Twin Rudders

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I like the Southerly but have heard various storeys over ineffective rudders until boat gets to a speed (no prop wash over rudder). Bad in marinas

Now I appreciate that Ex and current owners of twin rudder boats will be biased but are there any sailors out there who have switched between single and twin rudder set ups that would like to comment on marina manouvrebility
 
I have a friend with a Southerly 110 and going astern in a marina can be 'interesting'... he has a bow thruster and insists it's money well spent. I had an Etap21i with twin rudders and you just have to get used to giving a burst of power to get some way on pretty sharpish before you get any useful steerage.
 
I hired a Bavari 45 Cruiser this year which has twin rudders and my own yacht is a Rival 41C with a single rudder. I also have experience of plenty of yachts with large, effective, spade rudders.

The only issue I found was in marinas where the twin rudders were poor at low boat speeds e.g. reversing out a berth into a narrow fairway. Going forward was as one would expect. I took three attempts to get her out of one berth. The trick is to get her helm over earlier than normal. Okay that was without the bow thruster. With the bow thruster: easy peesy. My conclusion is that twin rudder yachts, such as the Bavaria, benefit from a bow thruster if she is likely to be berthed in a tight space regularly.

When reefed down and underpowered, in a slop, the rudders also didn't grip well compared to large spade rudders in a similar situation. When well healed no issues that I was aware of.
 
My Jeanneau Sun ODyssey 35 has a lift keel and twin rudders.

Because the keel plate goes up into an 8 foot long keel with wings, that acts like a long keel.

I find that a quick burst of a lot of throttle to get the boat moving backwards,then knock it into neutral, and allow the boat to gather a bit of speed in a straight line backwards, then throw the helm hard over. That way, you have water flow over the rudders, and they will act.
I found the just reversing with the rudders hard over from stand still did very little for a long time.
Aggresive use of throttle gets you nowhere, unlike with a spade rudder in front of the prop.
Gently Gently.

It is a downside to the design, but more than made up for when taking the ground, or creeping round in 1.1m of water.
 
Lived with a Southerly 110 for 6 years now - yes, forget what you did before as it is quite different in marina situations! Even coming alongside and using a midship cleat whilst making life easier, you do not get the propwash across the rudder to hold you at a nice angle to the pontoon.

Bow thruster essential (expect people to pop their heads up when they hear it as it seems to indicate some 'event' may be about to happen!)

Going astern is almost like in a long keeled boat due to both the skeg and twin rudders. As mentioned, keep the rudders in the central position until you have some way on - then it works, albeit in a limited fashion.

Going ahead, get a reasonable turn of speed, helm hard over and into reverse halfway through the turn and you can virtually turn within the boats length. I found practice was the key - try it in the winter months when the marina is usually quite empty.

I was told by another owner that reversing into a berth was 'easier' than ahead as you can see where you are steering and also use the bow thruster to turn you as well.
 
DipperToo said:
I was told by another owner that reversing into a berth was 'easier' than ahead as you can see where you are steering and also use the bow thruster to turn you as well.
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We haven't got a bow thruster, but we have got twin rudders on our lift keel Feeling 32. Reversing into a berth is well-nigh impossible unless you can get a good run-up (impossible in most marina situations, and it doesn't always work anyway!). Going forward is OK but you don't get the advantage of prop-wash over the rudder for slow-speed turns, since the prop is between the rudders. On balance, twin rudders are a pain for slow speed manoeuvring and for reversing. Practice helps, though (7 years with this boat now) and so would a bow thruster, especially in a bigger boat.
 
Twin rudders are a get-out from having a lard-arsed design to accomodate big aft cabins !

The idea of drying out on twin rudders & lift keel makes my toes curl, I've not seen any strongly built splayed twin rudders which look like taking the loads of grounding or going in and out of mud.

As for drying out on a wing keel with twin rudders, this can only appeal to designers and owners with very little imagination who think they'll be drying out aided by a spirit level on a billiard table !

There's also the snag of 'tracking' adjustment to keep the rudders aligned and bushes / bearings maintained.

Guess what ?! My Anderson 22's deep spade rudder has never lost grip yet, including in surf.

Twin rudders on a monohull are an invention of the devil; quite possibly a devil from another planet. :rolleyes:
 
Seajet said:
Twin rudders are a get-out from having a lard-arsed design to accomodate big aft cabins !

The idea of drying out on twin rudders & lift keel makes my toes curl, I've not seen any strongly built splayed twin rudders which look like taking the loads of grounding or going in and out of mud.

