APPLICATIONS 
Potential applications for placing concrete in the deep ocean are 
basically in three areas: in situ construction of anchors and foundations 
for fixed ocean facilities, in situ hardening of structures or objects 
on the seafloor, and containment of hazardous or polluting substances 
for environmental protection. Such applications would require portland 
cement concrete to be placed underwater in quantities of hundreds and 
thousands of cubic yards in water depths as great as 20,000 feet. 
The capability to construct and install very large anchors and 
large seafloor foundations and structures in deep water has been identi- 
fied as a near and mid-range requirement in a recent study of capabili- 
ties needed by the Navy for fixed ocean facilities (Ref 1). A military 
task which requires this technology can arise quickly. Conversely, if 
the technology is available and known to planners and designers, they 
may conceive and implement tasks which otherwise they may dismiss as too 
advanced. 
The hardening and containment applications also may arise at any 
time. Thus, there is a need to be ready with the appropriate methods 
and means to minimize the consequences or problems that could develop. 
The capability of concrete placement is a "tool" which should be available. 
In Situ Seafloor Construction 
Future requirements have been identified for massive deep ocean 
anchors with holding capacities on the order of 2 to 20 million pounds 
for fixed ocean facilities (Ref 1 and 2). The most practical way to 
provide such large holding capacities in most deep ocean seafloors is to 
use very large deadweight anchors. In certain hard seafloors, the large 
anchor forces may be best provided by clusters of piles drilled into the 
bottom and connected together with large pile caps (Ref 2). 
A 20 million-lb capacity deadweight concrete anchor would have a 
submerged weight of about 40 million pounds and thus be about 160 ft in 
diameter by 20 ft thick. This is comparable to the quantity of concrete 
in a large building mat foundation or a bridge pier but is small compared 
to a concrete offshore oil platform or a deadweight anchorage for a 
suspension bridge cable. 
Methods do not presently exist for the deployment of the large 
deadweight anchors since the loads are beyond the capacity of existing 
heavy lift equipment. A number of drill ships exist that can lift about 
one million pounds in deep water. A few crane barges are available 
rated at six million pounds for surface or shallow water lifts. One 
ship in the world, the Glomar Explorer, has had the capability to lift a 
design load of about eight million pounds from a depth of 17,000 ft, but 
is currently being converted to an ocean mining ship. Two or three 
other recently developed mining ships have deep water lift capacities 
greater than the drill ships' but less than the Glomar Explorer's. 
