12 Metre design

[phum]

Hello all,
I am interested in the bustle,both for and aft, used on the later 12 metres.
Anybody know where info could be found, photos or links would be appreciated.
Thanks, Peter.

[booster]

Hi!
Sparkman&Stephen's Couragous had bustle both for and aft. The aft bustle was tested on earlier boats as well. The for bustle was increased to near its limits at the design Tom Blackaller sailed (Independence?): "The boat pushed water in front of it". During the tests before Fremantle Dennis Conner even tested a bulb. However, it only worked properly in flat water. The Start&Stripes that took back the Cup to the US had a compromise bustle in the bow. It slightly resembled a bulb and was nicely integrated with the gondola bow. Try to Google for sites on the subject.
Regards,
Booster

[phum]

I have used Google but not much luck.
I want to know pros and cons, what works what doesn't and why.
Peter

[ABoatGuy]

Keep in mind many of the bustles, both in 12m and IOR design were rule beaters and had little to do with pure boat speed.

[phum]

I am aware of this, thanks

[booster]

Phum!
I Googled as well, with little results. A photo of a much debated bustle you can find under "The Britton Chance portfolio" on this site. The Mariner bustle still confuses designers.
Regards,
Booster

[booster]

Phum!

http://www.sparkmanstephens.com/yach...er_designs.php

"During this period, Olin experimented with how the wetted surface of a hull could be reduced (for less drag and greater speed) without endangering the seaworthy qualities of the boat. As a result of his model testing, he concluded that "wetted surface aft was not as harmful, perhaps, as it was forward because the water by then was already going with the boat," leading to the creation of a "bustle" in the waterline of Constellation."

Regards,
Booster

[phum]

Any idea what other metre classes employed bustles?
I did find one small peice by Stephen Jones that said a stern bustle was a good way of distributing displacement in a heavier displacement hull or words to that effect.
Peter

[Paul Kotzebue]

Originally Posted by phum

Any idea what other metre classes employed bustles?

The six meters are more or less scaled down 12 meters and they have similar bustles. The bustle is a means of reducing the measured length by abruptly changing the hull shape just ahead of the aft girth measurement station. A bustle makes sense any time sailing length is measured between girth stations, such as the IOR and meter class rules. Those are the only racing boats that have bustles that I'm aware of.

[PAR]

At the end of the CCA era they employed bustles too.

[Paul Kotzebue]

Originally Posted by PAR

At the end of the CCA era they employed bustles too.

I know bustles started showing up on IOR boats shortly after the rule was introduced around 1970. I've also heard of pre-IOR boats being modified to incorporate a bustle to be more competitive under IOR. I'm interested to know what CCA boats were built with bustles prior to the IOR. It is conceivable the designers were anticipating the boats would be raced under the new IOR rule.

[PAR]

I had a 35' Lion class sloop, converted as a yawl under CCA, but it incorporated a bustle. I could only speculate the designer's logic, but it was fairly clear a tactic to beat a rule.

[dskira]

Originally Posted by phum

Hello all,
I am interested in the bustle,both for and aft, used on the later 12 metres.
Anybody know where info could be found, photos or links would be appreciated.
Thanks, Peter.

My question to your post will be : why?

Cheers
Daniel

[dskira]

Originally Posted by phum

I have used Google but not much luck.
I want to know pros and cons, what works what doesn't and why.
Peter

To complete my previus post why you want to know the pro and con?
What will be the use for when you have the information, meaning half will said it works, half will said it don't.
In which parameter you will want to incorporate an appendice?
Just curius.
Cheers
Daniel

[Paul Kotzebue]

Originally Posted by PAR

I had a 35' Lion class sloop, converted as a yawl under CCA, but it incorporated a bustle.

Is that an Arthur Robb designed Cheoy Lee Lion?