Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 11-08-2013, 18:55   #136
Registered User
 
transmitterdan's Avatar

Join Date: Oct 2011
Boat: Valiant 42
Posts: 4,024
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Quote:
Originally Posted by goboatingnow View Post
I agree , I reduce sail at night , I was merely commenting that hitting a container at 5 knots or 7 knots ain't going to make a lot of difference

Da d
Actually it likely will make a lot of difference. The energy available to a collision is proportional to the square of the speed times the mass of the vessel. At 7 knots the kinetic energy is almost twice the energy available at 5 knots. If I had to hit something I would a lot rather do it at 5 knots than 7.
__________________

__________________
transmitterdan is offline   Reply With Quote
Old 11-08-2013, 19:08   #137
֍֎֍֎֍֎֍֎֍֎

Cruisers Forum Supporter

Join Date: Apr 2006
Posts: 13,051
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

"Divers have to add air to stop sinking. There is nothing like that in a container. "
You're missing the point. Once trimmed to hover at a certain depth, they stay and hover.
If you think a wave washing over a container will always compress it enough to "change" it and sink it, consider a rubber duck, or a Styrofoam cup. they'll float forever, even after repeated waves wash over them. You need to permanently compress the air spaces in order to affect the buoyancy. Will that happen to a container? Eventually, usually. And then there's the reefer cube of taco chips that did wash up in California, from the Pacific islands. Rubber ducks, sneakers from the pacrim...Sure, the containers often sink. Except for the unknown percent that float for thousands of miles.
Trying to hypothesize about the specific levels of ten thousand containers without actually having hard numbers as to how each behaves and what the containers are filled with? Doesn't matter if you hit the one that is just awash for a week or two.

Like deadheads floating in any logging area, which also endure for far longer than your theory would allow.
__________________

__________________
hellosailor is offline   Reply With Quote
Old 11-08-2013, 19:08   #138
Registered User
 
neilpride's Avatar

Join Date: Jul 2009
Location: in the world
Boat: csy 44 tall rig.
Posts: 3,099
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

As far i know, refrigerated containers are waterproof and watertight.
__________________
neilpride is offline   Reply With Quote
Old 11-08-2013, 19:52   #139
cruiser

Join Date: Aug 2011
Location: Tampa Bay area
Boat: Hunter 31'
Posts: 5,731
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Quote:
Originally Posted by Mr B View Post
And if they hadnt cheated with the Bulkheads, It would not have sunk either,

And the rivets. Turned out they also used substandard rivets holding the outer shell together, so it all fell apart easier.
__________________
Rakuflames is offline   Reply With Quote
Old 11-08-2013, 21:04   #140
Senior Cruiser

Cruisers Forum Supporter

Join Date: Mar 2006
Posts: 1,594
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Quickly transfer your stuff to the floating container. Set off EPIRB. And WAIT..
__________________
Randy

Cape Dory 25D Seraph
rtbates is offline   Reply With Quote
Old 12-08-2013, 00:21   #141
Registered User
 
Andy73's Avatar

Join Date: Feb 2013
Posts: 229
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Has anyone produced a sailboat with a steel rib for the cutwater edge? Or even for the keel in general?

I did a quick google but didn't see anything.
__________________
Andy73 is offline   Reply With Quote
Old 12-08-2013, 01:05   #142
Registered User

Join Date: Aug 2011
Location: Melbourne Australia
Boat: Paper Tiger 14 foot, Gemini 105MC 34 foot Catamaran Hull no 825
Posts: 1,616
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

There are quite a few boats with a brass or steel or iron leading edge, running down under the keel,

If that is what you mean,
__________________
Mr B is offline   Reply With Quote
Old 12-08-2013, 06:03   #143
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

I dont beleive a conventional steel yacht made to normal leisure yacht plate thickness would survive a container strike. Ive seen quite a lot if steel boat damage and the welds usually fails and the seam opens.

Dave
__________________
Check out my new blog on smart boat technology, networking and gadgets for the connected sailor! - http://smartboats.tumblr.com
goboatingnow is offline   Reply With Quote
Old 12-08-2013, 07:10   #144
Registered User
 
Group9's Avatar

Join Date: Sep 2010
Posts: 1,599
Images: 7
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Quote:
Originally Posted by goboatingnow View Post
I agree , I reduce sail at night , I was merely commenting that hitting a container at 5 knots or 7 knots ain't going to make a lot of difference

Da d
http://www.ajdesigner.com/phpenergyk...y_equation.php

Plug your boat weight in with 5 versus 7 knots and see how much the joules increase. I think you will be surprised.
__________________
Group9 is offline   Reply With Quote
Old 12-08-2013, 07:31   #145
Registered User

Join Date: Aug 2011
Location: Melbourne Australia
Boat: Paper Tiger 14 foot, Gemini 105MC 34 foot Catamaran Hull no 825
Posts: 1,616
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Quote:
Originally Posted by goboatingnow View Post
I dont beleive a conventional steel yacht made to normal leisure yacht plate thickness would survive a container strike. Ive seen quite a lot if steel boat damage and the welds usually fails and the seam opens.

