had a great trip under a very specific set of circumstances.
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Old 15-10-2012, 16:08   #378
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Re: sailboats can injure and kill

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Originally Posted by foolishsailor View Post
The concern i would have with your setup is how the plate is attached to the boom. During an accidental gybe the full pull would be straight out which means only the rivits or screws would be holding the plate on. The force would pull threads or rivits clean out. Are the bolts? Are they backed with a plate? If they were that would be a very nice setup. I would still have concerns with it set so far forward on the boom but it looks very easy to set and use.
Good point, foolishsailor, and I should have mentioned that. There's a larger, fitted plate of 6mm stainless inside the boom on each side, tapped for a multiplicity of decent sized high quality 316 cap-head screws, and then nutted for good measure, with Loctite. The outer plate is heavily gusseted and both plates are larger than the photo might suggest, especially in the fore-and-aft dimension, and are fitted on mylar insulating pads, each smeared with bedding compound both sides.

On the maiden voyage of that same boat a good sailor (a 'pickup' member of the crew') became disoriented during the first night, which was very black (he was unused to wheel steering, and became hypnotised by the compass card) and he gybed accidentally, twice in quick succession, onto a slack preventer when we were running before a building gale.
This caused the 100mm heavy Ocean block to shed its balls all over the deck, and him to shed his enthusiasm for what, to him, was 'big boat' sailing.
I should explain that we had a bit much sail up because the Leisurefurl was new to us and we'd had difficulty reefing without coming up to the wind, which would have meant a rude awakening for all the offwatch crew (being a maiden voyage, we were dog tired from all the preparation work, and I even managed to sleep through the first of the accidental gybes).


All this by way of explaining that ten years later, with stronger blocks fitted, and the vessel having made numerous trips around NZ and the Pacific, often ridden hard and occasionally carrying scratch crewmembers of varying degrees of experience and finesse, the mounting of the blocks to the boom looks as it did when fitted, to the closest inspection.

I was concerned that it might spring the top of the Leisurefurl boom open slightly, so I kept the block low - when I make the tangs for conventional booms, I generally place the block a little higher than shown, so the midline of the hauling parts of the tackle bisects the longitudinal rotation axis of the gooseneck.
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Old 15-10-2012, 16:08   #379
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Re: sailboats can injure and kill

I think very few of us are going to sail in 60 knot winds on a regular basis. Heck, 10 ft swells and 30 knot winds cause me to cancel the day out here. That said:
I never thought of the clutch being a weak spot. We use them for halyards and all types of sheets. Would you stay with the tradition grinder and cleat? Or the self tailing winch (which I am eventually converting everything over to)?
Your sail- Storm Jib or Staysail? What oz dacron?
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Old 15-10-2012, 16:27   #380
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Re: sailboats can injure and kill

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Wow, that's an impressive photo! What kind of boat is that - 40 feet and three spreaders?! Must have quite a wind to make a 45 degree heel with staysail alone!
It's a one-off, Dick McBride design, built in strip-plank/epoxy/glass with a few (homebuilt) carbon fibre bits - eg quadrant and rudderpost.

From memory the stick is 67' off the deck, masthead rig, swept spreaders.

Deep spade rudder, beautiful manners, powerful lines without being cranky in the slightest degree... in fact I'd be hard put to think of a vice. Not outstanding performance hard on the wind in harbour racing, but sails exceptionally efficiently on that point of sail in a seaway offshore, which can be a blessing, particularly getting around capes.

The big main (full length battens, generous roach) means she can make good speed in light winds without changing up from a #2 headsail - again, a blessing offshore.

Having said all that, I'm not totally won over by in-boom furling, but that's another discussion.
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Old 15-10-2012, 16:54   #381
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Re: sailboats can injure and kill

G'Day Newt,

Andrew is doing a good job of promoting this setup, and his experience seems a lot like our own in use of the preventers.

As far as the use of a clutch -- what he is saying is that the clutch needs to be well aligned with the winch, and that you must use the winch as a snubber when easing the boom across under load. But it is ok to use the clutch to free up the winch for other uses... just switch the vang tail back to the winch for easing. In fact, this is exactly what we do on Insatiable II. We use a three part tackle, lead through a Spinlock clutch to a Barient 27 to load it up and to allow controlled easing. Our mains'l is about 62 sq metres in area, boom is about 6 metres long, and we use 12 mm dacron doublebraid for the vangs. In practice this line is stretchy enough to take out most of any shock loads that are developed. As mentioned before, we use a webbing strop to attach to the boom... something that Andrew can't do with his Leisure-Furl boom, hence his more complicated attachment system.

Cheers,

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Old 15-10-2012, 17:01   #382
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Re: sailboats can injure and kill

G'Day Andrew,

Nice photo! And I appreciate your planning for getting around a very difficult bit of coastline and water. Friends of ours got stuck for 6 weeks at Stewart Is trying to get out westbound. They were in a smaller boat and got driven back several times... but they still went back for another visit a few years later!

