Cathedral hull
Encyclopedia
A cathedral hull is a hull
shape used in modern boats, usually power-driven. It can be thought of as a kind of vestigial trimaran
in which the center hull has two smaller side hulls which are so close to the main hull that there is no longer any open space. In fact a cathedral hull is a vee-bottomed boat with sponsons which extend almost as far forward as the main hull. The airspace between the hulls may be very small or nonexistent—a good example would be the classic "Boston Whaler 13" which is nearly a flat-bottomed scow at the stern.
Depending on the proportions of the side skirts and the depth of the main hull, the cathedral hull can approach the handling characteristics of either the Hickman sea sled
, or the deep-vee hull. (Worth noting is that the naval architect first credited with the successful use of the deep-vee hull form, C. Raymond Hunt, also invented the Boston Whaler
).
The term "cathedral hull" refers to the resemblance of a section through an inverted boat to that of a medieval cathedral
.
The cathedral hull configuration tends to result in a very broad bow; many such boats are completely rectangular. This provides the maximum cargo or working space for a given length and beam. The hull shape is also very stable compared to a conventional v-shaped bottom, and in either light chop conditions or above 40 knots or so is faster than a flat bottom, for the same weight, length and beam.
Cathedral hulls became popular in the 1960s and 1970s, when the use of fiberglass
made economical production of this hull-form possible. The undesirable aspects of the cathedral hull are greater weight and cost, pounding in rough water, and a boxy appearance. Their advantages include high waterplane area at rest (good initial stability
) a dry ride in light chop, and reasonable fuel economy at planing
speeds. In exposed waters this hullform has been almost totally replaced by the modified-vee and deep-vee hull forms. After a period of reduced popularity, they live on in modified form as "deck boats" which are very popular in the inland lakes and rivers, especially in the south and midwest.
Hull (watercraft)
A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.The structure of the hull varies depending on the vessel type...
shape used in modern boats, usually power-driven. It can be thought of as a kind of vestigial trimaran
Trimaran
A trimaran is a multihulled boat consisting of a main hull and two smaller outrigger hulls , attached to the main hull with lateral struts...
in which the center hull has two smaller side hulls which are so close to the main hull that there is no longer any open space. In fact a cathedral hull is a vee-bottomed boat with sponsons which extend almost as far forward as the main hull. The airspace between the hulls may be very small or nonexistent—a good example would be the classic "Boston Whaler 13" which is nearly a flat-bottomed scow at the stern.
Depending on the proportions of the side skirts and the depth of the main hull, the cathedral hull can approach the handling characteristics of either the Hickman sea sled
Hickman sea sled
The Hickman Sea Sled is an inverted vee planing hull invented by Albert Hickman. The Sea Sled is a direct forefather of the modern high speed catamaran or tunnel hull....
, or the deep-vee hull. (Worth noting is that the naval architect first credited with the successful use of the deep-vee hull form, C. Raymond Hunt, also invented the Boston Whaler
Boston Whaler
Boston Whaler is a boat company that builds foam filled fiberglass boats. Boston whaler was founded in 1958 by Richard T Fisher, and is still in business today.-History of the Design:...
).
The term "cathedral hull" refers to the resemblance of a section through an inverted boat to that of a medieval cathedral
Cathedral
A cathedral is a Christian church that contains the seat of a bishop...
.
The cathedral hull configuration tends to result in a very broad bow; many such boats are completely rectangular. This provides the maximum cargo or working space for a given length and beam. The hull shape is also very stable compared to a conventional v-shaped bottom, and in either light chop conditions or above 40 knots or so is faster than a flat bottom, for the same weight, length and beam.
Cathedral hulls became popular in the 1960s and 1970s, when the use of fiberglass
Fiberglass
Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...
made economical production of this hull-form possible. The undesirable aspects of the cathedral hull are greater weight and cost, pounding in rough water, and a boxy appearance. Their advantages include high waterplane area at rest (good initial stability
Stability conditions (watercraft)
Stability conditions is the term used to describe the various standard loading configurations to which a ship, boat, or offshore platform may be subjected. They are recognized by classification societies such as Lloyd's Register, American Bureau of Shipping and Det Norske Veritas...
) a dry ride in light chop, and reasonable fuel economy at planing
Planing
Planing may refer to:* Planing or hydroplaning, a method by which a hull skims over the surface of the water* Hydroplaning , a loss of traction caused by a layer of water between the tires and the road surface...
speeds. In exposed waters this hullform has been almost totally replaced by the modified-vee and deep-vee hull forms. After a period of reduced popularity, they live on in modified form as "deck boats" which are very popular in the inland lakes and rivers, especially in the south and midwest.