high-velocity spoil 
ah delivery to remote location 
high-pressure 
seawater line 
rolling cutters 
> 
pilot with hydraulic side thrusters = 
to prevent rotation 
rn 
jetted-in steel or concrete casing 
JE soil or sand overburden 
AAR ENN SNS SANE 
— Test 
<li pee et ats 
nae E 
SS wee ha 
| 
Wee IX | x 
K 7 J 
/ Y A, | YS Vm UK 
_ competent rock L----, ----4 competent rock © 
| 0 / } 
JE. 1 é 
WN fi VN ay 
A, 
“0 
Figure 56. Seawater-hydraulic-powered large-hole rock drill for making initial 
penetration into seafloor. 
steel liner 
through silt 
- soil or 
2 = sediment 
initial large 
diameter bore hole 
Figure 57. Method of casing through silt overburden. 
2. 
