Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 16-02-2008, 05:47   #76
CF Adviser

Cruisers Forum Supporter

Join Date: Dec 2007
Location: Wherever our boat is; Playa Zaragoza, Isla Margarita
Boat: 1994 Solaris Sunstream 40
Posts: 2,439
Rob - thanks for the clarification. This thread had started with a concern expressed by a new (to be) owner of a cruising cat about capsizes in the same due to the lack of experience of the skipper. My concern was that many would read your post as an indication that cruising cats commonly capsize; seems we are all in agreement that it is a very rare occurence indeed.

Another recent capsize of a cruising cat occurred last year around this time, as I recall, about 250 miles east of Bermuda. There was a thread on it in themutihull.com last year - the crew of three managed to get on the overturned bridgedeck, but unfortunately the owner was washed off by a wave before they could be rescued.

Initially there was some debate about the brand/model, but another thread here led me to believe that it may have been a Lagoon 440 ( in any case, there was a discussion recently under the Lagoon thread about a capsized 440 and I assume it was the same incident - at least, I hope so).

So yes, capsizes in cruising cats are exceedingly rare, although not impossible. There have been other postings on this site (including some photos) just in the three months that I have been a member. I guess my hope is that just as we shouldn't be alarming prospective purchasers of a cruising cat by over-stating the risks, we also should not be under-stating them. To me, at least, this is a topic worthy of discussion precisely because it can and does occur, however infrequently.

Brad

Brad
__________________

__________________
Southern Star is offline   Reply With Quote
Old 16-02-2008, 06:27   #77
Registered User

Join Date: Oct 2007
Location: Winters cruising; summers Chesapeake Bay
Boat: Catana 471
Posts: 1,239
Quote:
Originally Posted by Southern Star View Post
There was a thread on it in themutihull.com last year - the crew of three managed to get on the overturned bridgedeck, but unfortunately the owner was washed off by a wave before they could be rescued.

Initially there was some debate about the brand/model, but another thread here led me to believe that it may have been a Lagoon 440 ( in any case, there was a discussion recently under the Lagoon thread about a capsized 440 and I assume it was the same incident - at least, I hope so).
Hi Brad - the event last February when someone was washed off the overturned bridgedeck I think was a 380 being delivered and the guy lost was the delivery skipper. Very sad and not an indictment of the boat - an indictment of February weather in the North Atlantic.

If it had been a 440 I bet some folks would still be arguing how much the design contributed/did not contribute to the example.

You'll never see me in the North Atlantic in February on any boat. That said, I once made a passage in the N. Atlantic in January, but we didn't see any weather whatsoever.

Dave
__________________

__________________
2Hulls is offline   Reply With Quote
Old 16-02-2008, 06:58   #78
CF Adviser

Cruisers Forum Supporter

Join Date: Dec 2007
Location: Wherever our boat is; Playa Zaragoza, Isla Margarita
Boat: 1994 Solaris Sunstream 40
Posts: 2,439
Thanks Dave

Then there must have been another recent incident involving a 440, or I mis-read the postings. My point was not to attack a particular boat, but to respond to the statement in a previous post to the effect that 'I am not aware of any capsize of a cruising cat in the last 20 years'.

Yes, the North Atlantic can be treacherous in February. On the other hand, as I recall the winds were reported as being under 50 knots and the seas difficult, but without huge breaking waves. These are conditions that in an offshore passage, one might unfortunately encounter at any time of the year (albeit with less frequency in many areas during many months). A properly prepared and handled boat should be able to handle these conditions (at least one intended for offshore passages).
I believe that you are correct that this was an experienced (British?) delivery skipper, rather than a complete neophyte. Still, somehow I suspect that your Catana would have fared better in the circumstances...

Regardless, the point is that cruising cats can and do capsize. The design/construction of the boat is a factor, but so too is seamanship and preparation for the worst - both to avoid a capsize and to survive thereafer, should the unthinkable occur. The latter are what this thread was about.