As for drying out on a wing keel with twin rudders, this can only appeal to designers and owners with very little imagination who think they'll be drying out aided by a spirit level on a billiard table !

There's also the snag of 'tracking' adjustment to keep the rudders aligned and bushes / bearings maintained.

Guess what ?! My Anderson 22's deep spade rudder has never lost grip yet, including in surf.

Twin rudders on a monohull are an invention of the devil; quite possibly a devil from another planet. :rolleyes:
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You speak from a place where you excrete, and obviously have no experience of the design which you make yourself look foolish at guffawing. Which is a shame, as I think you could, possibly have sensible things to say, given your background.

Getting excited about the level of interest in Anderson 22s again?
 
FullCircle said:
You speak from a place where you excrete, and obviously have no experience of the design which you make yourself look foolish at guffawing. Which is a shame, as I think you could, possibly have sensible things to say, given your background.

Getting excited about the level of interest in Anderson 22s again?
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Full Circle,

I speak from experience, but ta for the backhand compliments !

Would you care to enlighten me re any twin rudders safe to dry out ( pounded on hard sand or going in and out of mud not 'getting away with it' ) please ?
 
For the record, our Feeling has twin rudders not for drying out on, but to reduce the draft. When she dries out, the rudders do not touch the ground - she sits on her cast iron ballast plate. I suspect Southerlies and Ovnis do something similar.
 
Yes, Jeanneau SO32s with centreplate do the same thing. Rudders don't touch the sand.

But what do we know compared with the wealth of experience from Langstone?
 
Seajet,

No, not a wing keel. There is a ballast plate with two fat long shallow bilge keels, between which the centreplate pivots.

Here she is on the beach at Bembridge. Very stable.
 
The only twin rudder I have used was the Spring 25.Probably 500 hours.

The springs' prop was a fair way ahead of the rudders. Very true that there is no useful propwash when stationary, but in a tight turn the inside rudder is now in the propwash, and the boat will circle in not much more (if any) than its' own length. As with most sailing boats, reversing needs at least half a Knot before steering, and don't use much rudder angle until at a few Kts.

Upwind - much less likely to get ventilation.

Downwind - utterly fantastic.

Sorry Seajet but on a sand/mud/shingle shore/bank, they sit upright upright very safely. I must have done it a dozen times, mostly on purpose. Best stern to the shore because it sits back on the shorter rudders.

You wouldn't do it in inclement weather, like many other types.
 
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Seajet said:
Full Circle,

I speak from experience, but ta for the backhand compliments !

Would you care to enlighten me re any twin rudders safe to dry out ( pounded on hard sand or going in and out of mud not 'getting away with it' ) please ?
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You really do need to get out more! There are plenty of boats (including FCs) with twin rudders that are designed to dry out.

Twin rudders are a good solution to particular issues related to designing shallow draft hulls where either speed or accommodation needs dictate a wide stern.

Clearly many people are very happy with such designs as can be seen by their popularity and the long waiting list to buy, for example, one of the Southerlys that have this feature.
 
Tranona,

I don't recall a high performance racing dinghy with twin rudders, and with 3 keels and two rudders I might wonder about wetted area drag; my 'wonder-boat' dries out upright twice a day on soft mud but if people are happy then who am I to argue ?!
 
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1 Keel, 2 centerplates and 2 rudders ...

I wouldn't want to dry one out - but they have no problem with wetted area drag ...

Who mentioned High performance racing dinghy anyway? - If you need twin rudders or even bilge keels on one of them then you really are sailing it wrong!

I assume your design skills and marine knowledge is top notch - perhaps you could give us a list of boats you've designed and what purpose they were designed for?

Had it ever occurred to you that there is usually more than one solution to a given "problem"?
 
Seajet said:
Tranona,

I don't recall a high performance racing dinghy with twin rudders, and with 3 keels and two rudders I might wonder about wetted area drag; my 'wonder-boat' dries out upright twice a day on soft mud but if people are happy then who am I to argue ?!
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Since when are we talking about "high performance racing dinghies" and since when does everything have to compare with what works on them? Twin rudders are common in REALLY high performance ocean racing boats, small sports cruisers and substantial cruising boats where shallow draft is part of the owner's requirements. Pretty well accepted design feature.

As I said, you need to get out a bit more and understand that different people have different requirements and therefore different solutions are appropriate. Just because they do not fit in with your preconceived ideas does not make them invalid for others.

Your constant, unsupported sniping at everything you don't like or don't understand is getting a bit wearing.
 
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