CONCEPTS FOR DRILLING AND EXCAVATING IN 
AND BELOW THE OCEAN BOTTOM 
Technical Report R-725 
YF 38.535.003.01.006 
by 
E. J. Beck, T. L. Culbertson, P. J. Daly, 
H. A. Gaberson, and A. L. Scott 
ABSTRACT 
In support of planned development of construction systems for 
precise excavation and drilling in the deep ocean floor, a study of the poten- 
tial problems which might be encountered has been made. Two Deep Ocean 
Technology (DOT) efforts are considered, and two major subsystems are 
described. The first subsystem is a seafloor excavator which can shape the 
ocean floor, prepare trenches and drill shallow foundation holes. To avoid 
the problems of man in undersea environment, this equipment will be 
unmanned, and remotely controlled by computer and/or numerical tech- 
niques. The primary work function will be similar to a conventional milling 
machine, with similar ability to bore shallow holes. The second subsystem 
is for penetration of ocean bottom rock with large holes, sealing off the 
cavity with a prepared steel structure, dewatering, and lateral tunneling at 
one-atmosphere pressure. Initial penetration will be by equipment similar 
to large mining or tunneling moles; recent technology in rock disintegration 
may allow use of a less massive machine with low thrust and torque. 
Approved for public release; distribution unlimited. 
Copies available at the National Technical Information Service 
(NTIS), Sills Building, 5285 Port Royal Road, Springfield, Va. 22151 
