Movement in rudder blade
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Category: Hints & Tips
Forum Name: 411
Forum Description: 411 Hints and Tips
URL: https://www.myhanse.com/forum_posts.asp?TID=2797
Printed Date: 27 March 2026 at 03:51
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Topic: Movement in rudder blade
Posted By: samba
Subject: Movement in rudder blade
Date Posted: 11 February 2009 at 15:22
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Hello,
I noticed some vibrations in the steering column. When sailing this occurs sometimes and it is just a little vibration. When using the engine I feel it now most of the time when using the engine above 2000 revs.
When I dived under the boat to feel the rudder blade, I noticed that there is a little movement in the rudder blade.
Has anyone got any suggetion what I can do?
I am now looking for a place to get the boat out of the water.
Thanks,
Michiel
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Replies:
Posted By: Gregor
Date Posted: 11 February 2009 at 15:32
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Hello Michiel,
I assume you have a steering wheel. Is it the blade you feel, or the rudder stock that is moving? There is a topic about the rudder (called Emilia's rudder) that might be of help. It tells you much about bearings. A company called Jefa also posts on this form. They have in depth knowledge on rudders. If you can not figure out what's on, maybe they can be of any help. Gregor ------------- Uisge Beatha Currently sailing Dehler 36 JV (2002) Previous boat: Hanse 311 #80 http://www.uisge-beatha.eu" rel="nofollow - http://www.uisge-beatha.eu |
Posted By: samba
Date Posted: 11 February 2009 at 21:30
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We do have a steering wheel.
I can't move the rudder stock when in the aft locker.
When I dive under the boat I can move the rudder blade when I try this at the very bottum end of the blade. I am not quit sure if this is the blade or the stock. I will check to see if I can find out.
Cheers,
Michiel
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Posted By: panos
Date Posted: 11 February 2009 at 21:39
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Hi, Some vibration during very fast sailing (planning in the face of a wave for example) is normal.Strong vibrations during fast motoring ,specially during acceleration are also normal. The first are caused by turbulence on the trailing edge of the rudder blade, when the flow reaches a critical speed and can be reduced by fairing the blade. The second are caused by cavitation (steam bubbles in the water) caused by overloading the propeller. If the blade or propeller surface is "dirty" the vibrations appear earlier. I suggest though to be on the safe side to check it the first time the boat is out of the water. If the rudder moves relative to the shaft then this could be dangerous and IMHO should be corrected. If the shaft has a little clearance in the bearings then this is normal wear.In my boat I would tolerate a movement of the tip of the rudder of 15 to 20mm. ------------- Panos Hanse 630e - selling her - |
Posted By: samba
Date Posted: 11 February 2009 at 22:01
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Hi Panos,
I get the vibrations when motoring above 2000 revs. So no real high revs in my opinion.
You do give (as always) a very good tip: The blades of the propellor are very dirty. I will clean them tomorrow. In the past the vibrations came above 2400 revs.
I did change the standard propellor for a 3 blade max prop propellor.
The tip of the blade does not move more then the 15-20 mm, so I presume that is normal then.
Thanks,
Michiel
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Posted By: samba
Date Posted: 17 February 2009 at 02:49
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Hi Panos,
I cleaned up the propellor and although the fish liked it very much, it made no real difference. The next port where I canhaul out the boat, I will do so since there is nothing I can see / do right now.
Cheers,
Michiel
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Posted By: samba
Date Posted: 05 April 2009 at 03:38
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Hi All,
I have put the orginal propellor back on the boat. However the problem still exists but it is less since the fixed two blade has I presume less turbulence.
The yard also checked the rudder from the outside but there was just a little bit of movement. I also had some riggers check the kwadrant and this was all tensioned properly.
One thing that I did find out is that the engine can now run at higher revs (3200 revs). With the maxprop it could just about reach 3000.
When back in Holland I will put the maxprop back on and change the pitch of the prop. I will also remove the rudder to check the bearings. I don't want to do that now since I know of one other boat that had big problem after they worked on his rudder in Las Palmas.
Cheers,
Michiel
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Posted By: gshannon
Date Posted: 06 April 2009 at 03:25
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Turbulence from the prop is one possible cause of vibration in the rudder, however Hanse rudders are usually quite far from the prop which reduces the effect. Does it happen under sail? If so it could be the trailing edge of the rudder. The worst shape is a rounded back edge. Better is a sharp edge but subject to damage. Even better is a squared off flat of 3 to 6mm. Best of all (I know this from tank testing) is the least likely shape you would think of, which is a flat with one edge radiused off, the other sharp. The explanatory theory is complex, but it works. It doesn't matter which side is which. ------------- Grahame Tangleberry 371-092 aviadesign.com |
Posted By: panos
Date Posted: 06 April 2009 at 12:23
Hi, When I was racing seriously, we followed your suggestion. But we always selected one side. It depends if the boat races in the Northern or Southern hemisphere. Obviously Coriolis forces make a small difference in the flow of water around the two sides of the rudder, so you want the faster side to be straight. The difference though could be so small that only Grand Prix boats (TP52,AC etc) are affected. But of course the subject caused long discussions in the club evenings and everybody followed the champions. All this just to pass the time, of course, since no Hanse boat will gain any advantage following my theories. ------------- Panos Hanse 630e - selling her - |
gshannon wrote:Posted By: gshannon
Date Posted: 06 April 2009 at 15:34
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Hi Panos, That is amusing, and reminds me of an old story told me by Ted Brewer. He and Bill Luders entered a boat of their own design in the 5.5 Meter World's. That class has a minimum beam requirement, and when the boat was measured it fell short of the minimum by a few millimeters. Ted and Bill used putty to put bumps at the measurement points in order to not be disqualified. It would have ended then, had it not been that they WON the World Championship. The next year ALL the top boats had bumps, although nobody except Bill and Ted knew their purpose! ------------- Grahame Tangleberry 371-092 aviadesign.com |
Posted By: Peter-Blake
Date Posted: 06 April 2009 at 16:28
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great story grahame ------------- Blake 370 
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Posted By: Peter-Blake
Date Posted: 09 April 2009 at 14:28
 Found this in the www
It is going about the shape of the end of a rudder or keel.