Your boat sounds like a boomer! A 67 foot masthead spar on a 40 footer is pretty huge! What is her SA to Disp ratio? For comparison, our fractional rig has just about the same mast height on a 46' LOA 44' LWL hull (also strip plank composite).

Cheers,

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Old 15-10-2012, 17:02   #383
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Re: sailboats can injure and kill

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Originally Posted by s/v Beth View Post
I think very few of us are going to sail in 60 knot winds on a regular basis. Heck, 10 ft swells and 30 knot winds cause me to cancel the day out here. That said:
I never thought of the clutch being a weak spot. We use them for halyards and all types of sheets. Would you stay with the tradition grinder and cleat? Or the self tailing winch (which I am eventually converting everything over to)?
Your sail- Storm Jib or Staysail? What oz dacron?
I'm more saying that a clutch will damage the line if it's routinely used for surging out a load, and that it's more difficult and dangerous coping with such loads through a clutch.

By 'grinder' I guess you mean a plain winch? If I was only allowed one pair of self-tailers, I would probably use them for the vang-preventer tails.
Partly because the convenience helps encourage their routine use, even when the boom is constantly being trimmed; also because in an emergency it's much easier to uncleat than a separate cleat with a plain winch.

I'm not concerned about the line coming uncleated, partly because I've never had it happen but more importantly because I always throw an extra wrap around the drum before cleating, and a multipart tackle tailed with three or more turns round the drum will act as an automatic boom brake (slowing the swing below the danger threshhold) even if not cleated.

There's a fringe benefit with toerail vangs which I don't remember seeing further up the thread: they're great for minimising chafe against the spreaders and stays, because the angle at which they pull is optimal for preventing 'panting' of the sail. This is particularly important with swept spreaders on ocean passages.
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Old 15-10-2012, 17:34   #384
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Re: sailboats can injure and kill

Newt - I forgot to answer your other question: this was a storm staysail.
The rough proportions can be guessed from the photo, it's a triple-spreader rig, and the head of the sail is not that far above the first spreader.

I don't personally think there's a need for storm sails in such small sizes to be particularly heavy, small sails are fantastically strong out of Dacron and I reckon it's the detailing which is the key factor - I think this one is 12oz.

And for the record: unless circumstances extenuate I would share your inclination to pass on conditions half as windy. Given the choice !

(in the above scenario - I didn't mention we were in an uninhabitable part of the mainland, where overland travel is not realisitically possible, winter was coming, and we probably had only a month's food left)

(ON EDIT: and an iceaxe, but no guns!)

Jim: It's not my boat, more's the pity. Displacement as designed was IIRC 6500kg, I think the crane driver said 7200kg at launch (when was the last time you heard a boat come it at, let alone under, design displacement?)

I think I perpetrated a Clinton on rig height - try 67' off the water! Mea culpa.

Clue: When I prefix a claim with 'From memory', it's a bit like Paris Hilton saying 'On reflection...'
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Old 15-10-2012, 18:17   #385
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Re: sailboats can injure and kill

Newt (and Andrew T, et al).
Great discussion but don't forget to add a boom brake to the list.
Not so much for preventing a gybe (although they do help greatly) but for easing loads (especially impact loads) during an accidental or deliberate gybe. I'd much rather be applying almost hand-held loads to a boom brake than paying out a preventer during a gybe.

Cheers, Andrew G
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Old 15-10-2012, 19:24   #386
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Re: sailboats can injure and kill

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Newt (and Andrew T, et al).
Great discussion but don't forget to add a boom brake to the list.
Not so much for preventing a gybe (although they do help greatly) but for easing loads (especially impact loads) during an accidental or deliberate gybe. I'd much rather be applying almost hand-held loads to a boom brake than paying out a preventer during a gybe.

Cheers, Andrew G
I used to be a great fan of boombrakes, too, but for two reasons I now gravitate towards vang preventers:

1) When rigged as suggested above, with suitable purchase ratio and a couple of turns (three in extreme conditions) around a winch, they're at least as good as any of the brakes I've tried (which includes prototypes too expensive to be viable on the open market). There's nothing 'almost handheld' about the loads, they're literally within the capabilities of any ten year old child whose concentration span has not been modernised.
All that happens, when you swap this for a boombrake, is that the source of friction shifts from somewhere near at hand to somewhere further away: the principles are essentially the same.

Theres the added advantage that you can choose the appropriate amount of friction to suit the conditions each time you load the winch. Most boombrakes are set to a compromise value for friction.

