VoyForums
[ Show ]
Support VoyForums
[ Shrink ]
VoyForums Announcement: Programming and providing support for this service has been a labor of love since 1997. We are one of the few services online who values our users' privacy, and have never sold your information. We have even fought hard to defend your privacy in legal cases; however, we've done it with almost no financial support -- paying out of pocket to continue providing the service. Due to the issues imposed on us by advertisers, we also stopped hosting most ads on the forums many years ago. We hope you appreciate our efforts.

Show your support by donating any amount. (Note: We are still technically a for-profit company, so your contribution is not tax-deductible.) PayPal Acct: Feedback:

Donate to VoyForums (PayPal):

Fri, March 29 2024, 05:35Login ] [ Contact Forum Admin ] [ Main index ] [ Post a new message ] [ Search | Check update time | Archives: 123456[7]89 ]


[ Next Thread | Previous Thread | Next Message | Previous Message ]

Date Posted: - Friday - 09/28/07 - 8:52pm
Author: Randall, M31
Subject: The keel's to blame :)
In reply to: Jake 's message, "Rudder?" on - Friday - 09/28/07 - 2:24pm

Personally, I think being slow to come about is the nature of things for a full keel boat with lots of windage up top—i.e. two masts and all the extra rigging. Murre is never quick in stays (quickness is not really in the cards for Murre), but typically we only miss stays when tacking into a thick chop. Then, if the wind is light, the chop can knock too much way off before we’ve swung around, or if the wind is really honking, the chop and the windage can stop us cold. Even then, we can usually time the tack with the chop to get the best advantage. And we always use the jib to pull her head around.

It’s hard to imagine a larger rudder on Murre. The thing is already as big as a barn door. And I’m not sure bigger, beyond a certain point, is better. The issue is not lack of turning force, but rather the drag that the hull’s wetted surface creates, and especially when it’s turning. A full keel going 5 knots can only be made to go about so fast.

Might be a good question for Terry of Valhalla who can be contacted via the Fuji yacht bulletin board. I was looking through his 2006 refit photos the other day and noticed he has recently enlarged his fiberglass rudder on his Fuji 32. But it started out much smaller than the Mariner rudder and is now the same shape and size as mine.

Valhalla refit photos here: http://www.yachtvalhalla.net/projects/refit2006/refit2006.htm

RR

[ Next Thread | Previous Thread | Next Message | Previous Message ]


Replies:

[> [> you are correct, sir! -- ian mcgehee, - Tuesday - 01/15/08 - 5:38am

Backwinding the jib- learn it, live it, love it!

Besides the drag issue you mention, another reason that rudder modifications shouldn't be made without *very* careful consideration is that even small changes in rudder area can cause the hull's center of lateral resistance to move forward or aft...increasing the rudder area enough will do the latter, which will gradually introduce lee helm (or maybe not so gradually). Not only will this defeat the purpose of trying to make the boat easier to tack, lee helm can be dangerous.

Messing with your rudder design is kind of like messing with the fork angle on a motorcycle...it can be done and serve a purpose, but it isn't something to do unless you *really* know what you are doing, because even very small adjustments can have a major impact on your steering, and not necessarily the one you were going for.


[ Edit | View ]





[ Contact Forum Admin ]


Forum timezone: GMT-5
VF Version: 3.00b, ConfDB:
Before posting please read our privacy policy.
VoyForums(tm) is a Free Service from Voyager Info-Systems.
Copyright © 1998-2019 Voyager Info-Systems. All Rights Reserved.