Chine Walking

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Lawsy

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Whilst out yesterday with Mrs Lawsy & Kawasaki (see other threads), the term chine walking came up in relation to how Blue Moon handles under certain conditions. I had never really come across the term before & we had a bit of chat about what causes the effect. However due to other issues (not least how to get back to my pontoon with a bl**dy dredging pipe in the way /forums/images/graemlins/smile.gif) we never discussed the matter fully. I've now been on line this morning but cannot find much about the cause; effect; solution regarding chine walking. Can anybody help please?
 
Never had it, AFAIK. But I think it's when the side (corner) of the boat, trys to act as keel. Not explained very well. Dont think you can do anything about it, except maybe change direction till it stops, then try again.
 
The conditions were:- a bit of speed; a bit of chop; a bored (therefore moving around) dog; Mrs Lawsy trying to keep bored dog entertained. Whatever the solution, I don't think that any boating manuals will specifically say 'Stop the dog & Mrs Lawsy moving around' /forums/images/graemlins/smile.gif.
 
Chine walking is where the whole boat "flops" to one side, and is riding on the flat part of the V and the edge (chine). You try and correct with tabs/engine, and it "flops" all the way to the other.

It's very uncomfortable: you'd have an unhappy crew if it was happening.

It's not the same thing as the boat just heeling over a bit cos swmbo decides to change position.

Possible solutions:
- Put swmbo and dog on a diet
- Fit heavier engines or load up with 250 tins of Fray Bentos stowed along the keel
- Slow down
- Fit a new hull

dv.
 
I had the same thing the other day

Found that one tab was not retracting all the way, unless I held the switch for ages and then it went up.

This meant that the other tab was down a little. So, the blunt bit was not sitting in the water enough.
 
"15. Chine walking and loss of steering control. At high speed, boat lays over on its side. Trim tab inputs result in extreme and unwieldy responses. The causes of this are complex, but well known. The main reason this occurs is that the designer didn't know what he was doing, and the builder didn't bother to test the performance, or bother to correct the problem. He gets away with this by ascribing the problem to "operator error." Large numbers of boats are affected with this problem. "

From David Pascos website www.yachtsurvey.com
 
Good answer S28 to Lawsey's good question.
I think it was (as Lawsey is in His first full season) L Capitano's longest spell at the Helm yesterday.

Unberthing, a decent hour or two 'On Passage' and re berthing from a different appraoch than usual. Well done that Man.!

Just along for the ride, I kept more quiet than usual!
But threw 'Chine Walking' in for good measure and to provoke thought, seems to have worked!

L Capitano's Doral doesn't actually chine walk severly but at one point due to the wave pattern and wind condition, She did lean to Port for a Mo.

Accentuated, as mentioned by the distribution of canine and crew etc.

'Hard Chine Vessels' another description used to describe certain boats.
The Chine as S28 points out is the 'ridge' along the hull that can 'dig in' to the water and the boat can feel like its on rails.
The rails seem to be going where the Helm does not on some boats!

It is a combination of design, trim and weight distribution.
Does not happen with displacement vessels and is rare with semi displacement.

It can never happen on hlb's boat due to the weight of tabbaco on board and Henry is only a little dog, however I wouldn't want to nick His food bowl --- ever!!

Next question L Capitano.
What's the difference between 'Cavitation' and 'Aeration'? /forums/images/graemlins/grin.gif /forums/images/graemlins/smirk.gif /forums/images/graemlins/tongue.gif
 
What's the prize?

Aeration is if an outboard or outdrive is running too high. Or you remove the plate above the prop. Air is sucked around the prop & your prop ends up running in bubbles. Lots of bubbles and noise. Not much forward motion.

Caviation is where the water separates from the surface of the prop and causes tiny vacuum bubbles which collapse with a hell of bang on the prop surface and damage it. Either the prop too small, the wrong shape, or you're going too fast.
 
My little Bayliner 2556 did it. Generally only when I'd overloaded the little flybridge, but when you are up high on a little boat it is alarming, It felt like she was going to capsize. I found I could flick the helm to bring her upright, and a bit of tab boat sides would help stop in happening.
 
[ QUOTE ]

What's the prize?



[/ QUOTE ]

I award You with the Prize of giving Me a go in your boat next time I,m down your way.

We can explore aeration and have a dabble at some chine walking /forums/images/graemlins/smirk.gif /forums/images/graemlins/laugh.gif
 
[ QUOTE ]
The most talked about boat with the 'Chine Walking' problem was the Sealine S41 pre 2002. I believe the cure was to either hang a dingy off the back or install auto trim tabs. I thinkthe Yanmar/Mercruiser installations caused the most problems

[/ QUOTE ]

That's my boat folks... I've never had a problem with chine walking and have used it in all sorts of weather. Can't see why the blame may lie partly with an engine/drive package either and AFAIK the Yanmars are lighter than the nomal Volvo package so I fail to see why a lighter rig might be more prone to walk??
I'll sit back now and stand to be corrected!!!
 
Lighter rig means the hull is riding just that bit higher in the water at speed. So less of the "V" remains in the water to provide stability.
 
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