Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 28-08-2009, 20:01   #16
Registered User
 
beau's Avatar

Join Date: Dec 2006
Location: Brisbane Australia
Posts: 757
Images: 1
sorry that link, is www.austal.com
state of the art shipbuilding
beau is offline   Reply With Quote
Old 28-08-2009, 20:04   #17
Registered User

Join Date: Aug 2009
Location: Land-locked at the moment :(
Posts: 189
le sigh,

None of the three earthrace hulls have flat bottoms. Check this video link at 1:15.



Also, I never said your boat actually did plane. I said it is likely that it is generating lift and raising the stern.

Please explain triflection.
Event_Horizon is offline   Reply With Quote
Old 28-08-2009, 20:32   #18
Registered User
 
cat man do's Avatar

Join Date: Aug 2006
Location: Brisbane Australia [until the boats launched]
Boat: 50ft powercat, light,long and low powered
Posts: 4,409
Images: 36
A good article from the late Malcolm Tennant on hull shapes

Catamaran Comparisons by Malcolm Tennant

Talks about the "earthrace" Craig Loomes hulls and Gold Coast Catamarans.
__________________
"Money can't buy you happiness but it can buy you a yacht large enough to pull up right alongside it"...............David Lee Roth
Long Distance Motorboat Cruising – It Is Possible on a Small Budget
cat man do is offline   Reply With Quote
Old 28-08-2009, 20:37   #19
Registered User
 
cat man do's Avatar

Join Date: Aug 2006
Location: Brisbane Australia [until the boats launched]
Boat: 50ft powercat, light,long and low powered
Posts: 4,409
Images: 36
Quote:
Originally Posted by beau View Post
sorry that link, is www.austal.com
state of the art shipbuilding
Very much like White Rabbit
__________________
"Money can't buy you happiness but it can buy you a yacht large enough to pull up right alongside it"...............David Lee Roth
Long Distance Motorboat Cruising – It Is Possible on a Small Budget
cat man do is offline   Reply With Quote
Old 28-08-2009, 21:01   #20
Registered User
 
44'cruisingcat's Avatar

Join Date: Sep 2006
Posts: 9,399
Images: 69
Woods Designs Sailing Catamarans
44'cruisingcat is offline   Reply With Quote
Old 30-08-2009, 20:32   #21
Registered User
 
beau's Avatar

Join Date: Dec 2006
Location: Brisbane Australia
Posts: 757
Images: 1
further information.
Built in Aluminium
39ft X 8 ft will fit inside a 40 ft shipping container
Oceanic lateen sail for low cost downwind cruising.
Motors 2 X 30 hp Honda outboards to be upgraded to 2x90 hp for 20 knots plus.
Narrow entry non planing/ fast displacement hull, shallow draft (9 inches)
Attached Thumbnails
Click image for larger version

Name:	beaujest09.jpg
Views:	162
Size:	27.0 KB
ID:	9630   Click image for larger version

Name:	beaujestplan.jpg
Views:	153
Size:	275.6 KB
ID:	9631  

beau is offline   Reply With Quote
Old 30-08-2009, 21:15   #22
Registered User

Join Date: Aug 2009
Location: Land-locked at the moment :(
Posts: 189
how much weight are the outriggers supporting on flat water?
Event_Horizon is offline   Reply With Quote
Old 30-08-2009, 23:50   #23
Registered User
 
beau's Avatar

Join Date: Dec 2006
Location: Brisbane Australia
Posts: 757
Images: 1
I have never checked the actual % of weight supported by the outriggers but unlike sailing trimarans both outriggers are in the water at all times.(bow down) (necessary)

There is at all times a NEGATIVE angle of attack, ie. the bottom of the boat is flat but tilted forward and the bow is always the deepest part of the boat in the water when underway. (1-1.5 ft, deep)
The wide stern just touches the water.
This does create a degree of bow steering, which was an initial concern with the prototypes (Five 15 ft prototypes have been built)
This has also been a problem with some of the multhull fast displacement ferries (from personal experience)
This is where I found that using a Trimaran configuration was preferable to a mono or catamaran design plus the addition of a decent rudder or stern keel.(daggerboard)

Aft of midway along the hull, under way, if you throw ash (or other floating material) on the water the ash is sucked under the hull.

Initially there is a stern wake but once the boat reaches speed, the stern wave flattens out, and there is little or no wake with little or no interference with other boats in the vicinity.

Driving straight into the waves (90 degress) is its best point underway, there is little or no lifting to waves (in moderate seas) and no hobby horsing which is very common with fine hulled catamarans.
beau is offline   Reply With Quote
Old 31-08-2009, 00:23   #24
Registered User

Join Date: Aug 2009
Location: Land-locked at the moment :(
Posts: 189
Well, discovering how much the outriggers are carrying isnt too hard (since they are not curved). Measure the draft, multiply that by the surface area of the bottom, multiply again by the weight of water per unit by whatever unit area you're using (make sure you are consistant). I'm interested to know this.
Event_Horizon is offline   Reply With Quote
Reply

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
Has anyone used Dri Diver or Hull Super Scrub for hull cleaning??? avazquez Product or Service Reviews & Evaluations 2 06-06-2020 05:49
Garmin 'In-Hull' vs 'Thru-Hull' Transducers La Bras D'or Navigation 24 23-09-2009 07:26
Hull and Rigging Design anjou Monohull Sailboats 4 10-07-2009 14:24
410: Lagoon 410 Hull Design Drawing Ian Pearce Lagoon Catamarans 0 08-04-2009 06:39
Best 38' Hull Design - Least Pounding? 3Eagles Multihull Sailboats 32 30-12-2008 06:45

Advertise Here


All times are GMT -7. The time now is 05:16.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2023, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.