Join Date: Feb 2000
Location: Annapolis, Md
Thanked 164 Times in 133 Posts
Rep Power: 10
Beneteau - Jeanneau
Today, Jeanneau is actually a division of Beneteau (sort of like chevy and oldsmobile being both GM''s.) In the past, my experience with Jenneau was that they generally did not seem as well constructed and detailed as Beneteaus. Beneteaus have generally been designed by world class designers (Frers, Finot, Farr,and Berret)and Jenneaus seemed to be designed by in-house designers. Over the years Beneteau''s designs seem to pretty much follow current design trends, while Jenneaus have been a bit quirkier (for example sticking with IOR like designs long after the IOR typeform was considered less than ideal for cruising boats).
Pans and ribs is a loose description of a form of internal framing used by most of the bigger volume boat builders. There are a lot of ways to build a fiberglass boat but when you look at the boats built by the high volume value oriented boat builders, most hulls are built without coring (with the exception of Catalina who is now starting to build cored hulls). Coring can have larger panel sizes without some kind of additional support but cored or not, most fiberglass hulls have some form of internal framing. Framing helps to stiffen a hull, distribute concentrated loads such as keel and rigging loads, and reduce the skin panel size which helps to limit the size of the damage caused in a catastrophic impact. Framing can be in a number of forms. Glassed in longitudinal (stringers) and athwartship frames (floors and ring frames) provide the most ideal light, strong and very durable solution.
Molded ''force grids'' are another form of framing. In this case the manufacturer molds a set of athrwartship and longitudinal frames as a single unit in a mold in much the same manner as the rest of the boat is molded. Once the hull has been laid up the grid is glued in place. The strength of the connection depends on the contact area of the flanges on the grid and the type of adhesive used to attach the grid. This is a very good way to build a production boat but is not quite as strong as a glassed in framing system.
Another popular way to build a boat is with a molded in ''pan''. This is can be thought of as force grid with an inner liner spanning between the framing. This has many of the good traits of a force grid but has its own unique set of problems. For one it adds a lot of useless weight. It is harder to properly adhere in place, and most significantly it blocks access to most of the interior of the hull. Pans can make maintenance much harder to do as every surface is a finished surface and so it is harder repair the hull, and to run wires and plumbing. Adding to the problem with pans is that many manufacturers install electical and plumbing components before installing the pan making inspection and repair of these items nearly imposible.
Glassed-in shelves, bulkheads, bunk flats, and other interior furnishings can often serve as a part of the framing system. These items are bonded in place with fiberglass strips referred to as ''tabbing''. Tabbing can be continuous all sides (including the deck), continuous on the hull only, or occur in short sections. Continous all sides greatly increases the strength of the boat but may not be necessary depending on how the boat was originally engineered. The strength of the tabbing is also dependent on its thickness, surface area and the materials used. When these elements are wood they can often rot at the bottom of the component where the tabbing traps moisture against the wood.
Of the various framing systems, pan and frames are the cheapest to build but the hardest to repair and the least effective on a pound for pound basis.