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Tiller/Rudder pressure


Richardcn

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Hi all

 

As a newbie and having just returned from a week on a hire boat I have a question regarding what might be considered 'normal' with regards to tiller pressure whilst cruising. Just as a little background, the last time we were on a narrowboat, before last week, was about 10 years ago so I cannot use that as a comparison (that is, I can't remember ?). I do have an engineering background so I can understand the principals of these things, that said, of Narrowboats (or any boats) I know only what I have learned whilst searching for a narrowboat of our own this year (and failing so far)!

 

The 'problem' was this, whilst cruising we had to provide a constant pressure on the tiller in one direction whilst going in a straight (ish) line, the boat was always trying to turn to starboard. I spoke to one of the engineers by phone after our first full day's cruising to discuss whether there might be an issue, having checked the prop and the rudder beforehand. They were very helpful but could not identify a problem so we lived with it for the week (and got used to it). However, this 'trait' of the boat did not really allow for relaxed cruising as the higher the revs the more the pressure that was required to maintain tiller/rudder position. As part of the engineers suggested checks I noticed that the Swan Neck and the Rudder were not perfectly aligned, the part of the rudder that I could see was slightly offset to port. My questions are:

 

1. Is this a normal 'quirk' of some narrowboats?

2. What is the likely cause?

 

We didn't let it spoil the trip and as we had reported it (and as we knew no better) we learned to live with it but being an engineer and hoping to get a boat of our own sometime soon I would like to know what to expect in this regard.

 

Any advice is gratefully received.

 

Richard

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1. Is this a normal 'quirk' of some narrowboats?

 

 

Only if they have a problem or operator error.

 

2. What is the likely cause?

 

 

Rudder out of line with the tiller.

 

It has been damaged ie, reversed into something that didn't move.

 

To much power in shallow water.

 

and probably a few more. smile.png

 

Mine does it when the prop is fouled or I get to close to the shallows avoiding boats coming the other way.

Edited by bottle
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Interesting, We had the same problem on a hire boat this year, it needed constant pressure at all times when moving, the boat would try and go to starboard at all times, I have hired several boats in the past and never had this problem to such an extent so it must have been the boat. The boat was an Alvechurch one called Herring Gull, and interestingly the only other time I hired from Alvechurch we had the same problem allbeit to a lesser extent. (On a boat called Knot which they have since sold)

 

I must admit we found it a nuisance but not enough to cause too much bother, and I did assume that it was rudder damage. In fact the whole boat was pretty battered and tired externally and didn't show much sign of regular maintainance. I would be interested to know from the OP which company you hired your boat from.

 

The only solution I found was to let the tiller push against my right hip as it was too tough to hold it in place by hand for long periods, although I was aware this meant I was stanting within the arc of the tiller which is not the safest place to be. We found it as much of a problem doing a modest but not fast speed on the Severn as we did on the narrow canals so I don't think it was due to excessive revs or lack of depth.

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"Rudder out of line with the tiller"

 

As the tiller appeared not to be self-centering would a misalignment just mean that you would need to hold the tiller in a slightly different position to achieve a correct and steady rudder position or is there more to it than that?

 

"To much power in shallow water"

 

It was noticeably worse in shallow water but present at all rpm's, speeds and depths to one degree or another.

 

Edited because the quote thingy didn't work as expected!

Edited by Richardcn
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Rudder out of line with the tiller.

 

 

I disagree. This doesn't create a bias causing the boat to steer to one side when the tiller is let go and left to centre itself, or not in this case.

 

Both my boats have a very slight bias to one side, i.e. on letting go of the tiller it tends to settle at an angle of about 5 degrees away from centre and both boats correspondingly steer slightly towards the bank instead of going ahead straightly. (Is that a word?)b

 

On the REGINALD the need to push the tiller slightly but constantly in order to maintain a straight ahead course is only really noticable on long straights but it eventually gets a little wearing. I suspect it is actually the effect of prop walk.

 

MtB

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Interesting, We had the same problem on a hire boat this year, it needed constant pressure at all times when moving, the boat would try and go to starboard at all times, I have hired several boats in the past and never had this problem to such an extent so it must have been the boat. The boat was an Alvechurch one called Herring Gull, and interestingly the only other time I hired from Alvechurch we had the same problem allbeit to a lesser extent. (On a boat called Knot which they have since sold)

 

I must admit we found it a nuisance but not enough to cause too much bother, and I did assume that it was rudder damage. In fact the whole boat was pretty battered and tired externally and didn't show much sign of regular maintainance. I would be interested to know from the OP which company you hired your boat from.

