se of this circular is to disseminate to vessel designers, owners and
shipyards general information relating to good marine practice when dealing with FRP vessels. It
is intended to provide guidance on various aspects of the design, construction, inspection and
repair of FRP vessels and amplify certain sections of classification society rules. This circular is
based on information from many sources.
2.
PERIODICALS AFFECTED. Navigation and Vessel Inspection Circular No. 3-80 is canceled.
3.
BACKGROUND.
a.
Compared to steel and traditional wood construction, fiber reinforced plastics have not
been in use for a long period of time as a common boat building material. The popularity
and variety of FRP has caused the development to exceed the amount of proper guidance
on its use. Much of the existing Coast Guard guidance applies only to one aspect of
construction or repair, e.g., single-skin displacement hulls with glassed over wood
stiffeners.
b.
Traditional small passenger vessel construction has been relatively basic, so that plan
review, construction and inspection are customary events. However, many current
designs are for complex vessels with various design features, such as sandwich hulls,
combination aluminum and FRP structures, hydrofoils and localized use of high strength
materials, such as kevlar and carbon fiber. Furthermore, the classification society rules of
the American Bureau of Shipping (ABS) and Lloyd's Register of Shipping (Lloyd's)
were developed to be used by those societies' specialized technical experts and surveyors,
and may be difficult to follow for a traditional yacht builder faced with building a
complex vessel or an inspector faced with certificating it.
c.
Repair methods can vary widely but still return a vessel to original strength. However,
there is little formal guidance on Raking reliable repairs. To achieve the level of safety
desired by the Coast Guard, the best methods were investigated and included in this
circular.
4.
DISCUSSION.
a.
Regulations for small passenger vessel construction are found in Title 46, Code of
Federal Regulations (CFR), Subchapter T, Part 177. This part prescribes the rules of
ABS and Lloyd's as acceptable for the structural design and construction of certificated
FRP vessels. Regulations for cargo and miscellaneous vessel construction are found in
46 CFR, Subchapter I, Part 92. Owners of uncertificated vessels may find these
regulations and this guide useful as a safety reference. b.
In addition to ABS and Lloyd's Rules, there are many other classification society
standards, other design standards and existing proven designs. This circular may be used
as a guide to present a vessel for certification which has been designed and built to one
of those other standards. It also covers aspects of survey and repair unique to FRP
vessels.
c.
Enclosure (1) is divided into six chapters:
(1)
Chapter 1., "Structural Design Considerations," discusses the use of the ABS and
Lloyd's rules, methods for gaining approval of designs based on "the five year
rule" of successful operation, other standards, and designs based on detail
calculations.
(2)
Chapter 2., "Plan Submittal Guide," covers submitting plans to the Coast Guard
for approval and discusses many acceptable design details not found in the rules.
(3)
Chapter 3., "Preliminary Construction Tasks," has information on quality
assurance, material property tests, production and inspection personnel safety.
(4)
Chapter 4., "Vessel Fabrication, discusses the actual formation of many
components into a finished vessel.
(5)
Chapter 5., "In-Service Inspections," is information collected from Coast Guard
and industry sources about in-service inspections explaining various fault
conditions, types of deterioration and ways of surveying collisions.
(6)
Chapter 6., "Repairs," discusses many acceptable methods of repair.
5.
IMPLEMENTATION. Owners, operators, surveyors and builders are encouraged to follow the
guidelines set forth in this circular. Although developed with input from industry, classification
societies and experienced inspectors, the Coast Guard realizes that this guide will require
occasional revision to keep pace with industry, and welcomes comments from any source on the
usefulness, adequacy and applicability of this guide. Send comments to Commandant (G-MTH-
3), United States Coast Guard, Washington, DC 20593-0001.
End:
(1)
Notes on Design, Construction, Inspection and Repair of Fiber Reinforced Plastic (FRP)
Vessels Enclosure (1) to NVIC 8-87
2
NOTES ON DESIGN, CONSTRUCTION, INSPECTION
AND REPAIR OF FIBER REINFORCED PLASTIC VESSELS Enclosure (1) to NVIC 8-87
3
GLOSSARY
Aerosol - A term used to describe a broad range of suspensions of solid or liquid particles in air (or in
some special cases other gases). The term includes many other more commonly used and
misused terms, such as dusts, fumes, smokes, mists, and fogs. Small glass fibers which can
remain suspended in air for long periods of times might be referred to as an aerosol. Aerosols do
not include gases or vapors.
