Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 19-11-2017, 11:55   #61
Registered User
 
Cadence's Avatar

Join Date: Dec 2008
Location: SC
Boat: None,build the one shown of glass, had many from 6' to 48'.
Posts: 7,645
Re: Hurricane wind effect on rigging on the hard

Quote:
Originally Posted by hellosailor View Post
a64-
There is inevitably Something Really Stupid Obvious that accounts for baffling problems like "Why should it fail at 200mph when it can take much bigger loads?"
Like the tale you've no doubt heard, that when the Brits found out that the US was testing jet aircraft windshields for bird strikes, by firing chickens out of an air cannon directly at the windshield.
And the Brits complained that the glass was always breaking.
Apparently no one had pointed out, you need to let the handy frozen chickens defrost before firing them. Ooops.

It could be something as simple as hurricane debris hitting the shrouds, causing a severe and basically invisible twist on the mast perhaps? Hurricane "impact resistance" is, after all, normally tested in the US by literally firing a 2x4 at various objects, and finding lareger and heavier objects embedded in walls and trees after the storm is normal, so we know there IS heavy flying debris to be dealt with.

An excellent point about flying who knows what in a boat yard.
__________________

Cadence is offline   Reply With Quote
Old 19-11-2017, 11:57   #62
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 24,105
Re: Hurricane wind effect on rigging on the hard

Quote:
Originally Posted by hellosailor View Post
a64-

There is inevitably Something Really Stupid Obvious that accounts for baffling problems like "Why should it fail at 200mph when it can take much bigger loads?"

Like the tale you've no doubt heard, that when the Brits found out that the US was testing jet aircraft windshields for bird strikes, by firing chickens out of an air cannon directly at the windshield.

And the Brits complained that the glass was always breaking.

Apparently no one had pointed out, you need to let the handy frozen chickens defrost before firing them. Ooops.



It could be something as simple as hurricane debris hitting the shrouds, causing a severe and basically invisible twist on the mast perhaps? Hurricane "impact resistance" is, after all, normally tested in the US by literally firing a 2x4 at various objects, and finding lareger and heavier objects embedded in walls and trees after the storm is normal, so we know there IS heavy flying debris to be dealt with.


That is what I think accounts for most of it, as has been said mast is in compression and if you crinkle it, it will fail much more easily.
__________________

a64pilot is offline   Reply With Quote
Old 20-11-2017, 15:45   #63
Registered User

Join Date: Jun 2016
Location: Jensen Beach, Fl
Boat: O'Day 34
Posts: 180
Re: Hurricane wind effect on rigging on the hard

quote-
There is inevitably Something Really Stupid Obvious that accounts for baffling problems like "Why should it fail at 200mph when it can take much bigger loads?"

Like the tale you've no doubt heard, that when the Brits found out that the US was testing jet aircraft windshields for bird strikes, by firing chickens out of an air cannon directly at the windshield.

And the Brits complained that the glass was always breaking.

Apparently no one had pointed out, you need to let the handy frozen chickens defrost before firing them. Ooops. -end quote

The part about frozen birds is true. Most of my career was spent at a major aircraft engine manufacturer. The bird ingestion test consisted of firing 7-3 lb. pheasants from a helium cannon point blank at >200 mph. This was filmed in slow motion to determine the effects of the birds hitting the fan.
Unfortunately, one of my guys provided the birds, directly out of the deep freeze and lo and behold, the $3M engine failed the ingestion test. And he was not fired.
Too bad that I don't still have a photo of that to post here
Quadrille in JB is offline   Reply With Quote
Old 20-11-2017, 17:09   #64
Marine Service Provider

Join Date: Sep 2012
Location: Virgin Islands
Boat: 1999 Leopard 45, 45 foot cat, 1980 Hunter 33, 33 foot monohull
Posts: 780
Re: Hurricane wind effect on rigging on the hard

First of all, at Nanny Cay, very few cats on the hard lost their rigs. Most of the mono's did, but most also fell over and tangled their rigging. I don't think it's more complicated than that. The windage on the rig may have helped topple the boats. Nanny Cay has facilities to drop rigs. It's just not customary to do so, but they are thinking of changing that and making it a condition of storage.

Mono's in cradles also fell over. And, in Spanish Town, mono's with their keels in pits also went over and broke their keels. Not many cats in the water survived, although mine did with some serious damage. Many cats on land shifted sideways and broke their keels. In the water, of course, they weren't strapped down and many went flying. Even 50 plus feet up in the air. For long distances. I am a catamaran sailor and, for long, have stored my boat, which I live on, in the water. For storms of this strength, I don't think, any more, that storage in the water is viable for a cat. Remember, a Boeing 747 takes off in about 200 mph, so if you could have tethered one, it would have taken flight. Eyewitnesses saw my boat pitch up about 40 degrees, but it settled back down. Everything inside shifted.

Remember, the wind was exceptionally strong. The Department of Disaster Management lost their anemometer at 220 MPH, and thetr were other credible reports up to 300, probably in tornados. The DDM also lost their building and had to evacuate, with some injuries, during the eye.

I hope storms of this force are not the new normal. It was a terror to live through, even ashore.
contrail is offline   Reply With Quote
Old 20-11-2017, 17:37   #65
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 24,105
Re: Hurricane wind effect on rigging on the hard

I can only assume that the rig on a Cat would be stronger than a mono?
A mono will heel or get knocked down so it will shed load so to speak.
A Cat won’t, so I can see how it would be designed right from the beginning to be stronger?
a64pilot is offline   Reply With Quote
Old 20-11-2017, 19:43   #66
Registered User

Join Date: Mar 2015
Location: New Zealand
Boat: Moana 33
Posts: 1,092
Re: Hurricane wind effect on rigging on the hard

Quote:
Originally Posted by hellosailor View Post
...Sacrificial mast, anyone?
On yesterday's news, a monohull north of NZ lost its mast, which took out a large chunk of deck and sank the boat. Lone sailor rescued from liferaft by container ship. Presume some sort of rigging failure, as there was no hurricane here that I'm aware of.
__________________

NevisDog is offline   Reply With Quote
Reply

Tags
hurricane, on the hard, rigging, wind

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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
HURRICANE IRMA'S EFFECT IN BVI'S gts1544 General Sailing Forum 45 20-09-2017 10:27
Effect of Air Temperature on Wind and Reefing? Wotname Seamanship & Boat Handling 15 02-09-2017 07:12
Another hard starting 3GM-30f hard starting issue phantomracer Engines and Propulsion Systems 29 17-05-2017 03:19
Lessons Learned Hurricane Irene- Hurricane Hole Preparation jacob30 Weather | Gear, Reports and Resources 7 21-01-2012 07:51



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 22:27.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2019, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.