 

The only solution I found was to let the tiller push against my right hip as it was too tough to hold it in place by hand for long periods, although I was aware this meant I was stanting within the arc of the tiller which is not the safest place to be. We found it as much of a problem doing a modest but not fast speed on the Severn as we did on the narrow canals so I don't think it was due to excessive revs or lack of depth.

I am loathe to mention names as I don't wish to give bad rep in my ignorance but I may change that view as I understand better. However, I can say that it was not the same boat (or not the same boat name)!

 

I too used the 'hip solution' but also being aware of the risks we mainly took turns and swapped arms, although 'the missus' (as I can now officially call her) could only comfortably steer right-handed. This, I'm sure, did take its toll on us but it's hard to judge how much given all the locking that we did. It was the ease with which other boaters seemed to be steering (with feet, draped arms, small of the back etc) that made we wonder, and my engineers head of course!

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I disagree. This doesn't create a bias causing the boat to steer to one side when the tiller is let go and left to centre itself, or not in this case.

 

Both my boats have a very slight bias to one side, i.e. on letting go of the tiller it tends to settle at an angle of about 5 degrees away from centre and both boats correspondingly steer slightly towards the bank instead of going ahead straightly. (Is that a word?)b

 

On the REGINALD the need to push the tiller slightly but constantly in order to maintain a straight ahead course is only really noticable on long straights but it eventually gets a little wearing. I suspect it is actually the effect of prop walk.

 

MtB

I'm with Mike on this one, my boat also likes the bank and as Mike did, I put it down to prop effect. The problem ( I dont' see it as such) is not a major issue and I can steer with draped arm, small of the back, or foot as required.

Phil

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I am loathe to mention names as I don't wish to give bad rep in my ignorance but I may change that view as I understand better. However, I can say that it was not the same boat (or not the same boat name)!

 

I too used the 'hip solution' but also being aware of the risks we mainly took turns and swapped arms, although 'the missus' (as I can now officially call her) could only comfortably steer right-handed. This, I'm sure, did take its toll on us but it's hard to judge how much given all the locking that we did. It was the ease with which other boaters seemed to be steering (with feet, draped arms, small of the back etc) that made we wonder, and my engineers head of course!

I can understand your reluctance to name names but I thought so much had been said about this hire company in another topic

 

http://www.canalworld.net/forums/index.php?showtopic=66700&hl=

 

That anything I said would not be of significance. Just to balance my comments the boat we hired from Alvechurch was really nice and comfortable inside and we had a great trip. It takes more than a bent rudder or scratched paintwork to detract from my enjoymnet when I am lucky enough to be afloat!

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On my previous boat there was quite strong and continuous pressure to go off to the side, and I am fairly sure it was prop walk, at MtB says. In this case it was caused by having one of those high efficiency props, that give great control and speed at low revs, but push the back of the boat sideways when under higher revs. On shallow water it was worse.

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At tickover when passing moored boats etc the effect was negligible but noticeable, at cruising speed/walking pace (circa 1300 rpm) you had to position yourself so that you could apply a solid opposite force at all times (unless turning right ). That went against the whole idea of relaxed cruising on the canal especially when going for 2 or 3 hours at a time. At burst throttle revs one needed to have got used to this quirk in order to maintain control of the tiller! We did learn to live with it but that was mainly because of why we were there in the first place and through not knowing any better.

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Interesting topic.

 

Today, we took some friends out to The Folly at Napton. (Good food) The man of the couple is a mechanical engineer btw. When we take folks out it is a hands on day, steering, lock work etc.

 

With the guy steering we went for a little way at tick over to enable him to get used to pushing left to go right and so forth. As I increased the revs I noticed he apparently developed a tendency to let the bow drift off to the right. He did ask was his steering at fault? I then twigged this was possibly due to prop walk. As I have helmed the boat so often I suppose I am used to it and subconsciously make adjustments. In the past in our marina I have played around and not touching the tiller the boat drifts to the right going forwards and to the left going backwards.

 

David your boat is ok. smile.png

 

ETA Mike perhaps it's a "Banana Boat?"

