name of medication

February 2, 2010

Mast Step – Keel, Deck Stepped, Compression Post, Knee, Athwartship Beam

Filed under: Yachting — Tags: , , — Richard Jordan @ 1:26 pm

Masts are either keel or deck stepped.

Keel, Deck Step Masts

Keel, Deck Step Masts

Keel Stepped
Keel stepped boats have a mast which goes down through the deck and to a mast step at the keel. This design is the classical way and the most secure way to secure the mast. Masts must dissipate two types of forces: bending and pumping. By letting the mast go through the deck, a keel stepped boat minimizes the deck’s vulnerability. Bending forces distribute over a longer distance from the keel to the deck. Pumping forces have a solider foot, the keel ballast, to negate them.

While the keel stepped mast minimizes deck pressure, the mast must interact with the deck. To further withstand bending forces, keel stepped masts use knees which connect the deck to the mast or tie rods which support the deck by connecting it to the step. Rubber wedges structurally separate the mast and deck around the collar, the area where the mast passes through the deck. The wedges allow the mast to pump up and down slightly without flexing the deck. Because essentially the collar is a hole in the deck, often water seeps by the wedges. Sailors must carefully keep the area cocked or the moisture can rot the deck. Around the mast, builders should avoid using balsa core.

The bilge is another vulnerable area to rot. Bilge water can damage the mast and step. The step should be raised and kept dry.

Deck Stepped
Deck stepped boats have a mast which does not go through the deck. Instead the mast step is right at the deck level. This arrangement is a modern idea that frees up space below and with proper engineering safely secures the mast. To prevent deck damage from the bending and pumping forces, builders install a compression post from the bottom of the mast to the cabin sole. Like a keel stepped mast, this “jack post” transfers forces and limits the moments on the deck. A floor support in the bilge under the post structurally attaches to the keel. This floor support can rot and cause the deck to sink. The owner may tighten the shrouds without realizing the underlying problem.

Masts are either keel or deck stepped. A keel stepped version is traditionally seaworthy while a deck stepped mast frees up room below. With the advanced engineering of today, well built boats can be either keel or deck stepped and have safe rigs.

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.

"Dear Jordan Yachts - I write with great appreciation for all that Tom Harney has done for us. My wife and I have just purchased our first cruising boat and we plan to sail for a couple of years in the Caribbean with our three small children. Tom has been so much more than a broker and his experience, dedication and commitment to Jen and I have gone way beyond our expectations. In many ways, he is like an “adopted” father who is looking out for me his “adopted” son as we moved into uncharted waters. There have been countless examples of his "above and beyond" execution from our first phone call to ultimately closing on the boat. For example, the official closing of the paperwork could have been the closure of the transaction but to Tom, he was much more interested in seeing that we properly outfitted the boat and provided many recommendations from his 30+ years in the marine industry of who to use and what equipment is needed. In addition, he personally got involved in managing the outfit of the boat well beyond the official closing. Words can't express our appreciation and I would welcome any inquires from potential clients as to the positive experience with Tom Harney - On behalf of my family, a sincere thank you ---" - Marc Konesco s/v adagio