name of medication

January 30, 2010

Stiffeners – Deck Beams, Floors, Longitudinal Stringers, Bulkheads, Frames

Filed under: Yachting — Tags: , , , , , — Richard Jordan @ 11:25 am

Hulls need stiffeners to withstand shearing, torsion, tensile, etc. forces. Stiffers break up the long spans of fiberglass into more resilant pieces. Types include bulkheads, floors, frames, stringers, and beams.

Nautor Swan Framing (Surveying Fiberglass Sailboats by Henry Mustin)

Nautor Swan Framing (Surveying Fiberglass Sailboats by Henry Mustin)

Framing Network
Bulkheads are athwartship usually plywood barriers inside the hull. Yachts have multiple including chain-locker, full, half, and sail-locker bulkheads. Builders glue these plywood barriers, and the best quality builders use fiberglass tabbing to structurally connect the bulkhead, deck, and hull. Floors are semi-circular shapes that support the cabin sole. Floors are often of fiberglassed over foam. Frames are athwartship stiffeners inside the sides of the hull. Stringers are longitudinal fiberglassed over foam pieces that go from sterm to stem along the inside the sides of the hull cross-hatching with the frames. Finally, beams are overhead, athwartship stiffeners which support the deck and coordinate with bulkheads or the mast.

Molded Liners
Another option in addition or in place the above are molded liners. Like decks and the hull, these pieces have separate molds with which workers generate a fiberglass structure. Then these liners are tabbed and glued to the hull and bulkheads. Hunter Yachts makes one-piece molded liners which replace stiffening network. This use of a one-piece liner is the extreme version of composite building. It significantly lowers skilled labor costs along with speeding up mass production. There are two problems with molded liners. First, they block access to the hull. To make replairs in the case of a hull break, you have to cutaway the liner to access the hull. And even to normally access the bilge, the molded liner is limiting because of the build-in structures. Second, the glueing process is tricky and has been prone to poor bonding. Placing liners in and glueing them done must be done in one shot. If the mold is misaligned or mistimed, you can have trouble. Molded liners are to some degree to blame for the oil canning and shifting bulkheads on flim flam production boats like Hunters, Catalinas, and Beneteaus. Quality builders like Hylas and Swan do not use molded liners because of these issues.

Stiffeners prevent a hull from breaking up in serious seas. Bulkheads, floors, frames, stringers, and beams are types of stiffeners. The best example of quality supports is the illustration from Henry Mustin’s book, Surveying Fiberglass Sailboats. The picture shows the extremely strong construction of Nautor exemplified by their Swans.

Looking to Purchase or Sell Your Yacht? Please Contact Us.

Our professional and knowledgeable brokers are not only attuned to the ever changing international market but also have thousands of bluewater miles under their belts. We have the experience and integrity to ensure that your purchase of a boat will be a decision that you can be proud of.

Jordan Yacht and Ship Company represents fine sail and power yachts worldwide, both new and used. The majority of our many listings are just minutes away from our office. Call or email for an appointment and let Jordan Yacht and Ship Company help you launch your dreams.

  • chigozie

    what are the concise uses of stiffeners

  • Sorry, I am not sure what you mean? Stiffeners have one use – to prevent a hull from flexing. Please clarify if this does not answer your question.

"We just wanted to take this opportunity to thank everyone at Jordan Yachts for taking such good care of us during the sale of our boat! We found the entire staff to be very knowledgeable and professional. Richard and Ti did a great job with the photos for Yachtworld, Kathy kept us well informed at all times and even took care of the "ships kitties" on survey and sea trial day and special thanks go to Tom Harney and Kevin Bray for guiding us through the whole process and for doing a great job negotiating the sale price for us and handling the survey and sea trial. We would recommend you guys to anyone looking for a yacht broker!" - GS & PS, SV Flying Cloud