Keel design and construction issues are often overlooked until there is a major problem.
With so many Shannon owners sailing in remote and poorly charted areas, keel draft and susceptibility to grounding are paramount concerns. Shannons have internal lead ballast meaning the lead is cast and installed in a keel cavity in the one piece hull. The lead is then encapsulated with fiberglass creating another hull skin over the ballast. On a Shannon, continuous fiberglass filaments from the sheer/deck run down the hull across the bottom of the keel and back up the other side. The lead ballast is held in place by the fiberglass structure of the hull. Unlike Shannon, 90% of the sailboats being built today have lead keels bolted to the bottom of the hull. There can be significant problems for boat owners with bolt-on keels. When a boat goes aground the sheer loads on the keel bolts is tremendous and there is no way to ascertain any damage to the bolts without removing the entire keel. The upward force on the aft top edge of a bolt on keel can create structural damage to the hull. And if the boat with a bolt on keel has a centerboard with a slot in the lead, the soft lead can close around the board when running aground. While bolting the keel on a sailboat is a cost effective construction method, Shannon does not use this technique because of the stated problems for owners going aground. When a Shannon runs aground, and many have in the past 25 years, the damage (if any) can be quickly observed and field repaired easily.
Almost 75% of Shannons have a keel/centerboard configuration. Experienced owners have chosen a centerboard because of the reduced draft benefits. Depth of water is a real issue in practically every part of the world. Carrying over 6' foot of draft on a vessel precludes many of the pretty cruising places like the Bahamas, the Florida Keys, the Chesapeake, northern Europe and many others. The centerboard design and engineering on a Shannon is perfect for exploring. For instance, the centerboard and its pin on a Shannon can be removed without hauling the boat. The lifting mechanism is a simple-to-use and easy-to-maintain cable lead to winch in the cockpit. There are no complicated hydraulic arms holding the board down on a Shannon, so the board is free to swing up if the bottom is encountered. Once again, the keel/centerboard design on a Shannon has been real world tested and proven since 1981.
Copyright © 2006 -2008 Schulz Boat Company