CIMC Raffles held last week naming ceremonies for the OOS Gretha and OOS Prometheus semi-submersible drilling rigs, built at its yard in Yantai, China, and due to work for Petrobras offshore Brazil. The two units were designed and built by CIMC Raffles.
Above : The OOS Gretha, at Yantai, Photo : courtesy CIMC Raffles.
The OOS Gretha is 137.5m-long, 81m-wide, 39m deep (base line to main deck), with a maximum variable load of 7070-ton.
It can accommodate 618 people, has a DP3 system with Thrustmaster Azimuthing, Underwater (dis)mountable Thrusters, and was classed by ABS. CIMC Raffles said it is the first asymmetric semisubmersible unit without bracing in the world. This reduces the towing resistance and dynamic positioning load, improving sailing speed from an average 8 knots to more than 12 knots.
The asymmetric pontoon outline, with pneumatic de-ballast system, also aids quick ballast adjustment, to suit heavy lifting operation. Continue reading “OOS Gretha and OOS Prometheus semisubmersible drilling rigs naming ceremonies at CIMC Raffles, China” »