ACGIH - American Conference of Governmental Industrial Hygienists. A professional society of
industrial hygienists formed in 1938. Although primarily composed of persons associated with
the government, it is not an official government agency. ACGIH recommendations do not carry
the weight of law unless adopted through official rule making.
American Conference of Governmental Industrial Hygienists
6500 Glenward Ave, Bldg. D-7
Cincinnati, OH 45211-4438
Air Inhibited Resin - A resin that will not fully cure on the surface when exposed to air. These resins may
have wax introduced into the resin which will migrate to the surface, seal the surface and allow
the resin to cure.
ANSI - American National Standards Institute. ANSI is a nonprofit organization whose bylaws provide
for membership from national trade, technical, professional and labor groups, firms from
commerce and industry, government, consumer groups and similar organizations. It is a national
clearing house for standards supported by a national consensus.
American National Standards Institute
1430 Broadway
New York, NY 10018
Approving Authority - For a vessel certificated by the Coast Guard to carry more than six passengers,
this will be the cognizant OCMI, the Marine Safety Center or Commandant who approves the
design of a vessel.
ASTM - American Society for Testing Materials. ASTM is a scientific and technical organization formed
for the development of standards on characteristics and performance of materials, products,
systems and services, and the promotion of related knowledge. The ASTM address is:
American Society for Testing Materials
1916 Race Street
Philadelphia, PA 19103
Bedding Compound - White lead or one of a number of commercially available resin compounds used to
form a flexible, waterproof base to set fittings. Enclosure (1) to NVIC 8-87
4
Bonding Angles - An additional FRP laminate, or an extension of the laminate used to make up the
joined member) which extends onto the existing laminate to attach additional items such as
framing, bulkheads and shelves to the shell or to each other.
Cabin Sole - See Hull Liner.
Ceiling Concentrations - OSHA Ceiling concentrations, found in 29 CFR 1910.1000, are concentrations
which, in addition to the PEL are not to be exceeded during the work shift even for a brief
period. For a few chemicals (including styrene) the ceiling can be exceeded up to a "peak" value.
The duration of excursions to these peak values are strictly limited and the daily exposure must
still be within the PEL average.
Chain Plates - The metallic plates, embedded in or attached to the hull, used to evenly distribute loads
from shrouds and stays to the hull of sailing vessels.
Chemical Bond - A bond formed by the chemical cross-linking of the resin polymer during its cure. A
primary bond between laminates is a chemical bond. A secondary bond is an adhesive bond to an
already cured laminate where the resin has cured to the degree that polymer cross-linking is no
longer possible when the next laminate is applied.
Chopped Strand Mat - Fiber reinforcement of short randomly oriented fibers to achieve strength in all
directions of a laminate as opposed to woven rovings, knitted or unidirectional fabrics which
achieve maximum strength in discrete directions of a laminate.
Cored FRP - See Sandwich Construction.
Fire Retardant - Shipboard materials such as FRP, fabrics, paddings, and draperies, which have a
considerably higher degree of flammability than noncombustible materials, yet maintain a degree
of protection higher than that of non-fire retardant materials of similar construction.
FRP - Fiber Reinforced Plastics. FRP has been used alternatively to mean fiberglass reinforced plastics,
fiber reinforced plastics and many other reinforced plastics. In this guide, it means plastics
reinforced with fibers or strands of some other material.
Ganged Woven Ravings - An FRP laminate consisting of adjacent layers of woven rovings without the
normally applied layer of chopped strand mat between layers.
Glass Tabbing - Same as Bonding Angles.
GRP - Glass Reinforced Plastic or fiberglass.
Hull Liner - A separate interior hull unit with bunks, berths, bulkheads, and other items of outfit
preassembled then inserted into the hull shell. A liner can contribute varying degrees of stiffness
to the hull through careful arrangement of the berths and bulkheads. Enclosure (1) to NVIC 8-87
5
IDLH - 'Immediately Dangerous to life or Health - A maximum concentration of a hazardous substance
to which a person c