techniques for sampling in sufficient quantity and 
quality require further development. During the 
decade of 1970-1980 there will continue to be 
many gaps in the required technology. The great- 
est current need is to characterize the geology of 
our Continental Shelf as it is critical to planning 
economic exploitation. It is anticipated that most 
major technical problems could be solved by the 
recommended decade of aggressive technological 
development during the 1970's. 
Sand, gravel, and oyster shell dredging (local 
enterprises oriented to local situations), and sulfur 
extraction (related to petroleum in its recovery 
techniques and economic problems) essentially 
comprise the mining industry on the U.S. Conti- 
nental Shelf. There are, however, successful sea 
mining operations in other parts of the world 
where the legal and economic climate is more 
favorable and where the existence of minable 
deposits has been established. Nevertheless, there 
is or has been activity involved in exploring for 
gold off Alaska (depths of almost 200 feet), 
phosphorite off North Carolina and California 
(depths of almost 600 feet), and manganese and 
phosphorite nodules and crusts on the Blake Pla- 
teau (depths of 2,400 to 3,600 feet) and at even 
greater depths, especially in the Pacific Ocean. 
Except for coal and iron, mined from tunnels 
started on land and extending out under the 
seabed, there is essentially no sub-bottom mining 
of solid minerals. Present mining concentrates on 
bottom deposits that require dredging operations. 
Of dredges in current use, a modified air lift 
hydraulic dredge presently has the potential to 
operate to 1,000-foot depths; conceptual designs 
have been made of suction dredges capable of 
recovering nodules at 4,000-foot depths. 
Mining deep sea manganese nodules has at- 
tracted serious evaluation and interest. However, 
mining technology for economic exploitation of 
deep sea nodules does not exist. The problem is 
not only that of economic recovery but that of 
economically separating the elements from raw 
nodules. 
Small scale sampling of the deep sea floor to 
locate mineral deposits and secure samples for 
specific laboratory analyses only recently has been 
conducted. Sampling of the deep sea floor still is 
so time consuming that a discouragingly small 
number of samples come from a day’s work. 
Of various design studies made on nodule 
recovery, all require making use of advanced 
undersea technology. The problems of providing 
sufficient power to lift thousands of tons of 
minerals from great depths; the need for ultra- 
high-strength, corrosion resistant hoisting cables; 
the requirement to design long, flexible pipes or 
hoses for deep water that can withstand the ocean 
current drag and the resulting bending and shear- 
ing stresses; and the problem of three-phase-flow 
through such long pipes are typical of basic 
engineering problems. 
The task of extracting ores from rocks beneath 
the continental shelf is an order of magnitude 
more difficult than that of dredging shelf depth 
bottom deposits. Yet this type of mining justifies 
continuing attention. In contemplating sub- 
bottom mining far from land, mining through a sea 
floor entrance must be considered. Ultimately, 
such objectives may be accomplished with sea 
floor entrance and undersea transfer capabilities, 
much of which may result from technology 
developments funded under military programs. 
The shaft required for mining production is 
much larger than a mining core drill hole or a 
petroleum production hole. Furthermore, to bring 
a mine located by coring into production requires 
the cutting of many thousands of feet and even 
miles of costly tunnels and underground excava- 
tions radiating from the mine shaft. In addition, 
the process of bringing up tons per day of solid 
minerals requires very expensive hoisting equip- 
ment. 
In conclusion, deep ocean mining will require 
development of many new types of equipment 
heavily dependent on marine technology advances. 
Possible examples include: (1) submarine crawlers 
and bottom hovering vehicles for exploration and 
recovery of deposits, (2) stationary or neutrally 
buoyant platforms, (3) drilling rigs on the ocean 
floor, (4) submarine dredges, (5) high capacity, 
low cost vertical transport systems, and (6) high 
capacity equipment for horizontal transfer. 
Recommendations: 
Many mining spokesmen have indicated that indus- 
try will undertake the costs of detailed surveys and 
development of mineral recovery technology. The 
Government’s role should be to provide the 
following: 
VI-189 
