NATURE AND EXTENT OF FOULING OF SHIPS' BOTTOMS 



By J. Paul Visscher 

 For the Bureau of Construction and Repair, U. S. Navy Department 



CONTENTS 



Pago 



Introduction 193 



Statement of the problem 193 



History of the problem 195 



Methods 198 



Nature of fouling 198 



Extent of fouling 203 



Effects of fouling 213 



Factors that determine fouling 215 



Relation of duty of ship to fouling. . 215 



Hull and contour of ship 217 



Length of period between dry- 

 dockings 219 



Waters cruised 223 



Seasons and rate of growth 225 



Seasonal periodicity 226 



Rate of growth 228 



Fresh water 228 



Historical data 228 



Data from ships 228 



Experimental data 229 



Poison paints, metals, and surface 



films 230 



Page 



Factors that determine fouling — Contd. 

 Poison paints, etc. — Continued. 



Poison paints 230 



Effect of poison on larval 



barnacles 234 



Surface films 236 



Metals 237 



Light and colors 238 



Submerged test panels 239 



Submerged colored tiles 242 



Woods Hole, Mass 242 



Beaufort, N. C 243 



Reactions of the cyprid larvae of 



barnacles to spectral colors 244 



Reactions of larval barnacles to 



light at time of attachment 246 



Process of attachment of the 



larvae of barnacles 246 



Discussion and conclusions 247 



Summary 248 



Bibliography 249 



INTRODUCTION 



STATEMENT OF THE PROBLEM 



Fouling of ship's bottoms is an accumulation of plant and animal organisms, 

 which attach and grow on both wooden and metal ships. This accumulation of 

 material consists of many species of animals and plants, which find the bottom of a 

 vessel a favorable place of abode. All who have ever been at a seacoast have noted 

 the crowded growths of "seaweed," barnacles, "moss," corals, and the like that 

 frequently cover almost all structures that are either totally or partially submerged 

 and that afford a place of attachment. It is this type of growth, in the main, that 

 attaches to the hulls of boats and causes them to be "fouled." In its broadest 

 usage, this word covers not only the effects of organisms that grow on ships, but 

 also of those that burrow into them (in the case of wooden vessels), and has even 

 been used to include the deleterious effects of corrosion on metal ships. In this 

 paper only the first and original idea of this term will be considered, inasmuch as 



193 