I apologize for mistakenly suggesting that the boat in question in this incident may have been a Lagoon 440, rather than a 380, but the point remains the same.

Brad
__________________
Southern Star is offline   Reply With Quote
Old 16-02-2008, 07:13   #79
Senior Cruiser
 
colemj's Avatar

Cruisers Forum Supporter

Join Date: Oct 2005
Location: Presently on US East Coast
Boat: Manta 40 "Reach"
Posts: 10,049
Images: 12
The capsize of the Lagoon 380 was initially reported as a L440 and corrected later.
__________________
colemj is offline   Reply With Quote
Old 26-02-2008, 18:11   #80
Registered User

Join Date: Feb 2008
Posts: 2,061
This is about the proverbial "Line of Death"

Hi all -
This is my first post here -- I picked up the thread via a web search, and it caught my interest. Dave (2Hulls) knows me as Larry s/v Symmetri from the cs-bb forum, and Steve B knows me as a fellow Dragonfly 1000 owner, but Symmetri is now sold and I decided to pick another handle. I have owned a Dragonfly 920, 1000, and now a 1200. Prior to that I started with Sunfish in the 1960's and owned and sailed lead-sleds most of my life.

This really is an important subject, and the expression "Line of Death" is spoken with a bit of a smile and indented sardonic wit. I wrote my 2 cents about it back in 2005 on another bbs (Heavy weather multihull tactics (re: #4) (pic)) and other times too.

This issue of heading up vs. heading down is a fundamental tactical difference in heavy weather multihull sailing vs. displacement monohull sailing. While the displacement mono tactic is to round-up, the greater speeds and initial stability of a multihull can make that dangerous unless you're already on a close beat (in which case you're better off to just ease the sails rather than head up -- and further increase apparent wind).

Someone else in this thread "nailed it" in mentioning centrifugal forces of the boat and weight aloft as working in your favor to force the windward hull down, and at the same time the downwind acceleration of a multihull allows immediate reduction of apparent wind, so the faster you make that turn -- the better.

One more very important point to add which hasn't been mentioned here is that full-battened main with low-friction (preferably ball-bearing) batt-cars is an essential multihull safety item, IMHO. In overpowering conditions it is ONLY possible to reef the main downwind if you have that equipment. Regular sail tracks and slides (and especially bolt-rope luffs) will not allow downwind reefing when pressed hard. If you can't reef while running downwind then you're trapped in a run to leeward because a turn (to a reach, or especially rounding upwind) will make apparent wind rise and you may cross the "line of death" that results in capsize.

The other very important advice to any new multihull sailor is to reef for the gusts, not for the average wind strength. That will improve comfort and safety greatly, and shows good judgment. That judgment is generally lacking in racers who are trying to ride the edge of performance limits, which is of course why so many racers capsize (and make unfortunate headlines).
__________________
SailFastTri is online now   Reply With Quote
Old 26-02-2008, 22:09   #81
Senior Cruiser

Cruisers Forum Supporter

Join Date: Dec 2006
Location: Seattle
Boat: Cal 40
Posts: 2,401
Images: 7
Zone of death continued

Another 2 inches of depressing the bow and I would have had the full experience of the zone of death on my Hobie 20 trying to get it to turn downwind from a close reach in a blow. There is a great video of Aussie 18 skiffs racing in wind making two or more attempts to round down after the weather mark to avoid pitchpoling, and I 've talked to 49'er sailors who have had that fun, but it seems to me unless your multi is a lot more of a race boat than a cruiser then you are not going to be carrying the apparent wind forward and increasing it with your increase in boatspeed as you turn downwind (or upwind through the zone of death) to make much difference. Not that I did testing or had enough wind, but neither the Privilege 39 or the Kennex 445 that I have chartered showed anywhere near the performance that would lead me to worry about whether to choose heading up or down.

Though I would be happy to be corrected by those with more experience with boats that have a cruising level of performance!

