Port of MDI
- Technical
- Abbreviations, Definitions, Formulas and Terms
MDI's "First Order" evaluation of Multihulls an explanation from the basics to performance and stability. - Hull Cross Sections for Multihulls
Most multihull design books include a section about the pros and cons of various hull cross sections. They dont always agree with each other, and when that happens, it begs the question of why not. The intent of this piece is to shed a little light on that question.
- Bridgedeck Clearance for Catamarans Revised 1-'10
The following standards for Bridgedeck Clearance (BdCl) have been discovered through the literature and direct contacts with the sources:
- Six Kinds of Cats and Two Kinds of Tris
By Calvin H. Markwood
"Six Kinds of Cats and Two Kinds of Tris" documents the use of the same analytical methodology to compare the designs of prominent catamaran and trimaran designers.
The catamaran designers are Brett Crowther, Kurt Hughes, Derek Kelsall, the team of Morrelli and Melvin, John Shuttleworth, and Chris White. The trimaran designers are Ian Farrier and Dick Newick.
- Analysis and Comparison of Cruising Multihulls 2009
Article Presentation
This is the full and complete presentation of article "Analysis and Comparison of Cruising Multihulls 2009". This article describes "First Order" multihull design analysis. It is the description of the analysis and comparison methods of multihulls on this website.
- 'Multihull Design Considerations for Seaworthiness'
Multihull Dynamics' incorporates evaluation methods developed and elaborated by John Shuttlesworth. - Stability Index - Calvin Markwood (SI-CM)
Multihull Dynamics uses two formulas to evaluate multihull stability. One is well known and has been a bit modified by one or two designers. We use John Shuttleworth's version of that formula on our site, Stability Speed (SSpd). For a detailed discussion of that formula see Stability Speed (SSpd) in the Technical papers.
Cal Markwood has developed another formula that we also use, Stability Index (SI-CM). It is identified onour evaluations as SI-CM. Here is how Mr. Markwood derived the formula.
- Bow Bulbs
Most ocean-going cargo vessels are built with a large bulb protruding forward from the hull, below the waterline. The purpose of these bulbs is to reduce or eliminate the bow wave and thereby increase speed or reduce power required. The applicability of these bow bulbs to multihulls is an intriguing topic.
- Classifying Multihulls
When viewing, shopping, admiring multihull sailboats, it is easy to become enthralled with the prospect of high performance - meaning speed. Sailing past another boat is probably one of the primitive urges of man.
- UNCONVENTIONAL CONCEPTS
Anti Vortex Panels - Analysis of Multihull Sailboats
Many people in the process of buying cruising multihulls are frustrated when attempting to sort fact from fiction. Here is the background about MDI's "First Order" Evaluations
- Technical Submissions
We are interested in presenting your work and thoughts on multihull sailboats. - Database Maintenance
To develop the database for the Multihull Dynamics Inc. website, boat specifications were collected over more than a decade from boating books, magazines, websites and communications directly with designers, builders and brokers of Multihulls.
- Stability Speed - SSpd
John Shuttleworth offers a formula for the wind speed in miles per hour at which hull lifting will occur in his design booklet "Multihull Designs".
- Texel Rating: Multihull Handicap System
Texel Rating is a system which allows different multihulls to race against each other. This system is originally developed by Nico Boon for the biggest cat-race in the world, the Ronde om Texel (the Texel Round) in The Netherlands. Later this system was extended to sea-going catamarans and trimarans.
- Bow and Stern Overhang Effects
Multihull design pioneer Hugo Myers evaluated the effects of bow and stern overhang on boat performance and hence on rating systems. This paper is about how his thoughts relate to certain boats in our Database.
