Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-01-2013, 21:15   #1
cruiser

Join Date: Dec 2011
Location: Key West FL - Burlington VT
Boat: O'day 32 CC Ketch
Posts: 493
Knocked down 90 degrees

Correct me if I'm wrong. If I plan to sail all over the planet for 40-50 years. At some point it should be expected that a knock down will occur, even with the best weather windows, a storm at sea is unavoidable. So wouldnt the vessel choice for a life at sea be one that pops back up when knocked down 90 degees? Seems like this would be a bigger issue with cruisers, pretty much a deal breaker for me. I cant imagine being in any bad weather and wishing I was in a cat.
__________________

__________________
RabidRabbit is offline   Reply With Quote
Old 25-01-2013, 21:23   #2
Registered User
 
cwyckham's Avatar

Join Date: Apr 2011
Location: Vancouver, BC
Boat: Niagara 35
Posts: 1,870
Re: Knocked down 90 degrees

Having a boring Friday afternoon and decided to go for a little troll, did we?

The vast majority of monohull round the world cruisers never get knocked down. It's a lot harder to knock down a cat. They virtually never go over, and then gross user error can often be blamed. Some very narrow designs may be an exception.

If I could afford it, I'd sell my mono for a sporty cat and cruise in that. Many would. Many do. I would have no issue whatsoever being in bad weather in a cat, and I'd be a hell of a lot more comfortable than in a mono.
__________________

__________________
cwyckham is offline   Reply With Quote
Old 25-01-2013, 21:29   #3
Registered User

Join Date: Nov 2011
Location: Montegut LA.
Boat: Now we need to get her to Louisiana !! she's ours
Posts: 3,421
Re: Knocked down 90 degrees

We have sailed for ver 30 yrs in mono hulls, quit counting NMs years ago at 40,000 + never been knocked down yet !! any amount over normal !! I thik ya got things a little slanted !! shorten sail before ya need to !!
__________________
Bob and Connie
bobconnie is offline   Reply With Quote
Old 25-01-2013, 21:32   #4
Freelance Delivery Skipper..
 
boatman61's Avatar

Community Sponsor
Cruisers Forum Supporter

Join Date: Jan 2010
Location: PORTUGAL
Posts: 20,221
Images: 2
pirate Re: Knocked down 90 degrees

Had a coupla 90* knockdowns over the years... last one was in a 53ftr last year.. F7-8 on the beam and the cross sea's just happened to catch us right... crew injured and my coffee spilled...
bitta damage but cosmetic mainly..
It happens to most voyagers sooner or later if your getting the miles in.. no big deal...
A 360 however is a whole different ball game..
__________________


Born To Be Wild
boatman61 is offline   Reply With Quote
Old 25-01-2013, 21:49   #5
Senior Cruiser
 
DeepFrz's Avatar

Cruisers Forum Supporter

Join Date: Mar 2006
Location: Winnipeg
Boat: None at this time
Posts: 7,930
Re: Knocked down 90 degrees

Quote:
It's a lot harder to knock down a cat. They virtually never go over, and then gross user error can often be blamed.
Do you ever wonder why all production Cats have an escape hatch in the hulls? Have you never seen pictures of the crew of a cat clinging to the underside waiting rescue? I happens more than you realize.
__________________
DeepFrz is online now   Reply With Quote
Old 25-01-2013, 22:00   #6
cruiser

Join Date: Dec 2011
Location: Key West FL - Burlington VT
Boat: O'day 32 CC Ketch
Posts: 493
Re: Knocked down 90 degrees

I'm not trollin for nothin, This is a real issue, if its not what your looking for please feel free to sail right by.

I had come to beleive from my library of 60s & 70s cruising books that the knock down was something that hapened to everyone.
__________________
RabidRabbit is offline   Reply With Quote
Old 25-01-2013, 22:04   #7
Registered User
 
sww914's Avatar

Join Date: May 2009
Location: Punta De Mita
Boat: Vagabond 39 Hull # 1
Posts: 1,842
Re: Knocked down 90 degrees

Quote:
Originally Posted by RabidRabbit View Post
I'm not trollin for nothin, This is a real issue, if its not what your looking for please feel free to sail right by.

I had come to beleive from my library of 60s & 70s cruising books that the knock down was something that happened to everyone.
My boat went through 3 hurricanes in the 70's. With today's weather forecasting there's no need for that anymore. I plan to never get knocked down.
__________________
Steve
http://www.landfallvoyages.com
sww914 is offline   Reply With Quote
Old 25-01-2013, 22:06   #8
Registered User
 
cwyckham's Avatar

Join Date: Apr 2011
Location: Vancouver, BC
Boat: Niagara 35
Posts: 1,870
Re: Knocked down 90 degrees

Quote:
Originally Posted by DeepFrz View Post
Do you ever wonder why all production Cats have an escape hatch in the hulls? Have you never seen pictures of the crew of a cat clinging to the underside waiting rescue? I happens more than you realize.
The escape hatch just makes sense. Of course, it's possible for them to go over and you need to have a hatch. That's sort of like asking if I know why commercial aircraft have rescue slides. They need them. Doesn't mean that I hesitate to fly just because there's a safety slide installed.
__________________
cwyckham is offline   Reply With Quote
Old 25-01-2013, 22:49   #9
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 11,467
Re: Knocked down 90 degrees

RRabbit, I'm not sure exactly what you are looking for!