Here's a polar of a Privilege 445

Choose Range, Privilege, 445, specs, polars.

Alliaura

John
__________________
cal40john is offline   Reply With Quote
Old 26-02-2008, 23:33   #82
Registered User

Join Date: Feb 2008
Posts: 2,061
Quote:
Originally Posted by cal40john View Post
snip -- Not that I did testing or had enough wind, but neither the Privilege 39 or the Kennex 445 that I have chartered showed anywhere near the performance that would lead me to worry about whether to choose heading up or down.

Though I would be happy to be corrected by those with more experience with boats that have a cruising level of performance!

Here's a polar of a Privilege 445

Choose Range, Privilege, 445, specs, polars.

Alliaura

John
John -- if you haven't had the experience in the Privilege 39 or the Kennex 445 then you weren't pressed to the limits of stability. That's a good thing.

Either of those boats are capable of sailing above 10 knots in a good blow and if you would consider the difference between upwind and downwind may be a change of 20 knots apparent then you should clearly understand the important difference between rounding up and rounding down. A multihull doesn't heel much and spill wind so you need to reduce apparent wind.... a 20 knot change in apparent windspeed is a huge change -- even 5 knots could make the critical difference if you were really at the limits.

Fact (not opinion): You really need to understand and use this concept if you're going to sail big multihulls safely in heavy weather... and you also need to reef for the gusts.

Don't learn these lessons the costly way. If you see a squall line approaching you should reef way down or lower sails completely until the initial winds pass and you know how strong a storm you're dealing with. You slow your car for a sharp curve on a wet road, more if it's icy, so why is sailing for specifc conditions and boat characteristics different? 50-knot-plus gusts are not unusual in local storms but can turn almost any multihull over if you don't prepare the boat. Safe operation requires observation, understanding and judgement.
__________________
SailFastTri is online now   Reply With Quote
Old 27-02-2008, 03:10   #83
Senior Cruiser

Cruisers Forum Supporter

Join Date: Dec 2006
Location: Seattle
Boat: Cal 40
Posts: 2,401
Images: 7
Quote:
Originally Posted by SailFastTri View Post
John -- if you haven't had the experience in the Privilege 39 or the Kennex 445 then you weren't pressed to the limits of stability. That's a good thing.

Either of those boats are capable of sailing above 10 knots in a good blow and if you would consider the difference between upwind and downwind may be a change of 20 knots apparent then you should clearly understand the important difference between rounding up and rounding down. A multihull doesn't heel much and spill wind so you need to reduce apparent wind.... a 20 knot change in apparent windspeed is a huge change -- even 5 knots could make the critical difference if you were really at the limits.

Fact (not opinion): You really need to understand and use this concept if you're going to sail big multihulls safely in heavy weather... and you also need to reef for the gusts.

Don't learn these lessons the costly way. If you see a squall line approaching you should reef way down or lower sails completely until the initial winds pass and you know how strong a storm you're dealing with. You slow your car for a sharp curve on a wet road, more if it's icy, so why is sailing for specifc conditions and boat characteristics different? 50-knot-plus gusts are not unusual in local storms but can turn almost any multihull over if you don't prepare the boat. Safe operation requires observation, understanding and judgement.
Yes I'm fairly confident I understand. The apparent wind angles and speeds start getting really interesting when your boat speed is greater than true wind speeds. I sail both my sx18 and 20 at close reaching angles for my best downwind vmg in the right wind conditions. A Tornado polar shows the apparent wind speed can be 1.7 times as great as the true wind on a true wind beam reach.

The chart below I calculated from the polar I linked above. The wind increases less than 10 knots from a run until the angle where the sails should start to luff. Yes if you're pressing the limits while you're running, you're in trouble, yes it would be good to have a mainsail you can reef while going downwind, but as you point out in your next paragraph that would be bad seamanship to have waited that long. What you are not seeing is the jump in apparent windspeed well above true windspeed as you try to get from a high reach to a low reach or vice versa that high performance boats see that is usually associated with the zone of death.

