Rudder angle.

[Superflid]

What is the "recommended" maximum angle for a rudder to work at? Is there one?
Mine is free to swing about 70 degrees (rough guestimate, boat is 70 miles away) each side of straight ahead.
I've heard talk of too much being of no use as the water flow tends to stall, if that's the case I could fit stops at what should be the limits of useful range.
Single shaft inboard if that helps.

 

[Guest]

Though sometimes it might be useful to have the ability to use the rudder as an emergency brake by applying alternately hard port lock followed by hard starboard lock etc.? eg. when sailing into a berth after engine breakdown...

 

[euroe]

35 degrees ought to be ample. You can also expect some helm assistance when going astern and bearing in mind the effects of a right or left handed prop'.

 

[oldsaltoz]

35 degrees is the normal, keep in mind that when going astern any more then 35 degrees can be all but impossible to hold and may cause damage to your rudder due to high loadings.

Avagoodweekend......

 

[William_H]

My rudder is transon mounted and when it stalls or approaches that point you can hear and if you look over the back you can see the turbulance. This mostly occurs with spin driving hard on a reach and when the boat is leaning a lot such that some of the turbulance is caused by the rudder is trying to lift the stern as well as turn the boat.(or at least straighten it) This tends to occur about 35 degrees as already suggested. However I also occasionally use an outboard and when trun9ing hard ie O/B turned full lock and rudder nearly full lock it is still giving good power near 90 degrees when the boat is rotating in its own length. Now I realise this is not applicable to you however the point is 35degrees stops would not suit my boat.
In fact if it aint broke don't fix it, what is the present problem? olewill

 

[Superflid]

[ QUOTE ]

In fact if it aint broke don't fix it, what is the present problem? olewill

[/ QUOTE ]

No problem really, but I'm just thinking that if I turn the wheel too far I might not be turning the boat as quickly.

35 seems to be the magic number, so thanks to all. Just got to decide if I need to limit the movement. Might try some "sea trials" with temporary stops fitted.

 

[Lakesailor]

Agree with ole will.
You soon find out what you can get away with. Different conditions and boat speeds may effect how well the rudder works. It's always nice to have a bit extra in hand, even if too much rudder slows you down, that could be handy now and then.

 

[Superflid]

Learning to handle the boat might be best then. lol. I know I'll have to put some practice in.
I've driven and ridden most things since the age of........can't remember! Boats are something I'm fairly new to, inboard with shaft I've done about a couple of hours so far!

 

[dmayes]

When you turn the rudder the boat will start to spin on it's keel. (centre of resistance) This means that the flow of water over the rudder will change and you could then turn it further to get a better turn. This will only work when slow manoeuvres are used, just when you need a better turning angle. Try slow speed manoeuvres with only 35 degrees of rudder, then try a bigger rudder angle to see the difference. Don't lose your slow speed turn just to get the correct angle for high speed use, just don't turn the wheel so much. Or fit a rudder angle gauge.

 

[Superflid]

Experience see!

I should be getting some more practice on thursday, will try things out and leave well alone for now at least, probably altogether. Maybe the people who installed my steering knew better than me.....

Thanks again.

 

[peterb]

If you're going to practise (a good thing anyway) then get the boat into a tight turn then look over the side to see the angle at which the water is approaching the rudder. Remember that for maximum rudder force, the rudder will need to be at an angle of 10-15 degrees to the water flow; it's not too difficult to get the water flow angle up to more than 30 degrees, so the rudder needs another 15 on top of that.

But just be careful when going astern. Our old Fulmar could easily throw the hemsman across the cockpit and pin him into a corner if the astern speed was too high.