Curious Double Fatality at Sea

Bristol-Cruiser

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Key advantages of in-boom furling compared to in-mast are a more efficient mainsail shape, and less weight aloft in shitty conditions when reefed.

Boats are a series of trade-offs.
I understand the advantages of in-boom but the more I learn about them, this case being an example, the less impressed I am for shorthanded (ma and pa), long-distance cruising.
 

billy backstay

Backstay, never bought a suit, never went to Vegas
I do not want ANY kind of furling main. The potential mess is huge with in-mast, plus the fact the main is like an old bedsheet. In-boom, as we see here, gives one a boom with the size and weight of a wrecking ball.

Drop it into lazy jacks, like the days of yore, problem solved!! Easy Peasy, Lemon Squeezy!
.
 

floater

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am convinced:
no matter how strong, well thought-out, no-traveller, whatever: if the motion of the boat is wild enough & the boom suddenly, after swinging it's full arc, comes to a stop against the sheet system: something is going to give.
not sure why you keep going on about rigging failure - utterly beside the point. there was no rigging failure.

You don’t center the boom , you don’t go head to wind to reef a roller boom

to reef you put the boat on a tack …, perhaps 60 degree awa
makes sense you would want to keep some pressure on the sail while furling.

From the article:
Annemarie readied the mainsheet in preparation for furling the main. As Escape came into the wind, the 2nd Mate noticed the boom was not centered per usual. During every other reef, the mainsheet was properly tensioned, centering it as Escape turned into the wind. The boom began to swing with the waves. Karl yelled instructions to Annemarie in German (the crew were not German speakers). Karl left the Genoa control lines and ran to the mainsheet winch to help. Annemarie stepped out of the way towards the portside winches.

As Escape was pitching while pointed into the wind her boom swung from starboard all the way to port. The mainsheet struck Annemarie..

so. the incident - as described here - is clear. the harm was caused by a loose mainsheet. and is it any wonder it was loose? depending on a 2:1 purchase - for a 60 footer - just seems insane. at some point, a seamanlike solution must trump aesthetics.

here are the conditions just prior to putting in the second reef:
a 40-knot gust began to round Escape up into the wind. The 2nd Mate put the wheel hard over all the way trying to maintain a course. Escape was heeled over, her rail near the water, she was barely holding course.

Karl called out for a second reef. The engine was started, everyone took their normal stations. Karl gave the go signal and the 2nd Mate headed Escape into the wind. Waves now nearing 8 meters were crashing over the deck, her bow was rising high then pitching down. Gulf Stream waves were coming from different directions in the confused seas. Karl was at the controls starting to furl in the Genoa before attending to the main. Annemarie was behind the mainsheet winch, central in the cockpit just ahead of the twin wheels.

so. they were knocked over. and it seems to me that the crew were not able to control the boat. And neither Annemarie nor Karl was able to control the mainsheet.
 

slug zitski

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not sure why you keep going on about rigging failure - utterly beside the point. there was no rigging failure.


makes sense you would want to keep some pressure on the sail while furling.

From the article:


so. the incident - as described here - is clear. the harm was caused by a loose mainsheet. and is it any wonder it was loose? depending on a 2:1 purchase - for a 60 footer - just seems insane. at some point, a seamanlike solution must trump aesthetics.

here are the conditions just prior to putting in the second reef:


so. they were knocked over. and it seems to me that the crew were not able to control the boat. And neither Annemarie nor Karl was able to control the mainsheet.
It’s hard for me to understand how this accident happened

it’s possible that the autopilot malfunctioned causing the crew to loose optimum wind angle for reefing

typically you hand drive to find the sweet spot..then engage auto, time the wave train , then reef

when I first read of the accident I also considered possible electrocution

on many larger boats you start the generator to power an AC hydraulic power pack

that boat is right on the edge of DC power pack ability

the power pack must simultaneously power the captive main halyard winch , boom vang and the boom roller…that requires substantial oil flow
 

Tylo

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I still think, given how the boom is resting on the sprayhood in the pictures (both of the recovered boat and those of the boat at sea) and the following account in the BWSailing article, that there may have been a failure of the hydraulic vang:

Annemarie readied the mainsheet in preparation for furling the main. As Escape came into the wind, the 2nd Mate noticed the boom was not centered per usual. During every other reef, the mainsheet was properly tensioned, centering it as Escape turned into the wind.

I read this as that Annemarie was sheeting in the main as the boat was coming up into the wind (though English isn't my first language so I could be wrong). I think someone else described it earlier in this thread; a small leak in any of the hydraulics related to the vang could result in the ability to get the mainsheet tight but as the boom swings and puts pressure on the vang, it gets compressed, effectively slacking the mainsheet again.