I'm not disagreeing that you should be aware that the apparent wind is going to increase, and prepare for it.

John
Attached Files
File Type: pdf privilege 445 awa aws.pdf (21.8 KB, 207 views)
__________________
cal40john is offline   Reply With Quote
Old 27-02-2008, 03:54   #84
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
Quote:
Originally Posted by cal40john View Post
What you are not seeing is the jump in apparent windspeed well above true windspeed as you try to get from a high reach to a low reach or vice versa that high performance boats see that is usually associated with the zone of death.John
I know it's early and the caffine hasn't fully kicked in yet but I'm puzzled by this. Maximum apparent is on a close reach. How do you calculate this can increase when bearing off?
__________________
Tropic Cat is offline   Reply With Quote
Old 27-02-2008, 05:20   #85
Registered User

Join Date: Feb 2008
Posts: 2,061
Quote:
Originally Posted by rickm505 View Post
I know it's early and the caffine hasn't fully kicked in yet but I'm puzzled by this. Maximum apparent is on a close reach. How do you calculate this can increase when bearing off?
It's not so much an issue of maximum apparent but more an issue of increasing apparent (if overpowered in a gust) by rouding up. Apparent wind increases instantly when you turn from a reach to a close reach, and centrifugal forces from weight aloft also work to lift the windward hull during such a turn, which increases peril if at the edge of stability. This can happen quite fast. If already close-hauled (beating) your best tactic might be to simply ease the sails rather than round up.

If you are even close to beam-reaching or broad reaching you are better off to quickly turn downwind if you have room to do so (beware of the accidental gybe)... centrifugal forces from weight aloft would work to push down the windward hull during such a turn, and once the turn is made the boat would accelerate and apparent wind reduce proportionally to boat speed and direction.
__________________
SailFastTri is online now   Reply With Quote
Old 27-02-2008, 05:30   #86
Registered User

Join Date: Feb 2008
Posts: 2,061
jump in apparent windspeed

Quote:
Originally Posted by cal40john View Post
What you are not seeing is the jump in apparent windspeed well above true windspeed as you try to get from a high reach to a low reach or vice versa that high performance boats see that is usually associated with the zone of death.

I'm not disagreeing that you should be aware that the apparent wind is going to increase, and prepare for it.

John
OK caffeine kicking in -- I'm not disagreeing either. I re-read that and yes that can happen. That's why the turn to bear off dowwind should be done quicky to minimize acceleration and maximize the benefits of centrifugal forces generated from the turn downwind. Also, if close-hauled it may be better to simply ease the sails and reef rather than turn in either direction.
__________________
SailFastTri is online now   Reply With Quote
Old 27-02-2008, 06:12   #87
cruiser

Join Date: Nov 2004
Posts: 4,525
Quote:
Originally Posted by SailFastTri View Post
Also, if close-hauled it may be better to simply ease the sails and reef rather than turn in either direction.

Thanks kind of what I was thinking I'd do rather than abrupt course changes from all my years of single hulling it around.
__________________
ssullivan is offline   Reply With Quote
Old 27-02-2008, 08:47   #88
cruiser

Join Date: Aug 2005
Location: No longer post here
Boat: Catalac Catamaran
Posts: 2,462
Quote:
Originally Posted by SailFastTri View Post
It's not so much an issue of maximum apparent but more an issue of increasing apparent (if overpowered in a gust) .

Wow, are we far apart on this subject. I wonder if this may be boat dependent?

My practice is if in danger of being overpowered, immediately release sheets and head the boat off the wind. No matter what point of sail. The apparent wind is the killer, not true wind. Speaking for my boat, the apparent wind is always...always much forward of true wind. A 50 to 60 degree turn will put me very close to a dead run. In addition the physics favor a turn off the wind as pressure on CE is reduced and the windward hull will in fact drop. Never... never head up under any circumstances as that's a certain receipe for a disaster unless you're in a mono or a tri.

