Fuel savings for small fishing vessels

A manual

by

Oyvind Gulbrandsen
Consultant
Grimstad, Norway

Food and Agriculture Organization of the United Nations
Rome 2012

ABSTRACT

Gulbrandsen, O. 2012.
Fuel savings for small fishing vessels – a manual. Rome, FAO. 57 pp.

The recent sharp increase in the price of fuel has had a major impact on the economics of operating fishing vessels. Fishing boat owners and operators struggle to meet this challenge and ask what measures can be taken to reduce the heavy burden of increased fuel cost. Litres of fuel required per tonne of fish landed varies widely depending on the fish specia and fishing method used. Fuel saving methods have to be tailored to each fishing method and fishery.

This manual aims to provide practical advice to fishing boat owners and crews, boatbuilders and boat designers and fisheries administrators on ways to reduce fuel costs. It focuses on small fishing boats measuring up to 16 m (50 ft) in length and operating at speeds of less than 10 knots. This covers the majority of the world's fishing boats. It also serves as a guide for those involved with fuel savings for small vessels used in support of aquaculture activities. The manual provides information to boat designers and boat builders on hull shape for low resistance and the selection of efficient propellers.

The first chapters of this manual deal with fuel saving measures that can be taken on existing boats without incurring major investment costs. The most effective measures include reducing boat service speed, keeping the hull and propeller free from underwater fouling and maintaining the boat engine. It also suggests that changing fishing methods can save fuel.

The final chapters of this manual provide information regarding the fuel savings that are possible by changing from a 2-stroke outboard engine to a diesel engine, installing a diesel engine, and using sail. Selecting economic engine power on the basis of the waterline length and the weight of the boat is discussed. Advice is given on the choice of gear reduction ratio and of propeller related to service speed, service power and propeller rpm. Data are provided to assist with the design of a new fuel-efficient boat and the selection of an optimum propeller.

The information contained in this manual is accompanied by many illustrations to make the main points more easily understood. Detailed background information is provided in the appendices. The appendices also contain blank tables that may be used to calculate potential fuel savings, cost of engine operation, the weight of a boat and the diameter and pitch of a propeller.

Table of Contents

INTRODUCTION

FUEL USE IN FISHERIES
	The cost of fuel
	Energy use in fisheries
	The fish resource
	Fuel efficiency
	Fuel use – passive fishing methods
	Fuel use – active fishing methods

FUEL SAVINGS ON EXISTING BOATS
	Speed – the most important factor in fuel consumption
	Reducing speed
	Example: fuel savings by reducing speed
	Example: fuel savings by reducing speed
	A boat's waterline length and fuel saving speed
	Keeping the boat bottom clean
	Servicing the engine and giving it air

FUEL SAVINGS FOR TRAWLERS

CHANGING FISHING METHOD TO SAVE FUEL
	Carrying out multiday fishing and mothership operations

CHOOSING A FUEL EFFICIENT ENGINE
	Comparing outboard engines and diesel engines
	Ghana canoe trials with outboar :Exampled and diesel engines
	Would it pay to pur ?chase a diesel engine
	Alternative diesel engine installations
	Liftable propeller installations

USING SAIL TO SAVE FUEL
	Types of sailing rigs
	The use of sail
	Lug sail – checking a boat's stability
	Lug sail details and outrigger canoes

SELECTING A NEW ENGINE TO SAVE FUEL
	Selecting a new engine
	Example: selecting engine power
	Power and speed for fuel savings
	Reading the engine manufacturer's leaflet

SELECTING A PROPELLER TO SAVE FUEL
	Comparing alternative propellers and fuel consumption
	Measuring propeller diameter and pitch
	Selecting a propeller
	Propeller clearances and fairing of the skeg
	Reduced propeller rpm = big propeller = fuel savings

GUIDANCE ON NEW BOAT CONSTRUCTION
	The power and main dimensions of a fuel-efficient boat
	Boat lines for low resistance
	The shape of the bow
	General arrangement
	Fuel savings with outrigger craft and multihull boats

HOW CAN GOVERNMENTS PROMOTE FUEL SAVINGS?

REFERENCES

ADDITIONAL READING

APPENDICES
	1 – Life cycle energy analysis (LCA)
	2 – Measuring fuel consumption
	3 – Calculating fuel savings
	4 – Analysing the cost of engine operation
	5 – Calculating a boat's weight without load
	6 – Calculating a propeller
	7 – Selecting a propeller

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ISBN 978-92-5-107060-4

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