I was in error. My mail should have read uninformed.
Steve, you're excepted, this time.

Stephen Baker wrote:

Jim Conlin says:

This thread has reached a new high in the concentration of uniformed twaddle.

I'm going to hope you're wearing fireproof undies, Jim. ;-)

Steve "wonders if he's included in the above - planning revenge if so..."

Jim Conlin says:

Steve, you're excepted, this time.

Good save. ;-)

Wayne.B ) writes:
On Fri, 08 Oct 2004 07:25:53 GMT, Morgan Ohlson
wrote:

Boats with a Cat rig have a tendencie towards max beam and max draft closer
to the bow.

=============================

Since the center of effort (CE) is further forward on a cat rig, the
center of lateral resistance (CLR) needs to be further forward also in
order to keep the boat balanced.


I think if you'll look at a New England style cat boat you'll see than it
has a very large sail with a long boom so the CE is further aft. The keel
is about where it would be on any other hull. the mast on a laser is
stepped in the usual position. in fact the lack of a jib moves the CE
of the sail plan further aft so the mast can stepped further forward.
on small boats just put the daggerboard under the CE no matter where the
mast is stepped. On a recent design I moved the cat rig mast forward so the
centreboard would not be in the way in the cockpit. With the optional
ketch rig the centreboard was not in the way with the mast in the more
normal position.
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On 08 Oct 2004 10:06:25 GMT, Stephen Baker wrote:

Morgab Ohlson says (and I may misquote due to an eccentric quoting style used
previously):

Boats with a Cat rig have a tendencie towards max beam and max draft closer
to the bow.

...that must be because of the mast weight, isn't it?

More probably because that was the "right" shape for a boat during the years
(hundreds of them) the cat rig developed - as for the draft, that is usually
deeper at the stern, unless you are talking purely about the canoe body, in
which case it is all part of the "wider section, deeper section" thing.

A difference in sailpower between a front or rear mast position is the roll
forces applied.

Do tell. Roll forces should be identical, although the yawing forces as a
result of position will change. So will the overall balance of the boat, big
time.
Look in Chappelle sometime, and compare the underwater parts of catboats to
schooners. See what I mean?

Steve

Sorry, I don't undertand the "yawing force".

I expressed myself stupid. Naturally the roll force is the same, but I ment
that the hull reaction to it must be different since the hull beam profile
(angle to centre line) is different towards the bow.


Morgan O.

On 08 Oct 2004 10:06:25 GMT, Stephen Baker wrote:

Morgab Ohlson says (and I may misquote due to an eccentric quoting style used
previously):

Boats with a Cat rig have a tendencie towards max beam and max draft closer
to the bow.

...that must be because of the mast weight, isn't it?

More probably because that was the "right" shape for a boat during the years
(hundreds of them) the cat rig developed - as for the draft, that is usually
deeper at the stern, unless you are talking purely about the canoe body, in
which case it is all part of the "wider section, deeper section" thing.

A difference in sailpower between a front or rear mast position is the roll
forces applied.

Do tell. Roll forces should be identical, although the yawing forces as a
result of position will change. So will the overall balance of the boat, big
time.
Look in Chappelle sometime, and compare the underwater parts of catboats to
schooners. See what I mean?

Steve

Steve
Stephen C. Baker - Yacht Designer
http://members.aol.com/SailDesign/pr...cbweb/home.htm

I read somewhere that masts, before Al, graphite and "glued stringers masts"
was much heavier which forced the CB (buoyance) to follow the mast....


Morgan

Morgan Ohlson ) writes:

Sorry, I don't undertand the "yawing force".

pitch: vertical rotation parallel to centreline
roll (or heel): vertical rotation perpendicular to centreline
yaw: horizontal rototation perpendicular to centreline

"yaw: a vessel's sudden verring from the course"

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"yaw: a vessel's sudden verring from the course"

"yaw: a vessel's sudden VEERING from the course"

sorry about that
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