Transom hung rudder options - 50 ft catamaran

[mydauphin]

You never said much about the boat, besides 50' cat, or how you are going to use it.
This will determine the answer.

[waikikin]

Originally Posted by sabahcat

No one has mentioned the fact that transom hung rudders stuff up a perfectly good set of swim steps.
Personally, this style of thing is the go if you must have them


In reality, I would prefer a bog standard balanced spade and keep the boards down a touch for rudder protection.

Simple & strong

[oldsailor7]

Clyde Cessna's motto was "Simplicate and add less weight".
Lock Crowther followed this dictum and the results were evidenced in all his designs.
His Buccaneer 24 had a simple transom hung rudder which pivoted up, controlled by two lines leading to plastic jam cleats. Worked just fine.
His Buccaneer 28 had a simple but very effective under slung spade rudder. I never had any problems with this rudder grounding.

[Silver Raven]

Originally Posted by sabahcat

No one has mentioned the fact that transom hung rudders stuff up a perfectly good set of swim steps.
Personally, this style of thing is the go if you must have them


In reality, I would prefer a bog standard balanced spade and keep the boards down a touch for rudder protection.

Saba - why would we want to steer the boat - with good - well designed - retractable rudder blades (as was requested in the original request post) at the cost of a great - wonderful - swim happy transom.

I thought rudders were to steer boats with & swim ladderrs were for swimmers - darn - - must have got something wrong. Please enlighten me as to why I would want to compromise 'good steering' for a swim ladder. beats me.

Please & thanks - ciao, james

[Silver Raven]

Originally Posted by Ismotorsport

Would like to get some insight and thoughts on transom hung rudder options for a 50 ft catamaran. I am considering the following options:

Daggerboard rudder system (farrier style) with longer cassette such as this



Permanent mount (balanced transom hung rudders) such as this


Retractable (balanced style rudders) such as this


I understand that thru hull rudders would be best so no need to explain why.. Looking more for opinions on transom hung rudder options with focus on ease of build and strength and practical use.

Thanks

Gooday bloke - I'm outa-step-here. Big time. Lots of people in here are at contradiction with themselves - ie - - "I understand that thru hull rudders would be best " bla bla - Not so. Far to many boats sport transom-hung rudders for this opinion to be a 'given'.

So as I said & I'm not going to take a backward step just cause others seem to think that - the premis - is a 'given'. There are some great examples that might well fly in the face of such a premis.

I am sure a properly designed rudder blade - correct section - profile - size - shape overall would be far the better idea. Why anyone would expose their rudder(s) to smashing-up - rather than have them - flip-up - - is far beyond my comprehension - ooops chaps.

On this one I'll keep to the size, shape, sections, profile - etc etc that - some of the best yacht designers - went to a whole lot of trouble to design & get right & all you's guy's in the know - can go your way. Ciao, james

[Silver Raven]

Originally Posted by mydauphin

You never said much about the boat, besides 50' cat, or how you are going to use it.
This will determine the answer.

Why - is the water different in your area - does the water change because of how you choose to use it ??? What are your factual basis in design parameters ??? Please - so I can learn - what I really don't understand. ciao, james

[oldsailor7]

Despite James's tendency to rant-----he is quite right.

One can do no better than obtaining the excellent AYRS book No. 79 "Rudder Design for sailing craft".
This book covers the whole subject in detail and is required reading for anyone designing, building or modifying his own boat for optimum performance and convenience. http://www.ayrs.org/ayrslist.htm

[sabahcat]

Originally Posted by Silver Raven

Saba - why would we want to steer the boat - with good - well designed - retractable rudder blades (as was requested in the original request post) at the cost of a great - wonderful - swim happy transom.

I dont know james, why would you?
Personally I'd have bioth, well designed retractable or kick up rudderblades AND wonderful swim happy transoms.

I see no need to sacrifice one over the other

I thought rudders were to steer boats with & swim ladderrs were for swimmers - darn - - must have got something wrong. Please enlighten me as to why I would want to compromise 'good steering' for a swim ladder. beats me.

Please & thanks - ciao, james

Sounds like you have never had experience with both types James, I have and let me tell you there is no comparison between the two.
Both types should steer the vessel with no problem at all but have fun climbing down or up some narrow swim ladder in any sort of slop with groceries in hand vs pulling up beside steps and calmly placing goods on steps before alighting onto a safe platform.

Give me the swim steps and proper balanced spades any day over some rudder system stuck on the transom like some sort of afterthought.

[sabahcat]

Originally Posted by Silver Raven

I am sure a properly designed rudder blade - correct section - profile - size - shape overall would be far the better idea.

Why are you suggesting that a non transom hung rudder would not be properly designed or size/section etc?

[Silver Raven]

Try - - because they -- very simply - are NOT been better designed rudders & center-boards for the last 25 years. Try if you wish to waste time - keeping pace to 40 years ago but - I was there & I have moved on -

WHY don't you. -With great respect for you opinion - - james - - ciao. I'M listening ???

[SPJ yachts]

Have you considered cassette rudders, if your hull design has the W/L beam to accomodate.

[sabahcat]

Originally Posted by Silver Raven

Try - - because they -- very simply - are NOT been better designed rudders & center-boards for the last 25 years. Try if you wish to waste time - keeping pace to 40 years ago but - I was there & I have moved on -

WHY don't you. -With great respect for you opinion - - james - - ciao. I'M listening ???

You've lost me, what are you babbling about?

Are you trying to say that transom hung rudders are the best things ever, regardless and there is no way possible that under-slung rudders could equal or better them?

I suggest you provide some form of evidence to support your claim.

[cavalier mk2]

I'm getting a little lost here too. I fail to understand what the retraction/kick up mechanism has to do with the rudder section. Inboard or outboard rudders can work well, I've used both.

[oldsailor7]

Ditto:

[oldsailor7]

This thread is not quite settled.
Sabahcat said:-
"Are you trying to say that transom hung rudders are the best things ever, regardless and there is no way possible that under-slung rudders could equal or better them?
I suggest you provide some form of evidence to support your claim."

Come on James. What about it.