• * Foam Core Materials in the Marine Industry  
  For over 60 years foam cores have been utilized in marine applications to lighten, stiffen, and strengthen everything form hull bottoms to fly bridges. But what exactly is foam core? What type do I use, and where can I use it? Should I use it instead of balsa or plywood? This article will attempt to inform boat builders about the properties and correct manufacturing procedures involved in constructing foam core sandwich laminates. (Added: 6-Apr-2002 Hits: 8189)  Rate | Cached | Visit * Foam Core Materials in the Marine Industry

• * Free Forming in Fiberglass  
  Fiberglass is a very good material for boats. The main problem with building a fiberglass boat is getting a smooth surface. With conventional molds derived from male plugs, the smooth surface is achieved by hundreds of hours of fairing, filling and sanding on the plug. For a one-off fiberglass hull, this process is even harder because the relatively soft, easily faired materials used for plug construction cannot be used for an actual hull. One very interesting technique to get around this problem is fiberglass freeforming or direct female molding. Free-formed fiberglass gets most of the hull mold surface smooth without sanding, but at a cost -- you must use developable shapes for the easily faired surfaces. Here is how it works. (Added: 11-Mar-2005 Hits: 19362)  Rate | Cached | Visit * Free Forming in Fiberglass

• * History of Sailing Yacht Masts, Rigging and Sails 1900-Present Day  
  The design, construction and materials of masts, rigging and sails have changed greatly over the course of the 20th century. From solid wooden masts built from a single tree to carbon fibre sections aerodynamically tested, super light and super strong. Sails have changed from natural materials such as cotton, which had a tendency to rot and stretch when wet, to new materials such as North sails 3DL sails using Vectran, carbon fibre, Kevlar and exotic films and glues. (Added: 10-Mar-2002 Hits: 6000)  Rate | Cached | Visit * History of Sailing Yacht Masts, Rigging and Sails 1900-Present Day

• * Revisiting a Mast-Aft Sailing Rig  
  Development of a sailing rig which discards the "inefficient mainsail, and replaces it with two clean leading-edge headsails, acting in a parallel, harmonious fashion" with a mizzen sail creatively added and the mast stepped aft in the cockpit area and canted forward 10 degrees. Brian Eiland. (Added: 10-Jan-2002 Hits: 5726)  Rate | Cached | Visit * Revisiting a Mast-Aft Sailing Rig

• * What makes the tunnel hull work?  
  A three-part article written by Jim Russell of AeroMarine Research which summarizes the main hydrodynamic and aerodynamic forces which must be carefully considered and skillfully balanced in the design of a tunnel hull powerboat. While the tunnel hull derives much of its high performance from air lift, it depends at the same time on its planing interaction with the water to maintain a stable and controlled flight. This interdependence of water and air force dynamics is the key to Tunnel design. (Added: 11-Feb-2002 Hits: 7900)  Rate | Cached | Visit * What makes the tunnel hull work?

• * Working With Developable Surfaces  
  Developable surfaces are important to the home boatbuilder working with sheet materials like plywood, steel or aluminum. Developable surfaces can be formed from flat sheets without stretching, so the forces required to form sheet materials into developable surfaces are much less. In some cases, particularly with plywood, the forces required to form non-developable surfaces could be so large that the material is damaged internally. Another advantage of developable surfaces is that the development of such a surface is exact. When other types of surfaces are expanded the shape of the expansion depends on the distortion field applied to form it. If you are designing or lofting plywood or metal hulls you should understand developable surfaces and the methods for working with them. (Added: 21-Mar-2005 Hits: 15249)  Rate | Cached | Visit * Working With Developable Surfaces

• 5-Axis Milling for Plugs, Molds, and Tooling  
  Now that designers are adopting computer methods for modeling and fairing 3-dimensional hull surfaces, it seems reasonable to use the computer surface model to mill full-size male or female plugs, or even produce complete tooling by CNC machine. The promise is better accuracy, less cost, and faster turn-around time. This article discusses some of the things you need to know about the process before you jump in with both feet. Although the focus is on using outside services, the information will still be useful for those considering whether to buy their own equipment. Stephen M. Hollister. (Added: 10-Jan-2002 Hits: 6576)  Rate | Cached | Visit 5-Axis Milling for Plugs, Molds, and Tooling

• A Design Revolution  
  If you have not bought a new powerboat in the last few years you may have missed a quiet revolution in design that has taken place. Subtle changes in hull design have produced performance benefits which were not possible previously. The newer boats plane a little more efficiently but the biggest change is in the cornering. Flat turns are very prominent in the new generation of vessels afloat. Patrick J. Bray. (Added: 10-Jan-2002 Hits: 10202)  Rate | Cached | Visit A Design Revolution

• A Performance Prediction Model for Rowing Races  
  A mathematical model of the forces acting on rowing boats has been developed. The model takes into account the motion of the rowers' bodies during the stroke, as well as variations in stroke rate at the beginning of a race. Hydrodynamic resistance is estimated using the 1957 ITTC line for the skin friction, an empirical formula for the form drag, and Michell's integral for the wave resistance. Leo Lazauskas. (Added: 10-Jan-2002 Hits: 5253)  Rate | Cached | Visit A Performance Prediction Model for Rowing Races

