ay re 
Oe ES —_t__ 
-—_ ——— 
power line from ocean surface 
power center 
—  —— 
> . . 
= fouled power line 
| 
inet BE eis cae 2 
= 
ay Rie isis has la 
mma = 
Se 
Figure 27. Potential problem in working a tethered seafloor machine. 
To insure development of the most reliable total system possible, 
it is planned to use power in the minimum number of forms practicable. 
Because of the torque-limiting characteristics of hydraulic motors, actuators, 
and controls, it appears that a maximum use of hydraulic components will 
be advisable. |f power is supplied to the work site and to the working plat- 
form through an electrical cable, a central hydraulic pump driven by a totally 
sealed electric motor will be needed. Whether the hydraulic system will be 
filled with a petroleum base hydraulic fluid or uses filtered seawater is prob- 
ably of small consequence, except that precaution must be taken with the 
27 
