Balancing the rudder on a trailer sailer

After several requests, I go through the theory and process in balancing the rudder on my RL28 to give a nice light helm requiring a couple of fingers to steer the boat even in heavy conditions. Before the modification the helm was heavy and required considerable force in heavy conditions to turn the boat. A relatively simple modification it could be applied to many trailer sailers which generally have unbalanced rudders. I talk a lot about the theory involved in rudder balance to help explain my my slightly unorthodox method is effective in providing rudder balance and a much improved helm.

[@julesmoto9022]

Wow just what I and a fellow Clubman owner were looking for. We made our wedges yesterday and discovered your video today before we have had the chance to test ours. Great to have confirmation we are on the right track. Thanks heaps :).

[@TRAILERYACHTADVENTURES]

Thanks for the feedback. Way back listening to some clubman owners talking about the concept led me to think about it more and make my modification. Its the easiest way to reduce the tiller pressure on a transom hung rudder. Too much and the rudder will lock over sideways but the right amount and its perfect. Cheers Mark :)

[@blacksheep6888]

Thank you ever so much, I bought an 18 foot aluminium trailer sailer that is missing its rudder, now I know how to make one from your excellent video, vary much appreciated.

[@TRAILERYACHTADVENTURES]

Thanks for the comment. Good luck with building your rudder. The principles are simple enough. Just remember not to put too much of the rudder forward of the rotation line as it will make it unstable if too much. Should not be more than around 18% of the rudders surface area that is in the water. Glad the video has given you some help. Cheers Mark

[@michealhunter1977]

Very informative, thank you for sharing

[@tonywoollcombe1799]

Once again Mark, a stroke of genius....beautifully explained. Thank you and CHEERS Tony W

[@DocLois2010]

Great work Mark, well explained.

[@jbro0671]

Thanks very much generously sharing this Mark. You may just have solved my weather helm problem on my MASRM 720. I’m excited to try this. Wonderful explanation!

[@TRAILERYACHTADVENTURES]

Hi Jonathon, It may or may not solve the weather helm issue, it depends on the cause of the weather helm. It does reduce tiller pressure and the change in the position of the rudder can help reduce weather helm. On my RL28 making the rudder more vertical increases its wetted surface which increases the resistance to slipping sideways a bit more at the stern which counteracts weather helm. I have also increased the headsail and reduced the roach on the mainsail to move the center of pressure of the sails forward a bit which also resists weather helm. The rudder mod is definitely worth a try and it will definitely give you lighter steering. The main thing to watch is you don't push the bottom of the rudder too far forward as said in the video as it will eventually go past the balance point and the rudder will lock in a turn. I suppose that's why its called balancing a rudder. Glad you found the video useful. Cheers Mark

[@cruisinpete7]

Wow Mark, thanks heaps. I know exactly what you are talking about as I experience heavy weather on my RL28. I'm onto it. Many thanks for sharing your RL 28 mods. :-)

[@TRAILERYACHTADVENTURES]

Hi Pete, thanks for the comment. The one thing I would add is that it wont remove weather helm if you experience weather helm in light to moderate winds, that will be a sail/rig balance issue. It will help a bit as the rudder in this mod moves forward moving the center of lateral resistance slightly forward. It will reduce the tiller pressure required to counteract it though very well. There is something in the keel configuration of an rl28 that when the boat is heavily heeled it tends to want to round up. Most boats will do this to varying degrees, it has to do with the center of pressure on the sails and the center of lateral resistance on the keel separating in the horizontal plane that causes the rotation force and weather helm during heavy heeling. Reefing the main early on a standard rl28 rig is the best way to manage it. All boats have their quirks and I still think the rl28 is a great boat. Cheers Mark

[@petercorser1828]

@@TRAILERYACHTADVENTURES She does try to round up sometimes in the gusts, Does the mod make rounding up more likely or just make it easier to keep on course?

[@TRAILERYACHTADVENTURES]

@@petercorser1828 The modification does 2 things. It balances the rudder so even when the boat is trying to round up in gusts the tiller pressure needed counteract it will remain light instead of the extremely heavy tiller you can get in those circumstance. The other thing it does is move the rudder forward and deeper in a similar way to other mods done by rl28 owner who extend the top pintle. This moves the center of lateral resistance marginally aft (the average point that stops the boat sliding sideways) by putting a bit more rudder area in the water. This is only a small effect but theoretically should reduce rounding marginally when well heeled. The forces involved are hard to explain without lots of diagrams. So overall my mod improves things substantially but will not overcome an unbalanced rig. Sailing with an overtight headsail will also increase rounding up. It is all a compromise. I have put a mast head rig on my boat to increase the headsail to the size of the mainsail. This moves the center of pressure of all the sails forward allowing better sail balance which also reduces rounding up. I rarely have rounding up events these days but if the headsail is too tight and I get a strong gust off the wind you can still be rounded up a bit. Cheers Mark

[@RobotRangerGuy]

I think the main reason boats are designed to have weather helm and round up into the wind in heavy gusts is for safety. It is safer for a boat to round up than down, where it could be pinned over in a dangerous broach, throwing everyone overboard etc. Weather helm is good. Too much weather helm is really annoying, hard work and slows you down.