I think this could also explain how seasoned sailors like these people seem to have been were caught off-guard by the boom/mainsheet; you wouldn't expect the mainsheet to go slack after you've tensioned it once and haven't let any line off the winch. In the report they describe the mainsheet causing the two terrible injuries before snapping, so I wouldn't have thought it was initiated by a failure of the sheet itself.

I thought about the possibility of the anchoring point in the deck, ahead of the winch in the picture below, failing and getting caught in the block on the boom, making the mainsheet 1:1 and twice as long but I think this would have been noticed by the crew and part of the report. The fact that they mention boom not being centered (sheet not being tight) so casually suggests to me that it was something that caught them off-guard without an obvious reason as to why. That's why my primary suspect would be a slow leak in the vang. I'm just speculating though, I don't have much experience with big boats like this but for future reference it would be good to know what caused all of this.

1658950891421.png
 

longy

Overlord of Anarchy
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Having wrenched & delivered a 63' Dubois custom that had in boom furling: the angle of the boom to the mast is CRITICAL when lowering the sail. A wrong boom angle would cause the bolt rope to either creep forwards or aft. Forward, the roll would jam the gooseneck, aft, the bolt rope would pull out of the track. That boat had a solid plastic spacer that would be placed over the exposed vang rod, then the vang would be pumped down solidly onto the block. This would insure the proper angle for operation. Wind angle - rolling could be done anytime the exposed sail could luff, the boat did not have to go head to wind.
Going downwind on a large boat it is easy to defer reefing until too late. I had one occurance of that, sailing back to SoCal from Hawaii. Got a bit pressed with the full main & solent on a very broad reach and did not want to secure evrything above & below to allow us to head up enuff to reef. So got rid of the solent, headed up a bit, & sailed a large Laser all night until breeze fell off. Not a problem in the middle of the ocean. Sea state was moderate. We were hand steering - auto had failed due to a waterlogged splice taking out the entire B&G system. % man crew of experienced offshore sailors so no worries about helming
 

slug zitski

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Having wrenched & delivered a 63' Dubois custom that had in boom furling: the angle of the boom to the mast is CRITICAL when lowering the sail. A wrong boom angle would cause the bolt rope to either creep forwards or aft. Forward, the roll would jam the gooseneck, aft, the bolt rope would pull out of the track. That boat had a solid plastic spacer that would be placed over the exposed vang rod, then the vang would be pumped down solidly onto the block. This would insure the proper angle for operation. Wind angle - rolling could be done anytime the exposed sail could luff, the boat did not have to go head to wind.
Going downwind on a large boat it is easy to defer reefing until too late. I had one occurance of that, sailing back to SoCal from Hawaii. Got a bit pressed with the full main & solent on a very broad reach and did not want to secure evrything above & below to allow us to head up enuff to reef. So got rid of the solent, headed up a bit, & sailed a large Laser all night until breeze fell off. Not a problem in the middle of the ocean. Sea state was moderate. We were hand steering - auto had failed due to a waterlogged splice taking out the entire B&G system. % man crew of experienced offshore sailors so no worries about helming
Typically the boom angle is monitored by a proximity sensor inside the boom vang

when you press the up or down mainsail button…. the first sequence is for a hydraulic valve controlling the vang to open…the boom then rises into position via gas pressure , with the proximity sensor triggered the winch and boom roller are now energized and you reef or hoist

the vang will be fitted with mechanical stops that prevent to boom from rising too high when the vang is eased



it’s pretty fool proof

to make the system even more foolproof …especially at sea in a sea way, you tension the boom topping lift

this topping lift tension prevents the boom from moving in an arc and constantly triggering the boom proximity sensor as the boat rolls

in general the system is very reliable

in boom furlings flaw , and one that can’t be solved, is the compression load of the battens destroying the luff tape

leech lines…to control flutter are also problematic …I’ve never met one that I liked
 

longy

Overlord of Anarchy
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The system I described seems much more fixed - once the vang was two blocked on the spacer, that boom had no ability to change vertical angle. No reliance on sensors, gas pressures, or playing with the topping lift needed. Most sailing the spacer could be left in, as the sail was cut slightly higher at the clew.
 

