Electro-optical Umbilical for 6000m water depths

FULL JURNAL

At 6000m depths, special attention has to be paid to cable weight and outer diameter, as they are the main contributors to the mechanical forces acting on the top section of the cable. At the bottom section, the hydrostatic pressure has to be considered. It is also important to minimise the cable outer diameter in order to reduce the hydrodynamic forces acting on the cable. On the other hand, the ROV power consumption limits the acceptable voltage drop. This leads to an evaluation of cable heating vs. Cu cross-section.

Power conductors
There are several considerations regarding choosing the right power conductor. The overall
target of reducing weight and dimension encourages low cross section power conductors. However, the required voltage at the load and the line current leads to a maximum acceptable voltage drop. Also, cable heating can be significant if several cable layers remain on the winch. The cable temperature depends on the heat transfer through the different materials, and might lead to cable degradation.