[@coopersrace7277]

Nice explanation Mark. This has been used for many years on aircraft also to lighten the force on the control stick or pedals.

[@TRAILERYACHTADVENTURES]

Yes its not a new concept but one that is often misunderstood. Very useful in aviation just as it is on nearly all keel boats but rarely applied on trailer sailers. It saves on autopilot power and improves the effectiveness of my wind vane steering as well. The place I notice it most is in a heavy cross sea. The tiller would be unbearably heavy when the stern of the boat is hit by a large wave and thrown sideways. The sudden crossflow would put heavy pressure on the tiller where with the balanced rudder it is much more stable and the tiller pressure very manageable. Cheers Mark

[@thesmoo1973]

More of these please

[@sailingcitrinesunset4065]

That's a very interesting concept and my Sunmaid20 has a heavy rudder also. I might experiment with extending the leading edge a bit. Thanks for sharing. Nigel

[@TRAILERYACHTADVENTURES]

Hi Nigel, If the Sunmaid has a swing rudder the same balancing effect can be gained by having the swing rudder swing slightly more forward. On my Southern Cross 23 with a swing rudder I had that system where the rudder could be swung further forward past the rotation line of the pintles. The right amount and the rudder would be magically light and wonderful but too much it would become unstable and want to lock over in a full turn. Its all about keeping the amount forward of the pintles below 20% of the wetted rudder area. Adding more to the front will work too but it increases the total surface area and may change the center of lateral resistance of the boat, might but unlikely on a Sunmaid. Cheers Mark

[@sailingcitrinesunset4065]

@@TRAILERYACHTADVENTURES Ok cheers

[@michaelbirch9265]

Another great idea and well explained. On your previous video about your masthead sail modification you gave me a detailed response to my question. Is there any chance you could draw up some pictures with measurements and maybe some photos and either e.ail them to me or include them in another video please? Keep the video coming, very informative. Cheers

[@TRAILERYACHTADVENTURES]

Hi Michael, Unfortunately I lost the measurements of the 3 new rigging wires when I had a computer crash. Measuring them would be difficult in place especially the forestay that would involve dismantling the furler so those measurements would be when I next replace rigging which is not due for a few years. There were a few different height masts used on RL's so it may or may not apply exactly to your boat. In essence I moved the existing forestay back to the back edge of the anchor well. Added a new forestay from the top of the mast to the anchor bracket at the nose of the boat. Created smaller rear angled spreaders between the main spreaders and the top of the mast. Added 2 new Ubolts next to existing side ubolts and run 2 new rigging wire from the new ubolts through both spreaders to the top of the mast. The adjustable rear stay was left as is. The lower spreaders were extended 50mm by adding some extended ends from Keeley marine so the new and original side wires would be separated by 50mm to these spreaders. Next time I am out sailing I can take photos of all the critical bits I have just described and email them to you. You would need to email me at [e-mail] so I could email them back as I cant attach photos here. Cheers Mark

[@RobotRangerGuy]

Very cunning :)

[@CaptMarkSVAlcina]

Hi Mark, Thanks very much for the information. I just thought the designers would have done that already.

[@TRAILERYACHTADVENTURES]

Hi Mark, Generally considered too complicated to do on a trailer sailer. Classic way is to have the rudder wider at the bottom so the front part is in forward of the pintles. With a dagger board this is very hard to make work although it would be possible on a swing rudder. I suppose the pressures in a small boat are not enough to go to this trouble in designers minds. Many do have quite heavy tiller pressures and especially in heavy conditions. Cheers Mark

[@CaptMarkSVAlcina]

@@TRAILERYACHTADVENTURES hi Mark, thanks for your reply and great information.

[@anar128]

Silly question i have always wanted to ask. What is the blue coloured covering all over your yatcht... for grip? What's it called please?

[@TRAILERYACHTADVENTURES]

No such thing as a silly question! The RL 28's where made with large panels of textured fiberglass for grip. All the parts of the deck colored blue are these textured panels. This is molded into the surface when the boat was built. Old fashioned but very practical and good to walk on especially when wet. Cheers Mark

[@tonywoollcombe1799]

Hi Mark, quick question, I keep reading that it is very difficult to insure a trailer sailer with a pop top. May I ask which insurance company did you use for Halcyon? Thank in anticipation

[@TRAILERYACHTADVENTURES]

Hi Tony, I used GIO for years but then they started asking for annual surveys on the boat and roadworthys on the trailer that was over 30 years old. I changed to Youi for a while but they became expensive and finally with RACV boat insurance who were very competitive and didn't require all the checks each year. That is who I have Neringa insured with now. Of course they may also start getting ridiculous as the boat gets older, we will see but for now they are pretty good and didn't ask about pop tops. All insurers are pretty dubious about moored boats and if the boat is moored I cant help you much there. Cheers Mark