Depends on whether it it a right or left hand screw of course.

Cheers MC

Simple Simon wrote:

Walking and rudder power are intmately related.

Walking is more a natural function of how a propeller works
that has to be counteracted by a rudder to keep it from
having its way.

For example, you are aboard a right-handed single screw
vessel with headway on. The engine is put full astern and
the rudder hard left. The bow will first swing to the left and
the swing to the right as the vessel loses way.

The swing of the bow to the left is a function of rudder control
while the swing to the right as the vessel loses way is caused
by the prop walk overcoming the effects of the rudder because
of the decreased speed and decreased rudder control.

I hope this helps.

S.Simon.

"otnmbrd" wrote in message k.net...


DSK wrote:


In harbors the world over. I mean everywhere, We all know where they put
Multi-Hulls. on the very end slips of finger piers or bouyed mooring.

The Captains Nemesis wrote:
Interesting.
Here the cats tend to be deep into the marinas (other than casuals)
because they have the ability to turn in there own length under power


No doubt that cats under power with wide spaced twin engines are very
maneuverable under power.



Let's face facts; a Multi trying to manouver ( Over even making a simple
turn in tight quarters) is not a pretty thing. Even under power.

Skilled hands make light work under power. Juggling thrust can walk a
cat sideways and maneuver in ways that monos can only dream.


I'd like to see that. Theory suggests that with small props & rudders, prop
walk and kick aren't going to move it sideways much. In practice??

Interesting .... I'd have thought the opposite.
Since "walking" is highly dependent on rudder power and most sailboats
tend to have better than average power in this area and a "cat" doesn't
tend to have a great deal of wetted area and or windage (exceptions
noted), I'd have guess them to be good candidates for "walking".

otn

Pages written by lubbers! Fancy not saying what hand the screws are!

Cheers MC

Jeff Morris wrote:

2GM20FC with SD20 Saildrive, bottom of page:
http://www.yanmar.com.au/marine/Sail...sailseries.htm

Also, the props are shown on this page - search for 872880
http://www.penta.volvo.se/files/kapitel45-gb.pdf

"Simple Simon" wrote in message
...

Hey silly, Yanmars turn clockwise looking at them from the stern.

Unless you have a weird, v-drive tranny or something your props
turn clockwise.

S.Simon

"Jeff Morris" jeffmo@NoSpam-sv-lokiDOTcom wrote in message

...

Both turn the same way, Counterclockwise, when viewed from the stern. I think. I
actually had a prop in my hand this afternoon to bring home, and decided that was

silly!

But I do know for sure they both go the same way!

"otnmbrd" wrote in message
thlink.net...

G May be wrong answer .... when looking from astern, both props turn
clockwise, when engines ahead? or does stbd turn one way and port, the
other? (may be part of the reason for no walk).

otn

Jeff Morris wrote:

Yes.

There're not counter-rotating.

As to what happens when I try to "walk" - I can't quite remember exactly - she

just

jiggles forward or back but never really gets and loser to the dock! Of course, I

wish we

had this discussion yesterday, I could have tried it out this morning! But as

they

say

here in Boston, "Wait till next season!"

"otnmbrd" wrote in message
rthlink.net...


Dang it! That's twice I forgot to ask .....inboard or outboard turning
props?

otnmbrd wrote:


Walk set-up is correct (props control bow, rudders control stern). Don't
think your keel (from what I saw in the picture) is the problem.
Seemingly (but not) unimportant question .... which end lags behind ....
bow or stern? (in your example, hard right rudder, engines clutched,
only,[no throttle] for left twist) BTW, I'm hoping you say bow, lags
behind G.

otn

Jeff Morris wrote:



Oy! You had to ask! It isn't easy to remember with the controls in
front of me, but I
guess:

To walk to Port, Rudders to Starboard, Port Engine in Reverse,
Starboard Engine Forward.

The works with many twin screw boats, but I think mine has a keel that
too long - I wonder
if its too efficient at low speed? Also, although the rudders are
large, they are hung on
skegs and set back a bit from the screws, which are folding. I think
all these things add
up to minimal "walking."

-jeff



"otnmbrd" wrote in message
.earthlink.net...



G It varies a lot with all multi screw (except tractor tugs). From the
look at the picture, I would think she'd "walk" fairly well ( I'm
talking about sideways motion, not prop walk).
Just out of curiosity, when you set up to "walk" to stbd, how do you set
your engines and rudders? .... and which part has the problem keeping
up, bow or stern?

otn

Jeff Morris wrote:



And the answer is:

It varies a lot with the cat. Some have long keels, others have
daggerboards. Some


have



steerable drives, some have a single outboard, some have a widely
spaced diesels.


Some



have little windage, others a lot.

My boat has long keels, low windage on the bow (more aft), and
widely space diesels.