However virtually any ballasted monohull will rapidly recover from a 90 degree knockdown. There is a parameter called AVS (angle of vanishing stability) which tells you how far over the boat can go and be sure of returning to upright. Most monohulls have AVS values somewhere in the 110-130 degree range. I'm not a naval architect, and the problem is somewhat more complex than as represented here, but that value will give you an idea for any design. Such numbers are always calculated during the design, but are not always shown in the glossy sales brochure. an inquiry to the builder may be necessary.

And to add to the mass of anecdotal evidence: in something over 150,000 miles of blue water and coastal cruising, we have experienced one knockdown to about 90 degrees. I didn't like it. but the boat recovered quickly.

Cheers,

Jim
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is offline   Reply With Quote
Old 25-01-2013, 22:50   #10
Registered User
 
Jimbo485's Avatar

Join Date: May 2010
Location: some ocean down under
Boat: Kelsall Suncat 40
Posts: 1,247
Re: Knocked down 90 degrees

The last time our escape hatch was used involved a female friend who had drunk too much and thought she would lie down in an aft bunk for a while. Suddenly she realised she was going to chuck but she wasn't going to have enough time to get to the deck or the head.

She classified that as an emergency, opened the hatch and spewed her guts out directly into the water.

Very, very lucky we had an emergency hatch!
__________________

Jimbo485 is offline   Reply With Quote
Old 25-01-2013, 23:05   #11
Registered User
 
Jimbo485's Avatar

Join Date: May 2010
Location: some ocean down under
Boat: Kelsall Suncat 40
Posts: 1,247
Re: Knocked down 90 degrees

We had a knock down on our previous boat, a mono. We released the sheets and waited a minute (it was a long minute!) for the water to come off the sails and then she popped right back up immediately. No problem. Apart from the mess down below.
__________________

Jimbo485 is offline   Reply With Quote
Old 25-01-2013, 23:25   #12
Registered User
 
cwyckham's Avatar

Join Date: Apr 2011
Location: Vancouver, BC
Boat: Niagara 35
Posts: 1,870
Re: Knocked down 90 degrees

Looks like my stats suck. From our very small sample size, it looks like the sailors who've been cruising monos for many years and many miles get knocked down as far as 90 degrees more than I thought. It would be really interesting to do a real survey like Beth and Evans put together sometimes.

I haven't heard too many cat owners chime in yet.
__________________
cwyckham is offline   Reply With Quote
Old 25-01-2013, 23:28   #13
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2007
Location: Santa Cruz
Boat: Boatless Again
Posts: 4,334
Re: Knocked down 90 degrees

I spilled my cereal once in over 100,000 ocean miles in monohulls. I've had masts near the water in race boats with spinnakers up, but more like 80 degrees than 90. They popped right back up after we got the spinnaker down. On a cruise we don't press the boat nearly as hard as on a race.
__________________
donradcliffe is online now   Reply With Quote
Old 25-01-2013, 23:42   #14
Senior Cruiser
 
roverhi's Avatar

Cruisers Forum Supporter

Join Date: Aug 2005
Location: Kona, Hawaii, Carlsbad, CA
Boat: 1969 Pearson 35 #108 & 1976 Sabre 28
Posts: 6,006
Send a message via Yahoo to roverhi
Re: Knocked down 90 degrees

The problems with multi-hulls is they reach a point of negative stability or positive stability but upside down. Have a late friend who proved multi's turn turtle. Found his trimaran floating upside down with crew tangled in the running rigging and drowned, no sign of him. Have put the spreaders in the water in the Bay off of SF in a W32. Wind went from a nice sailing breeze to near 40k instantly and subsided back to a nice breeze in minutes. Got a feeling if it had been a multi, would have been able to get a close look at the bottom paint.

That's the reason I'd never sail a cat offshore unless with a full skilled crew that has the quick reactions to dump the main and/or head off when the feces flies. A multi can be blown over without the help of waves. Since I make passages single handed can't rely on a multi to take care of itself. A Mono cannot be rolled except in conjunction with waves, Even then the boat will right itself though probably missing the rig. Still it will be floating upright. A mono will turn up into the wind and dump the wind pressure all by itself in almost all situations. Some people can live with the inverted possibilities of a multi, I can't. Couldn't afford one in any case.
__________________
Peter O.
'Ae'a Pearson 35
roverhi is offline   Reply With Quote
Old 25-01-2013, 23:52   #15
Registered User

Join Date: Dec 2009
Posts: 3,016
Images: 4
I think you should go out and do a knockdown in controlled conditions. It's a confidence builder. When it happens out at sea in an uncontrolled situation you can then say to yourself "Oh, this again. No sweat."

I've had race boats over 90 degrees on several occasions. This boat blew over to 80 degrees cruising on a nice blustery day with all the white sails flying. Demonstrates and failings in ones stowage plan. Would be dangerous on the typical houseboat cruiser what with the basil plants and grills deployed, dinghies flying around, etc.
__________________

__________________
daddle is offline   Reply With Quote
Reply

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




Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 09:28.


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.