The first is that slip rings are implicit in the development of tethering technology, resulting in an ROV's ability to function at great depth. The second involves operation of floating production systems. ROVs Greater operating depths require longer and stronger ROV cables. This places new demands on slip rings in providing fiber optic telemetry links. Fiber optic transmission is now in widespread use, as the attenuation in electrical conductors is unacceptable at ranges in excess of a few kilometers.
Optical fiber has a vital size advantage over insulated electrical conductors.
It is also lighter in weight. As umbilicals get longer, they weigh more and create more drag or resistance in the water. This requires more area for strength members in the cable cross-section, which in turn would make the cable even heavier and larger in diameter. In conjunction with the use of advanced materials such as aramid fiber in the cable strength members, the size and weight saving achieved by using fiber optics for signals allows marine cables to remain manageable even in lengths of 10 kilometers or more. FPSOs Floating production systems, including FPSOs, have tended to replace gravity-based structures in oil and gas fields located in deeper waters.