• Aluminum for Boats  
  This article first appeared in the September 1997 issue of Cruising World magazine. It includes several good images showing different hull forms suited to metal construction, the relative advantages of each, and what factors one should have in mind when considering the use of aluminum as a hull construction material. Michael Kasten. (Added: 10-Jan-2002 Hits: 8254)  Rate | Cached | Visit Aluminum for Boats

• Aluminum vs. Steel  
  The choice of hull materials is the most fundamental of choices when considering a new vessel design, or even when considering the purchase of an existing boat. If you intend to make use of metal as a hull material this article will be of some value in that choice. It will shed some light on the various ways to compare steel versus aluminum for a boat's structure. Michael Kasten. (Added: 10-Jan-2002 Hits: 7439)  Rate | Cached | Visit Aluminum vs. Steel

• Archive: Anchor Catenary Details  
  A model of the rode shapes (catenary) associated with various anchor systems including kellets. (Added: 18-Mar-2002 Hits: 3705)  Rate | Cached | Archive

• Anthony Steward - Around Alone in an Open Boat  
  Ant Steward is the only person to have sailed around the world in an open boat, a custom version of the TLC 19 designed by Dudley Dix. This is a review of his voyage and his motivations. Dudley Dix. (Added: 10-Jan-2002 Hits: 5871)  Rate | Cached | Visit Anthony Steward - Around Alone in an Open Boat

• Automatic Hull Variation and Optimization  
  Design optimization is complicated by the infinite variability of the hull shape and the close interrelationship among all of the major design variables. As a vessel is stretched along its length, the prismatic coefficient, longitudinal center of buoyancy, and displacement all change. It is difficult to isolate and examine the influence of each major hull shape parameter on the vessel. This paper describes a computer program that solves this problem by automatically varying the shape of a parent hull while maintaining constant values for the major design parameters. Stephen M. Hollister. (Added: 10-Jan-2002 Hits: 6722)  Rate | Cached | Visit Automatic Hull Variation and Optimization

• Beam vs. Ballast for Seakeeping  
  Does increased beam provide greater comfort in terms of roll motions? Does increased ballast provide greater safety? These are perennial questions which require more than a cursory analysis. Michael Kasten. (Added: 10-Jan-2002 Hits: 7989)  Rate | Cached | Visit Beam vs. Ballast for Seakeeping

• Archive: Best Offshore Cruisers  
  Fuzzy logic sort from data base for "best" cruisers, as defined by the work of noted designers. (Added: 18-Mar-2002 Hits: 5003)  Rate | Cached | Archive

• Boojum's Twin Keels  
  A brief description of the various considerations associated with the use of Twin Keels to solve a specific set of design requirements on a small trawler yacht, including roll reduction. Michael Kasten. (Added: 10-Jan-2002 Hits: 5031)  Rate | Cached | Visit Boojum's Twin Keels

• Archive: Canoe Design  
  Effects of rocker, and other factors, on canoe response. Three designs are analyzed. (Added: 18-Mar-2002 Hits: 4020)  Rate | Cached | Archive

• Choice of Construction Material  
  If you are unsure of the best choice of material for you, this will help you to make the decision. Dudley Dix. (Added: 10-Jan-2002 Hits: 6938)  Rate | Cached | Visit Choice of Construction Material

• Computer Cutting For Boat Building  
  Computer modeling is by far the most efficient means of defining hull form, offering a designer access to powerful analysis tools for assessing stability and performance, as well as a highly accurate means of creating the structural parts and pieces of a boat via computer controlled cutting. For more information about the benefits and cost savings offered by up-to-date computer aided boat design and computer aided boat building check out this article. Michael Kasten. (Added: 10-Jan-2002 Hits: 5463)  Rate | Cached | Visit Computer Cutting For Boat Building

• Computer Prototyping and Development  
  When considering a new vessel, what's the best way to get a preview of the shape? The computer is an enormously useful tool for creating a vessel prototype in order to visualize the shape in a "virtual" 3D environment. What about lofting and fairing? One can then use the computer generated model as a fairing and lofting tool. Michael Kasten. (Added: 10-Jan-2002 Hits: 4906)  Rate | Cached | Visit Computer Prototyping and Development

• Controllable Pitch Propellers  
  Although this article is brief and to the point, it considers several of the issues that arise when asking the question, "What, if any, are the advantages of using a CP propeller on a 'trawler-yacht' or sailing vessels?" Michael Kasten. (Added: 10-Jan-2002 Hits: 4896)  Rate | Cached | Visit Controllable Pitch Propellers

• Cool New Gimmicks... - A Cautionary Tale  
  Here are a few thoughts on what should and what should not be considered desirable features of any new motor vessel. Most particularly, this article addresses the new power vessel vogue: Passagemakers.... and the various gimmicks being offered on them. Michael Kasten. (Added: 10-Jan-2002 Hits: 4468)  Rate | Cached | Visit Cool New Gimmicks... - A Cautionary Tale

• Archive: Cruising Boats Under 100k  
  A list of boats costing less than 100k and making my "Best Offshore Cruisers" list. (Added: 18-Mar-2002 Hits: 4043)  Rate | Cached | Archive

• Archive: Design Basics  
  Definitions of various evaluation factors and ratios used by yacht designers. (Added: 18-Mar-2002 Hits: 5715)  Rate | Cached | Archive