Fisheries Technologies for Developing Countries (1988) / Chapter Skim
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1. Boat Design, Construction, and Propulsion
1. Boat Design, Construction, and Propulsion
Pages 13-48
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From page 13... ...
New vessels should have improved fishing capabilities. Increased seaworthiness and better fuel performance would permit fishing further offshore for previously unexploited species.
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From page 14... ...
Some of the major factors that affect the design of this platform include: Available funds Available materials Skills for building and maintenance Size limitations dictated by water depth or requirement for beaching Distance to fishing grounds Fuel costs Type and quantity of gear used Vessel speed requirements Number of crew, standard of accommodation, cooking facilities Methods of bait and catch preservation Safety features. Usually when a decision is made to introduce new equipment to an existing fishery, the purpose is to fish for a new species or to fish in a new area.
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From page 15... ...
Vessel sizes and designs that have evolved in an area are usually well adapted to the local fishing gear and methods, the range of operations, construction materials, the winds, and local sea conditions. A radical departure from the traditional hull design may not gain local acceptance.
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From page 16... ...
With a crew of 4 and a 20~kg catch, the vessel can achieve a speed of 10 knots with a 20-hp outboard motor. Multihulled vessels, such as catamarans and trimarans, have traditionally been used as fishing boats in the Pacific Islands.
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From page 17... ...
and therefore offer minimum resistance and are easily propelled. Moreover, the stability of multihulIs makes them ideal candidates for sail power.
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From page 18... ...
However, both materials severely limit the hull shape and are relatively shortlived. Wooden logs are heavy and can result in high fuel consumption.
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From page 19... ...
in many tropical coastal regions, suitable boatbuilding timber is scarce and expensive. Another disadvantage is the high degree of skill required to build a wooden boat.
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20 FISHERIES TECHNOLOGIES FOR DEVELOPING COUNTRIES FIGURE 1.5 In Martinique, a traditional planked hull wooden boat rests on the beach; several fiberglass reinforced plastic boats float just off shore.
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From page 21... ...
In Fiji, more than 130 V-bottom fishing boats (8.6 m) have been constructed of plywood.
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From page 22... ...
The product can be a strong, light boat with a life expectancy at least as good as traditional timber vessels. Boat construction by this technique is easy and fast.
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From page 23... ...
Another new boat design constructed by stich-and-glue methods is the ply valiam (figure 1.8~. Traditional grandams are dugouts made from large mango trees.
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24 FISHERIES TECHNOLOGIES FOR DEVELOPING COUNTRIES FIGURE 1.8 In India, traditional vallams are dugout canoes made from large trees. Plywood vallams (left)
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From page 25... ...
25 - go on > lF.~ E_ no ~ ~1 ~ 9-,8 18~: -11 OGL ~ Z ~ ~0 1 d 1 ad 4= ·_ oo _` id ~ 4= ,9 G I._ ~ 4 V L' or d _ .
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From page 26... ...
The hull geometry is such that the veneers can be precut and can be easily mass produced. Each veneer strip does not have to be hand carved to fit perfectly with neighboring pieces.
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From page 27... ...
E`IGURE 1.11 The first step in producing a boat by cold-molding is to staple thin strips of wood to a reusable wooden mold. (Agro-Forest Products Intermediate Technology Associates AFPITA)
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From page 28... ...
A local wood was used for the veneers, but most of the equipment and adhesives as well as the expertise had to be imported. In Tuvalu in the South Pacific, several Constant Camber catamarans transport people and cargo around the atoll lagoons (figure 1.17~.
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From page 29... ...
BOAT DESIGN, CONSTRUCTION, AND PROPULSION 29 FIGURE 1.13 After lamination is complete, the frame can be removed from the mold and the boat finished.
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From page 30... ...
There are five fundamental steps in Ferrocement boat construction: (1) The shape is outlined by a framing system.
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From page 31... ...
Above and below this size range there has not been enough experience to recommend this type of construction. Ferrocement hulls less than about 8 m are usually heavier than comparably sized hubs in wood, steel, FIGURE 1.16 Larger boats can be built using the Constant Camber method by producing half-hull panels and joining these.
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From page 32... ...
or fiberglass. This characteristic also prohibits ferrocement use in multihulled vessels.
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From page 33... ...
have designed and produced more than 1,000 ferrocement vessels Tom shrimp boats to large longline fishing boats. The People's Republic of China has also opted for ferrocement sampans for use on inland waterways.
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From page 34... ...
34 FISHERIES TECHNOLOGIES FOR DEVELOPING COUNTRIES FIGURE 1.19 In Taiwan, plastic tuber are used in single layers to make small rafts or in double layers to produce larger rafts.