 

Edited by Ray T
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Please forgive my lack of technical terms. There was a posting on here a few weeks back about reducing the size of the rudder plate which is in front of the rudder axis. It was something to do with adjusting the ratio of leading and trailing areas. My boat is a real pig and I find it really tiring fighting with the tiller all day. I guess the plate forward of the axis gets pushed around by the water from the prop whereas the part of the rudder which is trailing helps to reduce this effect.

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Please forgive my lack of technical terms. There was a posting on here a few weeks back about reducing the size of the rudder plate which is in front of the rudder axis. It was something to do with adjusting the ratio of leading and trailing areas. My boat is a real pig and I find it really tiring fighting with the tiller all day. I guess the plate forward of the axis gets pushed around by the water from the prop whereas the part of the rudder which is trailing helps to reduce this effect.

 

I think that part of the rudder is called the balance blade. I had the same problem as you when I first bought the boat. Very tiring to steer straight and needing a LOT of concentration all the time or the rudder would slam over to one side or the other.

 

I fixed it when the boat first came out for blacking by getting the yard to cut a 2" vertical strip from the leading edge of the rudder, and in order to maintain rudder area I asked them to weld the offcut back onto the trailing edge of the rudder.

 

WHAT a transformation!!!!!!!!!!! The boat is a joy to steer now and one has to actually lean quite hard on the tiller to push it over to full deflection when the boat is in gear. I thoroughly recommend this modification.

 

 

MtB

Edited by Mike the Boilerman
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Sounds like a 'symmetry' problem with the hull to me.

 

I bet you weren't the first to complain with it being that bad!

 

 

MtB

I'm not so sure Mike. Thinking about it now, whenever I was approaching a mooring or entering a lock I would take the engine out of gear and use larger (than normal) tiller movements using the flow of water over the rudder from the boat's forward motion to make minor direction changes. I didn't notice any problem then, although with the speed being so low at these times and with no tiller judder from prop wash it may have been harder to detect. When giving quick bursts of the throttle to correct my inadequecies as a steerer (during the same scenarios) however, the effect on the tiller was quite marked. I'd tend to go with rudder misalignment myself if I had to guess, although whether that was by poor design, poor build or hirer damage (that latter being most likely I suppose) I wouldn't like to say.

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I think that part of the rudder is called the balance blade. I had the same problem as you when I first bought the boat. Very tiring to steer straight and needing a LOT of concentration all the time or the rudder would slam over to one side or the other.

 

I fixed it when the boat first came out for blacking by getting the yard to cut a 2" vertical strip from the leading edge of the rudder, and in order to maintain rudder area I asked them to weld the offcut back onto the trailing edge of the rudder.

 

WHAT a transformation!!!!!!!!!!! The boat is a joy to steer now and one has to actually lean quite hard on the tiller to push it over to full deflection when the boat is in gear. I thoroughly recommend this modification.

 

 

MtB

With an alteration such as this is there a possibility that, when going astern, the larger aft section of the rudder would cause the tiller to snap to full deflection whenever a rudder input was applied (ie in any position other than central to the flow of water over it)? Your description of the effort needed for full deflection when going ahead makes me imagine how there must be a balance to be achieved in this sort of situation. Just a thought for anybody considering the same .

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I recently took my half brother (15) and sister (11) our for a cruise. They both took to the helm relatively well. What was interesting were the questions and observations from their young minds, the younger one in particular.

 

One things she said was: "Why don't you just have a mark for where the tiller needs to go so you are going straight forward? Then you could just point it there and you wouldn't have to look where you are going." I had to give several answers to this before she understood, the one that made the penny drop was wind.

 

I, like Phil, am able to steer with draped arm, foot, small of back etc. the boat does pull to port slightly; I have always assumed propwalk. One interesting feature, when sitting on the roof on the port side of the hatch (trad stern), easily within reach of the throttle, it is a bit of a lean to get to the tiller in the centre. Shame, because otherwise this is a very comfortable position. A foot can be used, but also a mooring pin can have its ring slipped over the tiller end, and provide a very useful aid! I believe such things are common on small sailing boats...

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I believe such things are common on small sailing boats...

 

Tiller extension

 

105110-tiller-extension-sail-boat.jpg

 

When I used to race Fireball racing dinghy's these were necessary to allow the helm to "hike out" to help counterbalance the boat healing.

