Cargo Ventilation: A Guide to Good Practice

This unique illustrated guide for masters, ships' officers and others associated with the carriage of cargo explains how to avoid problems and disputes arising from incorrect usage of natural and mechanical hold-ventilation systems on cargo ships. Incorrect use of ventilation can lead to extensive cargo damage from ship's sweat, cargo sweat, rainwater, seaspray, overheating or excessive cooling. The guide addresses the key cargo ventilation questions of why, when, what and how, with particular emphasis on the application and pitfalls of the dew-point and three-degree rules. The guide works on various levels, with a quick reference section supplemented by practical guidance and considerations, plus a scientific background for those wishing to understand the underlying principles.

Table of Contents:
Chapter Page1. INTRODUCTION 3Why ventilate? 3Safety 4How to use this guide 5Glossary of terms 62. QUICK REFERENCE 7When to ventilate 7Cargoes that may require ventilation 73. PRACTICAL GUIDANCE 10What is sweat? The simple explanation 10Hygroscopic and non-hygroscopic cargoes - know your cargo 14Finding the dew point 14Three-degree rule - for hygroscopic agricultural cargoes only 17How effective is ventilation? 18When should cargo be ventilated? 20When should ventilation be stopped? 21Types of ventilation system 214. PRACTICAL CONSIDERATIONS 25Stowage 25Dunnage 26Recent developments in the rice trade 28Cargoes that do not fit the rules 29Equipment for measuring the dew point 29Myth or truth? 315. SCIENTIFIC BACKGROUND 35Air, moisture and relative humidity 35Relative humidity and dew point - an example 38How much condensation is produced? 38Hygroscopic cargoes 39Scientific rational for ventilation 39INDEX 43

About the Author :
David Anderson (left) is an experienced master mariner and a partner of Brookes Bell. He has a BSc in Nautical Studies and a postgraduate Diploma in Management Studies. He joined Brookes Bell in 1982 after 17 years at sea, mainly in general cargo liners, where he rose to the rank of chief officer. In addition to problems involving cargo ventilation, his particular areas of interest are personal injuries and fatalities, carriage of timber and logs, and hold-cleanliness disputes. Daniel Sheard is a scientist and a partner of Brookes Bell. He has a Masters degree in Microbiology and a PhD inPhysics/Applied Mathematics. He joined consulting scientists Jarrett Kirman in 1996, which merged with Brookes Bell in 1998. He specialises in the scientific aspects of the carriage, storage and deterioration of a wide variety of commodities including grain cargoes, whole oilseeds, derived agricultural products, fertilizers, liquid cargoes, minerals, chemicals and refrigerated goods.