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From page 35... ...
The fibers and resin also can be hazardous to the health of the workers. WelI-conceived and financed FRP fishing boats can be successfully introduced in the Third World if they are economically feasible.
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36 FISHERIES TECHNOLOGIES FOR DEVELOPING COUNTRIES FIGURE 1.20 FRP boats have been successfully introduced in Senegal. This boat has largely replaced traditional fishing canoes.
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From page 37... ...
The Bay of Bengal Program has proposed to protect the logs of South India's traditional kat;t;umaran with FRP sheathing. C-FIex C-FIex is a fiberglass planking that can be used to build boats without the standard mold required for fiberglass-reinforced plastic boat construction.
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From page 38... ...
Aluminum is also light, which is another advantage, because it reduces the displacement and results In low fuel consumption. In addition, aluminum shows a high resistance to chafe, has an excellent strength-to-weight ratio, and holds up well under bending stress.
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From page 39... ...
In table 1.1, materials are compared in terms of their use in construction inclu(ling cost, availability, skill level needed, building time, and design flexibility. In table 1.2, these same materials are compared for their performance, including strength to weight, fuel consumption, chafe resistance, service life, and ease and cost of maintenance.
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From page 40... ...
40 FISHERIES TECHNOLOGIES FOR DEVELOPING COUNTRIES TABLE 1.2 Boatbuilding Materials Comparison: Performance St rength Construction Weight Material Ratio Hull Weight Fuel Resistance Consumption to Chafe Longevity Maintenance Logs 5 5 1 3 -- Bamboo 1 1 3 5 -- Wood planking 3 4 2 1-3 4 Strip planking 2 4 2 1-3 4 Plywood sheet 1 3 4 3 5 Stitch and glue 1-2 2 4 3 5 Cold molded 1-2 2 4 1-3 2-3 Constant Camber 1 2 4 1-3 3 Fiberglass laminate 2 3 2-3 1-2 1-2 FRP sandwich core 1-2 1 3-4 2-3 1-2 Composite laminate 1 1 1-3 1-3 1-2 C-Flex 2-4 3-4 2 1-2 1-2 Aluminum 1 1 1-3 1 1-2 Steel 3 4 1 1-3 2-4 Ferrocement 5 5 2-3 3 2 Scale: Strength-Weight: 1 = high ratio Hull weight and Fuel consumption: 1 = low weight and low fuel consumption Chafe: 1 = highly resistant Longevity: 1 = long life Maintenance: 1 = low cost and less difficult to maintain PROPULSION New technologies in propulsion include alternative fuels, alternative engines, and unconventional w~nd-based methods. Alternative fuels include biomass-derived gasoline and diesel-fuel substitutes.
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From page 41... ...
Using coconut-shell-derived charcoal as fuel, producer-gas-powered fishing boats have been tested in the Philippines.* The Intermediate Technology Development Group (ITDG)
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From page 42... ...
,, - - , ~ ,,-.- .,, ,., - ~ I ~ ~ ~ ~ I, If. ~ , FIGURE 1.22 The Intermediate Technology Development Group has begun development of a small steam engine specifically designed to be used in fishing boats in developing countries.
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From page 43... ...
~' /' ~ Downwind ,>~ vent Is open my) Fan sucks alr through vent I Wind direction Forward thrust ~ ~~ ~~:~:~ ~~,~:~:~: ~~:~ ~:~':~ , ~ A; ~ i~,4 ~ ~ 5, ~ ; ~ ~~ ; ~ i , ~ ~ ' ~ ~ 5, ' '-at ~ it; ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ :~ ~W FIGURE 1.23 The 31-m Cousteau windskip ALCYONE can be powered by its turbosails or its diesel engines or both.
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From page 44... ...
Improved vessel designs should not be encouraged in those coastal areas that are heavily overfished, unless the new craft can travel farther onshore and tap stocks that are unexploited at that tone. RESEARCH NEEDS The design of small fishing boats deserves more attention.
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From page 45... ...
Water-resistant glues manufactured from local materials (lignin, for example) would be an economic alternative to expensive imported epoxy or phenolic resins.
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From page 46... ...
1973. Hartlcy's Fcrrocemcnt Boat Building, Boughtwood Printing House, Takapuna North, New Zealand.
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From page 47... ...
Florida Sea Grant Technical Report SGR 60, University of Florida, Gainesville, Florida, USA. Bergeson, L., and C
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From page 48... ...
Department of Ocean Engineering, Florida Institute of Technology, Melbourne, FL 32901, USA Fisheries Technology Service, United Nations Food and Agriculture Organization (FAO) , Via dells Terme di Caracalla, 00100 Rome, Italy (S.
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