Apart from running before the wind sailing dinghy helms tend to sit up wind on the boat to allow for better visibility and also to be able to watch the "set" of the sails.

 

102_large.jpg?1397126651

 

benfinncarbon.jpg

 

 

More robust ones are also available for offshore yachts:

 

 

SA-Tiller-Ladder-Extension-RF3116.png

 

I personally feel they would be more a hindrance than a help on a Narrowboat.

Edited by Ray T
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It would appear that there is no clear cut answer as to what is 'the norm' with regards to my original query, which is not that surprising given the diversity of boats out there. I will contact the hire company to follow up on my original observation/complaint to them, if only in the hope that they take a look at the next opportunity and resolve any fault that they find so that future hirers have an easier time at the tiller.

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I am only really guessing since to make any really valid assessment you'd need to try to steer the offending boat but as a suggestion is the rudder likely to be slightly off-line to the prop? Is the skeg out of alignment? I don't really accept the 'prop wash' theory since the faster the boat goes the less effect you get from prop wash so it is only really noticeable when the boat is moving really slowly. My own boat has a tiller/rudder that naturally goes to the dead centre setting even if I were to let it go altogether whilst on the cut, it seems from what the OP was saying if he released the tiller the boat would immediately steer with a bias, something is clearly wrong. Since we all have prop-wash to a greater or lesser degree my thought is that it must be something else, and a bent skeg seems to me a possibility. This would mean that the prop thrust would always be adversely deflected by the rudder, requiring the helm to continuously try to correct it, hence the continuous (and tiring) steering to one side.

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It can easily be fixed when out of water, by a trim tab, saw some that had two cuts in the trailing edge, making a smaller tab that was bent one way to trim the forces. Is sometimes called Flettner trim tab when adjustable

 

One other solution will be a gurney flap http://en.wikipedia.org/wiki/Gurney_flap

 

a twisted leading edge would help too

Edited by Dalslandia
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I am only really guessing since to make any really valid assessment you'd need to try to steer the offending boat but as a suggestion is the rudder likely to be slightly off-line to the prop? Is the skeg out of alignment? I don't really accept the 'prop wash' theory since the faster the boat goes the less effect you get from prop wash so it is only really noticeable when the boat is moving really slowly. My own boat has a tiller/rudder that naturally goes to the dead centre setting even if I were to let it go altogether whilst on the cut, it seems from what the OP was saying if he released the tiller the boat would immediately steer with a bias, something is clearly wrong. Since we all have prop-wash to a greater or lesser degree my thought is that it must be something else, and a bent skeg seems to me a possibility. This would mean that the prop thrust would always be adversely deflected by the rudder, requiring the helm to continuously try to correct it, hence the continuous (and tiring) steering to one side.

I'm liking this theory. A skeg bent to port would explain why the rudder appeared to be off to port when looking down the swan neck and, if my theory is correct, would present more of the starboard surface of the rudder to the prop thrust thus causing the deflected rudder to push the boat to starboard. That would be in line with the symptoms that we had with regards to the increased effect with increased rpm and the apparently normal tiller operation when drifting forward out of gear. Shame I can't see it out of the water to confirm, maybe the hire company will get back to me when they next have it out of the water!

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That was my question, I didn't wrote, if with some good speed, going into neutral gear, is the tiller still heavy? if so as you say there is something wrong and not just from prop wash

I never tried it out of gear with any real speed, only at low speed so the effects would have been much less noticeable either way and anyhow, I was usually too busy concentrating on trying to position the boat at those moments so I didn't notice. If I hadn't been on honeymoon then I probably would have come onto the forum whilst aboard but I don't think that would have gone down so well with her indoors . Can't wait to get our own boat so that we can join in here a bit more.

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To a greater or lesser extent, most boats 'drift' off in one direction or another when left to their own devices.

 

Assuming nothing's bent and there is deep water under and at each side of the boat, I would say the biggest influncing factor is the alingment of the shaft, shaft tube in comparision to the fore to aft alignment of the boat.

 

The tube only has to be slightly out and you have a slight thrust pushing the boat constantly in one or the other direction. The bigger the error, the more corrective force is need to compensate with the rudder. Very diffucult to cure once the boat has been commisioned

Edited by Proper Job
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