Dave
There is a hell of a difference in hitting a floating object and some thing solid,
__________________
Mr B is offline   Reply With Quote
Old 12-08-2013, 07:49   #146
cat herder, extreme blacksheep
 
zeehag's Avatar

Cruisers Forum Supporter

Join Date: Jul 2008
Location: furycame alley , tropics, mexico for now
Boat: 1976 FORMOSA yankee clipper 41
Posts: 17,772
Images: 56
Send a message via Yahoo to zeehag Send a message via Skype™ to zeehag
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

worst case scenario is dying before you can have the chance to go out to find what you would do if that container jumped out suddenly in front of your boat deliberately to sink you.....
zeehag is online now   Reply With Quote
Old 12-08-2013, 08:14   #147
Registered User
 
Oceanride007's Avatar

Join Date: Jun 2013
Location: Boat in Whitsundays, heading south.
Boat: Custom Perry Passport 41, steel
Posts: 339
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

I think the odds are pretty low, based on my experience working on a container vessel, reefer containers are stored low so that the engineers can access them to do refrig work. Usually the containers lost are up high, ordinarily those containers unless filled with low permeable cargo (balloons) would sink readily. Once we lost a reefer (refrig container) (stowed on main deck) we reported it as a navigation hazard. But realistically that would sink within 5 Hours. The storm that caused it, well unlikely a yacht would choose to be there.
Think containers get blamed unfairly for yacht mishaps. Still, personally, I would be more comfortable with either metal hull or collision bulk head.
__________________
Oceanride007 is offline   Reply With Quote
Old 12-08-2013, 08:24   #148
Senior Cruiser
 
skipmac's Avatar

Cruisers Forum Supporter

Join Date: Oct 2007
Location: 29 49.16 N 82 25.82 W
Boat: Pearson 422
Posts: 12,381
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Quote:
Originally Posted by Mr B View Post
There is a hell of a difference in hitting a floating object and some thing solid,
Problem is a container is pretty solid. Very rough calculations a 20' container has a volume of about 10,000 gallons, a 40' container double that.

Even if the container is 80% full of cargo that leaves c. 2000 gallons of water to fill a 20' container or about 8 MT. Add the weight of the container (2-3 MT) and the cargo (up to 25 MT) at a min you will be running into a 12-15 MT object. Max could be over 30 MT. That much weight will be the same as hitting something very solid.
__________________
The water is always bluer on the other side of the ocean.
skipmac is online now   Reply With Quote
Old 12-08-2013, 08:45   #149
Registered User
 
SmartMove's Avatar

Join Date: Aug 2011
Location: Cruising the Eastern Caribbean
Boat: Beneteau 473
Posts: 779
Images: 1
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Quote:
Originally Posted by rtbates View Post
Quickly transfer your stuff to the floating container. Set off EPIRB. And WAIT..
+1
__________________
Time is a companion that goes with us on a journey. It reminds us to cherish each moment, because it will never come again. What we leave behind is not as important as how we have lived. JEAN LUC PICARD, Captain of the Starship Enterprise
SmartMove is offline   Reply With Quote
Old 12-08-2013, 09:41   #150
Moderator
 
HappyMdRSailor's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: North Mississippi
Boat: 48 Wauquiez Pilot Saloon-C22 Chrysler Sunpiper- 19 Potter-Preparing to cruise w/my girl
Posts: 5,980
Re: Worst Case Scenario: Hitting A Sunken Container - What To Do!??

Quote:
Originally Posted by boatman61 View Post
They do... and they can be sailed and docked submerged... see 'Pirates of the Caribbean'...
I have been practicing my " nonchalant stepping onto the dock from a submerged hull" move for years now... I hope I never need it... But if I ever do, I hope there is a crowd to see it! (and hand me a beverage)
__________________

__________________
In the harsh marine environment, something is always in need of repair...

Mai Tai's fix everything...
HappyMdRSailor 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 13:30.


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.