how critical information relating to underwater 

 technology can best be made available to industry. 



Ocean mining equipment and installations 

 should be capable of functioning uninterruptedly 

 and of enduring years of adverse sea conditions. 

 This requires not only durability in the face of 

 tremendous extremes of weather and sea condi- 

 tions but also resistance to the powerful corrosive 

 forces of sea water and organisms. The resistance 

 to sea water corrosion of materials from which 

 tools and machinery might be built is not well 

 known. 



Recommendation: 



A more comprehensive program for materials 

 testing, data reporting, and interpretation of test 

 data should be organized. An advisory board of 

 marine materials authorities from industry, uni- 

 versities, private institutions, and Government 

 should be established to guide the programs of the 

 various agencies for materials testing. 



D. U.S. Capabilities To Use Marine Resources 



1. Unconsolidated Deposits 



Although the placer mining industry in this 

 country has been much neglected during the past 

 25 years the problems of working in the nearshore 

 areas have been well defined by the operations of 

 the offshore oil industry during the same period. 

 Mining problems will relate mostly to motion in 

 surface platforms, excavation, control, materials 

 handUng, and beneficiation. Marine corrosion and 

 biological fouling are important aspects which wiU 

 become more obvious problems as operations are 

 developed. 



It is a common assumption that dredging or 

 other types of seafloor mining may be a major 

 source of pollution and that mining will be 

 generally incompatible with other resources and 

 uses of the marine environment. However, no 

 definitive study of this problem has been made. 

 Meaningful economic evaluations of offshore hard 

 mineral resources will probably be impossible in 

 the absence of reliable information on the amount 

 and kinds of pollution that may result from the 

 extraction of mineral resources. 



Recommendation : 



A comprehensive study should be made to de- 

 termine the amount and kinds of pollution that 

 may result from seafloor mining operations and 

 the potential effects of such pollution on the living 

 resources and on the overall quality of the marine 

 environment in the area where mining is done. 

 Such a study should also determine what benefi- 

 cial effects other than mineral production might 

 result from sub-sea mining. 



The prospective capability to carry out large 

 scale exploitation of materials from the deep sea 

 floor using totally submerged systems is probably 

 10 to 15 years distant, depending on the incentive. 



a. Hypothetical Offshore Dredging Operations in 

 Shallow Water Two hypothetical dredging opera- 

 tions are evaluated (see Appendix C for detailed 

 evaluations) to bring some of the problems of 

 submarine mining into clearer focus. One is a gold 

 operation in Norton Sound off Alaska where 

 severe weather conditions prevail during a large 

 part of the year, limiting operations to 185 days 

 out of the year; the other assumes a gold operation 

 in waters where less severe environmental condi- 

 tions prevail, as off the coast of Oregon where 

 operations might be conducted 362 days a year. 

 Basic assumptions made about both deposits are: 



—They are located one mile offshore; 



—The combined depth of water and deposit 

 thickness does not exceed 150 feet; 



—The deposit is amenable to standard bucket line 

 dredging methods giving a recovery factor of 90 

 per cent; 



—The average grade of the deposit is 75 cents per 

 cubic yard, with reserves equal to the 20 year life 

 of the dredge; 



—The estimates are basically engineering cost 

 valuations. 



Increasing the working time reduces the oper- 

 ating costs considerably. In Norton Sound costs 

 are 22.9 cents per cubic yard for a 185 day per 

 year operation, whereas costs are 16.5 cents per 

 yard on a sheltered coastline where operations can 

 be conducted 362 days per year. 



VII- 110 



