Numbers for new Cat

General Sailing Forum

Last Post by Tad Pecorak 24 years ago

5 Posts

4 Users

0 Reactions

1,465 Views

RSS

Matt M

(@matt-m)

Posts: 686

Member

Topic starter

[#10203]

I know that this has been posted in the past, however, I am not finding it with the search engine. I am looking for the link to the site to calculate the Texel/provisional portsmouth number for catamarans.

Specifiaclly I am looking to find the provisional number for the new 3D-20 that Vectorworks Marine is building. The first boat is due to be launched this summer, depending on the delivery of the rig that randy Smyth is designing.

Any help finding this link would be appreciated,

Thanks

Matt

Posted : July 2, 2002 11:44 am

Sailwave

(@sailwave)

Posts: 255

Member

Wouter has a Texel calculator on-line somewhere and ISAF have one for (ISAF SCHRS) at www.schrs.com.

Posted : July 3, 2002 6:34 am

wouter

(@wouter)

Posts: 9363

Three Star Admiral Registered

The calculators for both the Texel system (I made) and the ISAF small cat system are intended for small beach catamarans and I don't know how competable they are for the much bigger cat you talk about.

But the Calculators can be found here :

http://www.geocities.com/f16hpclass/F16HP_ratings.html

http://www.geocities.com/kustzeilen/ Under de header "home links"

Hope this helps;

Wouter

Posted : July 3, 2002 7:48 am

Matt M

(@matt-m)

Posts: 686

Member

Topic starter

Wouter and Colin

Thanks, but this brings up a few questions.

This boat is 20ft (6m) so it should fit within the guidlines of this rating system. I notice that there are no factors in the calculations for items such as beam, hull fineness ratio etc. I would assume that that this is because the designers would all create hull shapes within fairly close dimensional ratios, and that sail area would be increased proportionaly to the beam width on wider boats, and the sail area is a used factor. Do you guys have any knowlege on the background behind the formula.

Also, I remeber seeing Wouter tossing around some numbers to approximate a conversion between systems. Unfortunately the portsmouth system is used the most frequently around me. Any input would be appreciated.

We've finally got a Holiday weekend here in the States, and I'm very much looking forward to 4 days of some major big wind sailing in the sandhills.

Have a great one,

Matt

Posted : July 3, 2002 9:25 am