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13-09-2017, 13:56
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#1
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Registered User
Join Date: Sep 2017
Posts: 24
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one rudder catamaran
ANY ONE , WITH A CENTRAL RUDDER ONLY ON A 40 FT PLUS CATAMARAN???????????
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13-09-2017, 14:18
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#2
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Senior Cruiser
Join Date: Nov 2013
Location: Port Moresby,Papua New Guinea
Boat: FP Belize Maestro 43 and OPBs
Posts: 12,888
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Re: one rudder catamaran
Doubt it. Why would you do that?
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13-09-2017, 14:24
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#3
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Registered User
Join Date: Mar 2011
Location: Panschwitz, Germany
Boat: Woods Mira 35 Catamaran
Posts: 4,234
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Re: one rudder catamaran
Malcolm Tennant did that back in the 80ies on some of his smaller boats.
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13-09-2017, 14:34
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#4
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Registered User
Join Date: Mar 2015
Location: Currently cruising in SE Asia
Boat: Catana 47 hull no 1 ex Leopard 40 (2009) & Crownline 250CR
Posts: 383
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Re: one rudder catamaran
There is a 45 foot cat in mozambique (wooden built) with a pod in the middle housing a single yanmar Diesel engine and centre single rudder and dual centreboards
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13-09-2017, 14:42
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#5
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Registered User
Join Date: Sep 2017
Posts: 24
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Re: one rudder catamaran
thanks for the info,,, modern cat???
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13-09-2017, 14:45
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#6
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Registered User
Join Date: Mar 2015
Location: Currently cruising in SE Asia
Boat: Catana 47 hull no 1 ex Leopard 40 (2009) & Crownline 250CR
Posts: 383
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Re: one rudder catamaran
No it's been here for 17 years now. Originally it had two outboards mounted in the rear of the hulls that could be raised up manually from the inside when not in use. I heard it was a woods design but not sure. The rudder is also adjustable up and down so you can beach the boat
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14-09-2017, 05:27
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#7
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Registered User
Join Date: Nov 2007
Boat: TRT 1200
Posts: 7,268
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Re: one rudder catamaran
Dereck Kelsall designed quite a few cats with central rudder.
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14-09-2017, 06:06
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#8
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Registered User
Join Date: Jun 2014
Location: Up the mast, looking for clean wind.
Boat: Currently Shopping, & Heavily in LUST!
Posts: 5,629
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Re: one rudder catamaran
Quote:
Originally Posted by smj
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Aye. There was one for sale in Mexico a few years back. It was quite well traveled as I recall.
__________________
The Uncommon Thing, The Hard Thing, The Important Thing (in Life): Making Promises to Yourself, And Keeping Them.
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14-09-2017, 06:11
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#9
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Registered User
Join Date: Nov 2007
Boat: TRT 1200
Posts: 7,268
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Re: one rudder catamaran
The central rudder has the same disadvantage as a central outboard, it tends to catch weeds which greatly decreases boat speed. Maybe having the rudder hung of a pod which extends below the waterline will deflect the weeds?
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14-09-2017, 06:45
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#10
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Registered User
Join Date: Jun 2014
Location: Up the mast, looking for clean wind.
Boat: Currently Shopping, & Heavily in LUST!
Posts: 5,629
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Re: one rudder catamaran
Quote:
Originally Posted by smj
The central rudder has the same disadvantage as a central outboard, it tends to catch weeds which greatly decreases boat speed. Maybe having the rudder hung of a pod which extends below the waterline will deflect the weeds?
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There's a few more disadvantages. Specifically, there's naught in front of it to protect it from striking objects, like hulls & mini keels, or daggerboards. So it's much more vulnerable even to things like heavy kelp, or crab pot floats. Let alone substantial floating debris like logs, etc.
Also surface piercing rudders (those not underneath of hulls) are only about half as effective, as there's no end plate effect to enhance their efficacy. Although some transom hung rudders, such as on Class 40 monohulls, & other high speed solo boats, have end plate built onto the rudders themselves, so as to somewhat mitigate this loss in efficacy. And a much shorter distance in between it's bearings/pintles & gudgeons.
And with a central rudder on a catamaran, the rudder has a much longer cantilever distance. So that the hardware connecting it to the boat is under a lot more load than that found on transom hung, or rudders underneath of hulls. Cantilever distance meaning lever arm. Since the rudder has to span a couple of feet of air, along with the portion of the blade which is in the water. Thus making it much longer than say one which is transom hung, with attendent increased loads.
__________________
The Uncommon Thing, The Hard Thing, The Important Thing (in Life): Making Promises to Yourself, And Keeping Them.
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14-09-2017, 09:04
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#11
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Registered User
Join Date: Nov 2008
Location: Round Bay, Severn River
Boat: Formerly Pearson 28-1, now just a sailing dinghy
Posts: 1,332
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Re: one rudder catamaran
What are the advantages? Just a more direct tiller to rudder linkage?
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14-09-2017, 11:23
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#12
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Registered User
Join Date: Nov 2007
Location: Cruising in the SUN! Now hauled out in Malta for the winter.
Boat: 37' Oldenziel cat
Posts: 461
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Re: one rudder catamaran
I have a 11m cat with a single central lifting rudder which, when fully lowered, is about 1.3m deep. The rudder is also prebalanced. From a sailing perspective I cannot detect any negatives when comparing it to a two rudder set up. I have now sailed 9,000+ miles and never caught anything on the rudder - had a pod of delphins though in the Bay of Biscay playing their "touch the rudder game" with their snout!
__________________
Roger
Catamaran "Burnout"
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14-09-2017, 11:34
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#13
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Registered User
Join Date: Dec 2006
Location: Cruising
Boat: Privilege 39 Catamaran, Exit Only
Posts: 2,723
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Re: one rudder catamaran
It would need to be a fairly large central rudder to be effective.
I know of one catamaran that lost a rudder in the Gulf of Mexico, and then during their circumnavigation they lost a rudder when approaching South Africa. Both times that they lost one of their rudders, they immediately knew that something was wrong because their sailboat overpowered the remaining rudder.
I personally like having two rudders, but I have no illusions that if I lose one of them, our catamaran will be less responsive and harder to control in certain wind conditions and sea state.
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14-09-2017, 12:20
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#14
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Registered User
Join Date: Sep 2017
Posts: 24
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Re: one rudder catamaran
Quote:
Originally Posted by Franziska
Malcolm Tennant did that back in the 80ies on some of his smaller boats.
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THANKS FOR THE REPLY,,,, YOUR OPINION????
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14-09-2017, 12:21
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#15
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Registered User
Join Date: Sep 2017
Posts: 24
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Re: one rudder catamaran
Quote:
Originally Posted by smj
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THANKS FOR THE PHOTO,,,,
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