"relative vibration amplitude"
So - let us start to shape our rudders....
http://www.abload.de/img/rudder-d5a6xfy.jpg - ------------- Blake 370
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Posted By: panos
Date Posted: 09 April 2009 at 19:04
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Hi, The practical problem with shape 3,4 and 5 is that since the rudder consists of two halves, the pointed spot is exactly at the join ,making it VERYYYY sensitive. Thats why shapes 6,7 and 8 are used. ------------- Panos Hanse 630e - selling her - |
Posted By: Peter-Blake
Date Posted: 09 April 2009 at 19:10
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Yes, my previous boat had shape 6 and worked perfect .
But it is interesting how diffrent the vibration amplitude is ------------- Blake 370
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Posted By: samba
Date Posted: 10 April 2009 at 19:06
Hello Grahame,
Normally I don't feel it when sailing. I do feel it a little bit when sailing fast downwind and waves coming from behind.
Cheers,
Michiel
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Posted By: gshannon
Date Posted: 13 April 2009 at 18:15
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Indications are that the rudder trailing edge shape is at least partly to blame. See previous posts. An unbalanced propeller can also contribute to this, but I would expect it to be felt through the whole boat as well as the rudder. ------------- Grahame Tangleberry 371-092 aviadesign.com |
Posted By: samba
Date Posted: 03 May 2009 at 03:12
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Hello, The steering system now makes some sqeeuking noise. I found out that it is the rudder stock just very slight touching the white plastic (outer bearing). You can see this when you open up the emercengy steering opening. I have had someone take a look at and there is no structural damage. Does anyone know if the 411 has selfaligning bearings. So this might go away when I go back sailing. I will go out sailing on monday again. Thanks, Michiel
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Posted By: bougainville
Date Posted: 03 May 2009 at 08:23
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hi,
may be you can find something usefull on http://www.jefa.com - www.jefa.com .
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Posted By: samba
Date Posted: 09 May 2011 at 20:21
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Hi all,
An update from my side. This winter all the bearings were replaced. Not really replaced but I just found out that the yachting service put in oversized bearing rollers as suggested by Jefa. Unfortunetely the problem is not away and has to be redone. It could be that there is some wear and tear at the rudder stick. I will keep you posted Cheers, Michiel |
Posted By: samba
Date Posted: 12 May 2011 at 19:20
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Next update: The jacht service has been in contact with Jefa and the solution is going to put an galvenised aluminium sleave around the rudder stock and put a completely new bearing specifically for that size.
Hopefully the problem will be solved in 3 weeks time Cheers, Michiel |
Posted By: km311
Date Posted: 27 February 2012 at 12:01
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Hi Michael, Recently my 311 has a strong vibration from the rudder in the range between 5 and 6 knots. Today I and the marina staffs including a engineer were on board to investigate the problem. After test cruising, the boat again sit on the cradle, the engineer tapped it on the both side of the rudder by the stainless stick, listened to the taps, and told me that the inside of the left side of the rudder was likely to peel from the ribs, because the taps of the both sides sounds differently each other. As a result, the rudder lost strength and became flexible, to cause the vibration. It seems to be neccesary to rebuild or remake the rudder. I am very sorry.... The engineer said the structure of the rudder of Hanse generallly weak even if it is new. I tried to bend a lot of rudders including my 311 and other sailing boats in the marina, and I found that my rudder is clearly softer than any other boats. |
Posted By: samba
Date Posted: 27 February 2012 at 20:29
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Hi km311, Thanks for the info. At my boat the barings were replaced solving 90% of the problems. There was a lot of movement in the rudder pole. Interesting to know it can also be the rudder blase itself. Next time when the boat is out of the water I will check that as well. Thanks for the info Cheers, Michiel ------------- Samba - Hanse 411 - Bruinisse |
Posted By: Ronmeul
Date Posted: 02 August 2014 at 23:40
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There is a simple way to adjust the rudder. On the rudder shaft just below deck there is an adjustment ring. Is is black and it has three inbus bolts, i believe arounf M6. Beforre loosening them attach a line to the shaft where the emergency rudde can be placed. Make sure there is som pressure on the line but not too much. Loosen the three bolts. After that turn up the pressure on the line to pull the rudder up and fasten the three bolts. The rudder wil have far less movement after, at least mine did.. Ron ------------- Ronald |