slug zitski

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..."proximity sensors"..."hydraulic vang"..."generator"..."electric winches" - - "foolproof": find the flaw!
If you choose to own a big powerful sailing yacht you have two choices

an electro hydraulic furling system or you hire a professional seaman and go with a manual slab system

professional seaman are scarce and cost 100 k per year

i sailed a big swan with a conventional main …at the end of the day it took two crew working hard for about 45 minutes to organize the mainsail on the boom, tidy up all the mainsail control lines , fit the mainsail cover

with an electro hydraulic system this work , this crew work is not required

as for boom vangs and boom angles . I’ve sailed a few different systems

the common reverse gas pressure vang , modified to suit the system is the most commom

since gas pressure is keeping the boom up …agaisnt its stops , in the correct boom up , hoist furl position …it must be kept stationary

when the boat rolls , with no mainsail leech tension , the boom will cycle in an arc …boom up at the top of the arc and boom down , compressing the gas vang , at the bottom of the roll arc

the topping lift prevents this motion and ensures that every hoist , furl cycle is successful
 

Matagi

Ambassador of the Republic of R'lyeh
If you choose to own a big powerful sailing yacht you have two choices

an electro hydraulic furling system or you hire a professional seaman and go with a manual slab system

professional seaman are scarce and cost 100 k per year

i sailed a big swan with a conventional main …at the end of the day it took two crew working hard for about 45 minutes to organize the mainsail on the boom, tidy up all the mainsail control lines , fit the mainsail cover

with an electro hydraulic system this work , this crew work is not required

as for boom vangs and boom angles . I’ve sailed a few different systems

the common reverse gas pressure vang , modified to suit the system is the most commom

since gas pressure is keeping the boom up …agaisnt its stops , in the correct boom up , hoist furl position …it must be kept stationary

when the boat rolls , with no mainsail leech tension , the boom will cycle in an arc …boom up at the top of the arc and boom down , compressing the gas vang , at the bottom of the roll arc

the topping lift prevents this motion and ensures that every hoist , furl cycle is successful
I see what you mean and mostly agree. But wouldn't that be the equivalent of buying a private jet but not the professional pilots? Sure you can fly on your own. But if the weather deteriorates, the workload gets so high that two pros might struggle.

I have the hunch that many owners who buy yachts this big have no clue about the loads they buy with them. On a large CNB 76 for example, this might be even higher than on an IMOCA.

You don't realize it, until the system fails and in most instances are not trained for that.
 

eastern motors

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What about don't sail DDW or an angle that requires a preventer as a lesson learned? Exception for full crew. 8m seas in the gulf stream is going create a pretty decent chance of accidental gybe. As others have said, you can carry sail area DDW that you can't effectively reduce. Just gybe downwind and take an extra day to get there.
 

slug zitski

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What about don't sail DDW or an angle that requires a preventer as a lesson learned? Exception for full crew. 8m seas in the gulf stream is going create a pretty decent chance of accidental gybe. As others have said, you can carry sail area DDW that you can't effectively reduce. Just gybe downwind and take an extra day to get there.
It’s speculation but another failure point could be the electro hydraulic mainsheet winch

those winches turn fast

When in self tailing mode ….overrides …with the mainsheet tail getting sucked into the drum during a maneuver is a common problem , dangerous to anyone close-to the sheet and it stops the maneuver until you clean up the mess
 
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kent_island_sailor

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I see what you mean and mostly agree. But wouldn't that be the equivalent of buying a private jet but not the professional pilots? Sure you can fly on your own. But if the weather deteriorates, the workload gets so high that two pros might struggle.

I have the hunch that many owners who buy yachts this big have no clue about the loads they buy with them. On a large CNB 76 for example, this might be even higher than on an IMOCA.

You don't realize it, until the system fails and in most instances are not trained for that.
You don't necessarily have a choice in the way the boat owner does. Many jets legally require a copilot. If you don't hire one, you'll need to train your wife or kid or something. Speaking of training, for a long time now there has been one standard for passing the type rating checkride, so while you may not be a professional pilot, you'll be held to the same standards and pass the exact same checkride. On top of that your insurance company will have all kinds of extras they throw in, like your first X hours with a hired professional riding along and annual recurrent training.
Just like the big boat, the single pilot is relying on a lot of automation to make life easier. But the big boat can very much be owned and operated by someone with no experience and no training whatsoever and for sure no annual recurrent training on how to fly/sail it with all the advanced labor-saving devices failed.
 

floater

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One lesson I learned, skip the boom furler, and stick with simple. Just saved myself $50k. lol.
makes no sense, as this accident seemed to have little or nothing to do with roller furling. the incident entirely within the cockpit - and the problem was the mainsheet.

It’s speculation but another failure point could be the electro hydraulic mainsheet winch

those winches turn fast

When in self tailing mode ….overrides …with the mainsheet tail getting sucked into the drum during a maneuver is a common problem , dangerous to anyone close-to the sheet and it stops the maneuver until you clean up the mess
and this explains everything.

I would speculate. as well. that handing the helm over to guest crew was a surprising choice.
 
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