2) I love light air sailing, and a boombrake kills some of the pleasure for me. I say this because it means that in such conditions, you generally have to go forward and push the boom outboard whenever you ease the mainsheet. (I don't mind the activity, but moving unnecessarily about the boat is not ideal in light going, and it's hard to do everything smoothly when you're hand steering)

Given that light fluky conditions generally require continual adjustments to gross trim, I find that having a vang purchase on each side is even better than dispensing with a boombrake. It means you can finesse the boom outboard with the tackle, even in the situation where the boom would not go there voluntarily.

And it means the tails of the vang preventer tackles become part of the way you interact with the boom in all conditions, so that it becomes second nature to always have the boom under strict positional control, like a well trained dog walking at your heel.
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Old 15-10-2012, 19:41   #387
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Re: sailboats can injure and kill

When I first started fitting preventer vang tackles, I used a ratchet block on each side of the boom to enhance the 'brake' function. I still do that on rigs too small to need a winch, say up to 25' with a 2:1 purchase - but once you get much above that size even the strongest ratchet blocks are simply not strong enough, in my experience. And, as noted above, tailed around a winch, it's just not necessary.

NOTE: you can buy 'snubbing winches' which do not have a drive mechanism or handle socket, which would be ideal for dedicated preventer winches.
(A nice way of pre-empting the problem of an end-sheeted mainboom, a mid-boom preventer tackle attachment, and a careless crew, possibly bending the boom - mentioned further up the thread)

It's not widely known that you can actually get them up to superyacht size, for use instead of clutches, for the reasons I mentioned in an earlier post.

These ideally have a top cleat, but I don't recall seeing such a beast in smaller sizes. Now there's an opening for someone !

I reckon there's probably a way of doing it, with a roller stripper arm, a bit like a Harken/Barbarossa, but leading the sheet into a diametral pass above the drum, through a decent heavy metal cam cleat - both non-rotating relative to the coaming - which would provide a very nice user interface. Gentlemen, start your CAD packages !

Another layout which has some advantages, particularly for single handing, is to use a single line to service the tackles on both sides. Imagine taking an existing setup, shortening the tails on each side, then joining them with an invisible end-to-end- splice, so a single loop ran around behind the coaming (only works for some cockpit layouts)
In one instance I rigged a topping-up block from a bungy suspended from the backstay terminal to keep slack out of the system, and to prevent the line chafing the tiller where it passed over it.

On the systems I fitted out with ratchet blocks, I would flip the line outboard of the stern quarter cleats when I wanted the system to self-tend, ie act as an automatic brake (no turns around any winches), if I was single handed and doing some particularly busy manoeuvre in moderate conditions.

I've since become so accustomed to adjusting the tackles I don't use this last function, but someone may find the idea useful.

The advantage (apart from saving line and the associated spaghetti soup on the cockpit floor - particularly with say a 3:1 purchase where the tails otherwise need to be really long) is that there are no stopper knots to jam themselves at inopportune moments in locations which are hard to reach when you've a mouth full of sheets and one toe on the helm. Against that, sailing with crew, the endless tail idea is prone to being sat on at some point in its circumnavigation of the cockpit, which can be frustrating. Best situation is where the coaming has an overhanging lip, like the breakwater on the foredeck of a military ship.

Obviously if you have a walkthrough transom, you'd want to fit the topping-up block above head height.
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Old 15-10-2012, 20:00   #388
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Re: sailboats can injure and kill

Andrew T,

I think you mis-read me. I said "add a boom brake" - not "swap".
I don't disagree with what you are saying except an appearance to somewhat play down the virtues of a boom brake.

Comments in { } below,

Cheers Andrew



"I used to be a great fan of boombrakes, too, but for two reasons I now gravitate towards vang preventers:

1) When rigged as suggested above, with suitablepurchase ratio and a couple of turns (three in extreme conditions) around a winch, they're at least as good as any of the brakes I've tried (which includes prototypes too expensive to be viable on the open market). There's nothing 'almost handheld' about the loads, they're literally within the capabilities of any ten year old child whose concentration span has not been modernised.
All that happens, when you swap this for a boombrake, . . . {I'm saying use the b-brake to control gybes, and help prevent accidental ones}

2) I love light air sailing, and a boombrake kills some of the pleasure for me. I say this . . ." {then slacken off the boom brake and play the other controls - use it in other than "light" conditions}
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Old 15-10-2012, 20:16   #389
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Re: sailboats can injure and kill

Since a picture is worth a thousand words. Here is a preventer that also acts as a vang that went around the world. Nuff said.
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Old 15-10-2012, 20:17   #390
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Re: sailboats can injure and kill

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Just read that a sailor was killed on the boat he was racing on in Virgina...Hit by a boom? Re read the article,said he fell from the windward side of the boat and cpr was performed to no avail...got to be real careful out on the deck ,said he had no life vest on ...
Sailor in Bay schooner race knocked overboard, dies | HamptonRoads.com | PilotOnline.com

Full crew, experienced sailor still means no guarantees on the water. Just remind yourself Newt you had some luck on your side.
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