She



can pivot in place very nicely but has little prop walk. People
have told me they


could



make it go sideways, but when I've challenged them to try, they've
always failed. I


often



have to dock on a face, which is actually often tough - I usually
rely on getting


close



enough to snag a cleat, then springing in the rest of the way. If I
have a few hands
around to help I can usually get the boat anywhere I want. The
hands don't have to do
much of anything, but I find it difficult to singlehand because the
visibility around


the



edges is limited.

This morning I had a special challenge - I had to back into a
TravelLift the is about


6



inches wider than my beam. The wind started light, but picked up
to about 15 knots


cross



as I was coming in. The real problem was that one prop had trouble
staying open in
foreword - I had to do most of the work with just one engine. This
made it difficult


to



stay lined up. I felt that I totally turkeyed it, but I was
complimented by the Lift-
Meister and dockhand, and no damage was done. I found that the
gearing that forces to


two



blades to open together had totally sheared off.

Here's a pic taken slightly later:
http://www.sv-loki.com/Img_1616a.jpg

Depends on whether it it a right or left hand screw of cours

Neal rarely gets either.

RB

I'm just the opposite - I can't bear the thought of
having it done without being there.

I feel the same way but I cringe through the whole process....ever seen =
one dropped? It ain't pretty....
--=20
katysails
s/v Chanteuse
Kirie Elite 32
http://katysails.tripod.com

"Women and cats will do as they please, and men and dogs should relax
and get used to the idea." - Robert A. Heinlein

Subject: Inherently beautiful.
From: =?ISO-8859-1?Q?The=5Fnavigator=A9?=
Date: 10/21/2003 13:07 Pacific Standard Time
Message-id:

Depends on whether it it a right or left hand screw of course.

Cheers MC

Simple Simon wrote:

Walking and rudder power are intmately related.


The discussion in question, was way over Neal's head and/or experience.

Shen

Why do you say that? Why did you decline to respond
to my post about the affects of rudder vs. prop walk
in the situation I described? Was it because you failed
to understand what was said?

S.Simon


"Shen44" wrote in message ...

The discussion in question, was way over Neal's head and/or experience.

Shen

Subject: Inherently beautiful.
From: "Simple Simon"
Date: 10/22/2003 05:36 Pacific Standard Time
Message-id:

Why do you say that? Why did you decline to respond
to my post about the affects of rudder vs. prop walk
in the situation I described? Was it because you failed
to understand what was said?

S.Simon


This post, and the one, from you, which brought about my response, highlights
the reason for my response.
They were not talking about single screw "prop walk". They were talking about
making, or the possibilities of making, a twin screw boat "walk" sideways.
Your post was a dissertation on a basic "motorboat" maneuver, with a fixed
pitch, right hand propellor. (possible exceptions noted)
The fact you weren't aware of this and made your post, showed that the topic
was "over your head and/or beyond your experience".

Shen

Duh! Two fixed props spinning in the same direction
as on Jeff's catamaran will act the same was as one
fixed prop on a monohull.

You sure you're a licensed captain. You just aren't
too bright.

S.Simon


"Shen44" wrote in message ...
Subject: Inherently beautiful.
From: "Simple Simon"
Date: 10/22/2003 05:36 Pacific Standard Time
Message-id:

Why do you say that? Why did you decline to respond
to my post about the affects of rudder vs. prop walk
in the situation I described? Was it because you failed
to understand what was said?

S.Simon


This post, and the one, from you, which brought about my response, highlights
the reason for my response.
They were not talking about single screw "prop walk". They were talking about
making, or the possibilities of making, a twin screw boat "walk" sideways.
Your post was a dissertation on a basic "motorboat" maneuver, with a fixed
pitch, right hand propellor. (possible exceptions noted)
The fact you weren't aware of this and made your post, showed that the topic
was "over your head and/or beyond your experience".

Shen

Subject: Inherently beautiful.
From: "Simple Simon"
Date: 10/22/2003 10:07 Pacific Standard Time
Message-id:

Duh! Two fixed props spinning in the same direction
as on Jeff's catamaran will act the same was as one
fixed prop on a monohull.

You sure you're a licensed captain. You just aren't
too bright.

S.Simon


ROFLMAO DUH!!! You STILL don't understand what was being discussed ..... as
stated twice before WAY over your head and experience!!


Shen

From: (Shen44)
Date: 10/22/2003 10:39 Pacific Standard Time
Message-id:

Subject: Inherently beautiful.
From: "Simple Simon"
Date: 10/22/2003 10:07 Pacific Standard Time
Message-id:

Duh! Two fixed props spinning in the same direction
as on Jeff's catamaran will act the same was as one
fixed prop on a monohull.

You sure you're a licensed captain. You just aren't
too bright.

S.Simon


ROFLMAO DUH!!! You STILL don't understand what was being discussed ..... as
stated twice before WAY over your head and experience!!


Shen


Snif? Snif? Smell the beginnings of an electrical overload, as Neal frantically
searches the web, looking for information on twin screw "walking"

Shen