Jump to content


Recommended Posts

A lot of extra drag, weight and cost....

930s are one of the most controllable boats around. So narrow the rudder always has plenty or grip.

The boats are not wide enough to get the windward rudder out so you are dragging 2 of them around all the time.

Sorry but I just don't see any gain going with 2 on a Ross 930 and as willow said, it would look hideous.


In fact twin rudders in general are a pain and involve constant tweaking with the toe angle. I have made a guide for our one for different speeds and heel angles. When you get it wrong you know about it

Link to post
Share on other sites
Guest Ketchup

There's no doubt about all that Booboo, I thought the same myself initially....


... but what if the the drag, weight etc is the same values and we forgot about the visual appearance. What would be the down side?


An up side could be even better control?

Link to post
Share on other sites

I have a blank canvas so anything can go. Doing 1 or 2 wouldn't be that much different in work to make. Two would be better from a structural point of view, as it would the safety regs. They would be lower load and one would be the required spare.


Agree 2 would look a little silly but then the skipper already does and he doesn't really care nor should looks affect a potential performance thing. They do look a tad silly on the Dickson.


Drag can be got around with flick up boards...but possibly at the risk of reliability back there maybe and having to flick/deflick when doing inshore sailing, that could be a arse.


2 tillers or 1, again just as easy to do.


I did have a play yesterday and while we are a tip truck we do go better when on our feet so playing the angles and dangles and I'm tending to agree me bum is just not big enough to make 2 any better than one.


The canting thing is interesting. A quick play showed that if I could swing only 13-14 degrees it would make a lot of difference to blade length. I reckon I could shorten it nearly 500mm with the resulting less everything that would bring. But reliability comes into play again.  I'll have another play with that today and see where it takes me.


Now is the time to suss these things. I have a blank canvas and are willing to have a crack of different if it makes sense. We didn't get Open 60's by not playing with new ideas.

Link to post
Share on other sites

What about a canting rudder we did one on the back of a Reactor 25 in the dark old days.

How was it set up or how would you set one up... Mr engineering dude ;)

Link to post
Share on other sites
Guest Ketchup

Why even have a rudder?


Go windsurfer style ;-)


Or... a "two cartridge" rudder box with a "upwind rudder" and a "down wind" rudder. Just slide one up and one down.


Or... a rudder box with two angled boxes and two blades that slide one up and the other down depending on what tack you are on.


With the two separate rudders hung on the transom corners you could have a easy arrangement which pulls up the windward blade (like the AC boats) so you have full control, with less drag.

Link to post
Share on other sites

Agree there really isn't a big problem but the questions do have to be asked.


I have asked questions of every single thing on the boat no matter what the size and what it does, if it's there it's been sussed, so not to do it of the rudder and possible options would be silly. By doing so I have managed to save weight, make things stronger, make them work smoother, make them easier to use and lots of good stuff. I am quite surprised how many small changes I've made that won't be visible to most who have a suss but do contribute to a better to use boat. Sure none have been targeted at faster but all have been targeted to be both eaiser to use and more reliable...which at the end of the day will make her faster to some degree. There has been tweaks and allowances made for the speed targeted changes that will come later but at the moment going hard on those would be about the same as putting a V10 Viper motor into a old Fiat 500, fun for the punters to watch the carnage but otherwise totally pointless.


If ya want to know how anal some of the sussing has been how's this. I wanted a sink that wouldn't vomit it's contents when sailing so I went looking for the ultimate one. In each place any close offering was them loaded with the dozen stubbies I took with me, much to the amusement of staff and customers, to ensure when we lean over they all don't fly out. To do that took a week and I went into 20 odd places. But do I have the perfect sink? Oh Yes.


I'm working on the hinges for my engine room doors. Made some demos then imported some goodies from the EU and are about to make the ones that will be fitted to the boat. So far those 2 hinges have taken easily 40 hours odd so far .......... bit they will be so sexy you will want to rub yourself on them. But to be fair I started on std piano hinge which then evolved into carbon ones from the US until I though I could do better and have since developed one I've, or anyone else I've spoken to, never seen anything similar so it is quite possible I have developed something completely new.


Only the cutting edge is good enough for my 30yo family cruiser.  :D :D

Link to post
Share on other sites

Bet he wouldn't.


Yep, 100% agree.


In my experience, which has been mostly round the cans, the tidiest simplest boats usually perform best.


Less distractions, and less things to go wrong.


But I think twin rudders on a 930 would look cool. You could even put some awesome not-yet-tried system in, which could lift the redundant blade, controlled by twisting the tiller extension. Or a horizontal foil between the two blades for those fast downhills. Go the whole hog, T foil on the keel as well.

Link to post
Share on other sites
Guest Ketchup

It astounds me that people write off idea/s based on a theory in their mind that based on Assumption or no experience of the concept!


How do you now the pros and cons of any of these ideas until you have tried them, modified them and tried them again?


What has KM got to lose in building a twin rudder design of the same weight (or less) with less wetted surface area and drag (one blade up in some /most situations) and with the benefit of maybe better control and less drag.


How can people say that because there is no issue to fix that this new idea will not actually expose one or many vices with the old single rudder system.


People have poo pooed designs and concepts that have later been proven to be winners.


I cannot see these ideas being any slower or less reliable (unless the design/build is piss poor) but I can see some good advantages.


It not about complicating the boat but trying ideas for evaluation or improvement.

  • Upvote 1
Link to post
Share on other sites

Dunno if that was meant to be directed at me or not.

Far be it from me to stifle any ideas, I come from development classes as well as one designs.


I was half serious with my foil idea. Granted, probably not much use on KMM's boat, but could actually work on a long range cruiser. Think of the extra drag you could create by angling said foil downward, say 15deg. Could help slow the boat quite a bit in a big following sea. Like an inbuilt drogue of sorts. Could also dampen pitching when beating into nasty stuff.


Probably work pretty well on a foiling R or something

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...