This paper discusses various aspects of the structural design of fiber reinforced plastic (FRP) offshore racing and cruising yachts. Items discussed are materials, laminates, structural details, and rudders and keels. Emphasis is on those aspects that have been found to deserve attention in that they: are not covered in specific detail in the ABS Guide for Building and Classing Offshore Racing Yachts; are covered but are sometimes not complied with; or are outside the scope of the Guide.
The approach is to review the standard and advanced composite materials as they are currently used for ocean racing yachts and for ocean cruising/racing yachts. Various terms and aspects of laminate design are discussed. By their nature this is particularly applicable to advanced composites for which it is not only necessary to make fullest use of their advantageous properties but also to be aware of and consider in design their less obvious restraints.
Typical structural arrangements are mentioned, structural design and structural detail are discussed, again with emphasis on the advantages of the various materials and details, and the pitfalls to be avoided. Due to their importance rudders and keels are reviewed in detail, focusing on certain features that could be or have been known as a source of past problems.
The ABS Guide for Building and Classing Offshore Racing Yachts is briefly referred to in its role of providing the standards for the structural design of ocean racing yachts and in its applicability to cruising racing yachts.
For those interested, an appendix gives a brief history of the Guide and the role of the Offshore Racing Council and ABS in its development and current use.