Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 28-10-2013, 12:33   #1
Registered User
 
zboss's Avatar

Join Date: Sep 2011
Location: On a boat
Boat: Cabo Rico 38
Posts: 3,427
Shipping Containers on Radar

Do floating shipping containers show up on radar?

What about other floaty things that can cause damage?
__________________

__________________
zboss is online now   Reply With Quote
Old 28-10-2013, 12:37   #2
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: 12,387
Re: Shipping Containers on Radar

Very unlikely. From what I know, most shipping containers are not floating high in the water but just barely awash. To get a reliable radar return you have to have something sticking up out of the water to bounce the signal.

Same for any other objects in the water.
__________________

__________________
The water is always bluer on the other side of the ocean.
skipmac is offline   Reply With Quote
Old 28-10-2013, 12:40   #3
Registered User
 
martinjrichter's Avatar

Join Date: Dec 2010
Posts: 71
Re: Shipping Containers on Radar

The problem with floating containers is they are low in the water and therefore don't have much of a return to the radar. If the radar where above the container( ie an aircract or satelite) there would be a much better chance of a return, although the is some problems from "ground effect" to overcome.
__________________
martinjrichter is offline   Reply With Quote
Old 28-10-2013, 12:52   #4
Registered User

Join Date: Mar 2013
Location: Annapolis, MD
Boat: Sail any boats from 28 to 60 ft
Posts: 530
Re: Shipping Containers on Radar

Using an underwater sonar system or a depth sounder mounted horizontally 2 ft below the water line.
__________________
rockDAWG is offline   Reply With Quote
Old 28-10-2013, 12:58   #5
Registered User

Join Date: Oct 2013
Posts: 2
Re: Shipping Containers on Radar

I also heard that infra-red is being used and can pick up shipping containers. The container fraction that is on top of the water will pick up ambient and solar heat. However the detection distance is probably limited to a couple of 100 ft. May be enough to warn you of a problem and better than nothing. Not sure how this would be compared to sonar.
__________________
cruisehope is offline   Reply With Quote
Old 28-10-2013, 13:48   #6
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: 11,466
Re: Shipping Containers on Radar

Look, the problem with all these detection systems is signal to noise ratio. And all three (radar, sonar and IR) have real bad situations detecting a low floating object. Under the right circumstances they will all show the container, but those circumstances are not common, so what you see is a lot of noise with occasional blips of signal rising above the noise level. If an attentive watchstander is peering at the display 24/7 a useful warning might result, but if one depends on in-built alarms in the instruments the chance of detection is low.

Thus, for the typical short handed cruising boat, reliable detection of a floating container is dependant upon daylight and an alert lookout. In other situations the low statistical chance of hitting one is all that protects you. Fortunately, this seems to be pretty effective!

Cheers,

JIm
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is offline   Reply With Quote
Old 28-10-2013, 13:56   #7
Registered User

Join Date: May 2009
Location: Massachusetts
Boat: 40' Silverton Aftcabin with twin Crusaders
Posts: 1,590
Re: Shipping Containers on Radar

Do many of the loose containers make it to shore? How big a problem do they present to cruisers?
__________________
foggysail is offline   Reply With Quote
Old 28-10-2013, 14:08   #8
Registered User

Join Date: Oct 2013
Posts: 2
Re: Shipping Containers on Radar

Jim-You are absolutely correct. A good lookout is about the only effective means of spotting a container. However, after the new movie All is Lost, my wife may want more.
__________________
cruisehope is offline   Reply With Quote
Old 28-10-2013, 14:43   #9
Senior Cruiser

Cruisers Forum Supporter

Join Date: Aug 2009
Location: between the devil and the deep blue sea
Boat: a sailing boat
Posts: 17,314
Re: Shipping Containers on Radar

But if you place a small octa reflector on it, you may as well spot it on your radar.

b.
__________________
barnakiel is offline   Reply With Quote
Old 28-10-2013, 14:49   #10
Registered User
 
DumnMad's Avatar

Join Date: Mar 2012
Location: Nelson NZ; boat in Brisbane
Boat: 45ft Ketch
Posts: 1,248
Re: Shipping Containers on Radar

A lot more whales out there than containers.
I know people who've hit whales but nobody who has hit containers. (Maybe containers are more fatal.)
__________________
DumnMad is offline   Reply With Quote
Old 28-10-2013, 15:27   #11
Registered User

Join Date: Dec 2009
Location: Pickering Ontario
Boat: 1995 hunter 430
Posts: 330
Re: Shipping Containers on Radar

Ok for real................has anyone seen one of these floating containers......I dont mean you know somebody or you read it somewhere............has anyone on this forum seen a loose container floating around....
__________________
Navicula is offline   Reply With Quote
Old 28-10-2013, 15:31   #12
Nearly an old salt
 
goboatingnow's Avatar

Cruisers Forum Supporter

Join Date: Jun 2009
Posts: 13,649
Images: 3
Me , no , whales yes


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
Reply

Tags
radar, shipping

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 23:29.


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.