Mid Size Power Boats
A Guide for Discreminating Buyers
by David Pascoe
Basic Hull Construction
Overview of Current Hull Issues
Lamination, the Essence of Modern Boat Building
Understanding Laminate Strength
High Technology and Boat Building
Composites and Cores
Ultra High Density Foams
Surveying Cored Hulls
Plywood as a Core
The Essentials of Hull Structure
Structural Grids and Grid Liners
Tabbing and Taping, a Weak Point
Decks & Superstructure
Deck Join Methods
Rub Rail Materials
Windows and Deck Joints
Excerpt: Chapter 4
When we purchase a road vehicle, few of us find it necessary to give any consideration at all to the nature of the chassis, but when it comes to boats it's best not to be so cavalier.
Unlike other vehicles, fiberglass boats don't have a chassis, making it unique among vehicles. As with an aircraft, the boat is the hull which is the frame. This is known as monocoque construction, which refers to the fact that the body and frame are essentially one unit. This chapter gives detailed consideration to all aspects of hull construction.
Of course, I can fully understand why someone who just wants to have fun by buying a boat probably has no desire to go into the esoteric details of hull design and engineering.
My experience with many boat buyers tells me that many people who prefer to spend their hard-earned dollars wisely do make the effort to learn as much as possible.
The basic engineering that goes into good hull design is not particularly difficult to understand and can be illustrated by simple, everyday examples of which we all have some understanding.
Among these are the box, beam and bridge, to which the boat hull has similarities. Boat hulls traveling at high speeds are subject to enormous forces, first because the boat itself is very heavy, secondly because of speed and finally because of waves.
Anyone who has had the experience of a five ton boat launching two feet in the air off of a wave knows what a bone-jarring experience this is.
For the boat hull, this is like doing a belly-flopper off the high diving board. Water has little or no "give" when impacted by a wide flat surface.
Boat hulls are also similar to bridges as they are often hauled with lifting straps and then placed on two blocks under the front and rear of the keel, thereby spanning a long length without the usual support of water it normally gets.
But image the load that is placed on the keel and bottom by the entire weight being placed on just those two points!
When we think about things like this, it is not hard to see why, unless the hull is designed and built exactly right, problems are going to develop.
(Additional spaces are added for easy screen reading.)
- A Guide to Discriminating Buyers
by David H. Pascoe
Publisher: D. H. Pascoe & Co., Inc.
David Pascoe - Biography
David Pascoe is a second generation marine surveyor in his family who began his surveying career at age 16 as an apprentice in 1965 as the era of wooden boats was drawing to a close.
Certified by the National Association of Marine Surveyors in 1972, he has conducted over 5,000 pre purchase surveys in addition to having conducted hundreds of boating accident investigations, including fires, sinkings, hull failures and machinery failure analysis.
Over forty years of knowledge and experience are brought to bear in following books. David Pascoe is the author of:
- "Mid Size Power Boats" (2003)
- "Buyers’ Guide to Outboard Boats" (2002)
- "Surveying Fiberglass Power Boats" (2001, 2nd Edition - 2005)
- "Marine Investigations" (2004).
In addition to readers in the United States, boaters and boat industry professionals worldwide from over 70 countries have purchased David Pascoe's books, since introduction of his first book in 2001.
In 2012, David Pascoe has retired from marine surveying business at age 65.