Respectfully
__________________
Tropic Cat is offline   Reply With Quote
Old 27-02-2008, 10:32   #89
Registered User

Join Date: Feb 2008
Posts: 2,061
Bearing off downwind

Quote:
Originally Posted by rickm505 View Post
Wow, are we far apart on this subject. I wonder if this may be boat dependent?

My practice is if in danger of being overpowered, immediately release sheets and head the boat off the wind. No matter what point of sail. The apparent wind is the killer, not true wind. Speaking for my boat, the apparent wind is always...always much forward of true wind. A 50 to 60 degree turn will put me very close to a dead run. In addition the physics favor a turn off the wind as pressure on CE is reduced and the windward hull will in fact drop. Never... never head up under any circumstances as that's a certain receipe for a disaster unless you're in a mono or a tri.

Respectfully
Your ending words "or a tri" are off-base. A tri has similar bahavior to a cat on this issue and as a generality I think tris tend to be a bit higher on the performance curve than cruising cats, so apparent wind is usually further forward in relation to true.

Rick, I think you misunderstood my posts or maybe I didn't express my message clearly because other than that I don't think we're apart at all, as I wrote elsewhere that apparent wind is what it's all about, and that's why one should bear off. Bearing off downwind (quickly) is the preferred tactic when overpowered on a reach. Under no circumstance would I head-up or recommend it -- what I did write is that if you were already close-hauled (pinching close to windward) it might be preferable to simply ease the sheets and reef. That does not mean to head-up because that would increase apparent wind -- it means to hold course.

As for apparent wind being forward of true wind, that's the case for all boats and becomes more true on higher performing boats. However, as true wind rises -- apparent wind diverges to a lessor amount (in degrees) from true wind. That's another discussion, though.

I do the same as you when overpowered (immediately release sheets and head the boat off the wind) but I execute the turn quickly to benefit from the centrifugel forces of the turn, and once the turn is complete I also sheet in the main to reduce effective sail profile and prepare to reef.
__________________
SailFastTri is online now   Reply With Quote
Old 27-02-2008, 14:41   #90
Senior Cruiser
 
Therapy's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: W Florida
Boat: The Jon boat still, plus a 2007 SeaCat.
Posts: 6,894
Images: 4
Quote:
Originally Posted by SailFastTri View Post




As for apparent wind being forward of true wind, that's the case for all boats and becomes more true on higher performing boats. However, as true wind rises -- apparent wind diverges to a lessor amount (in degrees) from true wind. That's another discussion, though.

This discussion is what I have heard about multihulls in the past.
I have been told (and read here) that for the most part the cruiser need not worry about this stuff because one should be a good sailer and reef for gusts, reef early etc etc.
I feel that is foolish.
You see,
With every motorcycle I bought I soon went to parking lots (empty) that were wet, sandy, dry etc. to learn what some of the limits of the bike (and me!) were. Maybe it is just me but I sort of want to know more stuff.

I want know (and practice in controlled circumstances) what to do if it needs to be done.

Tri - do you have reference to diagrams/drawings/charts that describe/show this stuff of apparent wind velocities and how they change etc. with emphasis on a much faster boat ie; a cat? This is for one that has monohull experience (except Hobie's) that wants to get a cruising cat?
__________________

__________________
Therapy is offline   Reply With Quote
Reply

Tags
capsize, multihull

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Volvo Penta 740 DP Lack of Power AJL1275 Engines and Propulsion Systems 12 04-07-2010 09:12
Radio Etiquette and the lack thereof... Rangiroo Marine Electronics 62 03-01-2008 18:24
Recovering from a capsize... shadow Monohull Sailboats 31 21-12-2007 10:28
Capsize ratio lancercr Monohull Sailboats 37 08-02-2007 07:42
Forecasts: Northeast Due for Big Hurricane CaptainK Atlantic & the Caribbean 2 28-03-2006 05:47



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 14:51.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.