Page 116: of Offshore Engineer Magazine (Sep/Oct 2013)

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of the separation performance, on- instead of fberglass wool. reference systems, giving Gryphon and offshore, specifcally around the The vessel’s fare tower was going Alpha triple redundancy. build-up of emulsions, so early proac- to be replaced, but it was refurbished, The thruster control system now has tive action can be taken, says Alan and additional lights installed. full redundancy, so that if there is any

Simmonds, controls engineer. New life boats, adhering to recently single failure, no matter how signif-

North Sea

The new second-stage separator and increased personnel size specifcations, cant, the vessel will have suffcient the HIPPS, were the result of a high were also installed. thruster capacity to remain on station.

level of design work, says Neal Gray, In a situation such as a Force 8 gale, head of technical assurance, Maersk. the power systems can be split, sepa-

Marine systems “The whole system is the way we Work had already started on replacing rating process power (two Solar Mars control the risk of overpressure in the the Gryphon Alpha’s dynamic posi- gas turbines) from marine systems (fve frst vessel in the process train,” he tioning (DP) systems, with an upgrade marine 3MW diesel generators). The says. “With the HIPPS system we can to the Kongsberg thruster control and marine systems can also be split, so monitor it and, if it happens, shut it vessel automation system. The vessel that at least two thrusters are always down quickly and then control how had a Kongsberg Simrad vessel control available. The system went through a fast it starts up.” and Simrad dynamic positioning full failure mode analysis and sea tri-

The Gryphon Alpha’s Lintott direct system, which has been upgraded to als, prior to deployment. hydraulic well head control panel, K-Pos thruster control system, K-Chief Rolls Royce at Ålesund, Norway, which consisted of a manually oper- vessel automation system and K-Safe also overhauled, recertifed, and reft- ated panel inside the turret and had safety module, or emergency shut ted Gryphon Alpha’s thrusters. become obsolete, was removed. Its down and fre and gas system. The functionality was absorbed into the upgrade to K-Safe included replacing

Tanks existing electric-hydraulic system, the vessel fre detection system with a The FPSO has a storage capacity of feeding into a master control sta- new Autronica fre panel and detec- 525,000 bbl in 12 inert, gas-blanketed tion, that has greater fexibility to be tors. Maersk also upgraded the position cargo tanks, with offoading via a 20in. reconfgured. hose to shuttle tanker. These, and the

Obsolescence also ballast tanks and anodes, were cor- resulted in a new cargo roded and were due to be refurbished system, Kongsberg’s offshore. Instead, they underwent a

K-Gauge. The cargo more thorough inspection in drydock, pumps, valves and and were blasted, cleaned, had welds chemical inject skid repaired, and recoated in drydock. were fully refurbished and a new fscally-

Mooring system rated offoad metering When the vessel was frst installed, system introduced. the mooring system was rated to the

All at-risk areas, latest 1989 standards. The rating has including the forward now been increased to 2010 standards, blast wall, that pro- increasing the minimum break load tected a temporary ref- (MBL) of the chain to 858-tonne—a uge area, were brought 17% improvement on the old R4 chain. up to a 90-minute jet To meet new codes, including DNV- fre (J90), standard, OS-E301, the damaged 10-point moor- when previously only ing system was replaced, upgraded, the risers and the with new mooring chain forged by emergency shutdown Spain’s Vicinay Cadenas. Fair leads valve were covered. were also increased to an MBL of

All vessels were reclad 858-tonne. in Foamglas and a The Vryhof Stevpris anchors were

Terostat outer cover. overhauled and new Smit towing

Insulation around brackets and chocks ftted fore and aft, pipelines was also for vessel positioning during hook-up. upgraded to hard foam,

The 134 cylinder bearings (67 sets of two) on the 4000-tonne, 20m-diameter, hydraulically oper-

More than 550-tonne of ated turret amidships, were over- steel was was replaced hauled, and the carousel steelwork on the , Gryphon Alpha and drag chain overhauled. The tur- while it was in drydock.

ret turning and locking system was

Photo: Maersk Oil North Sea UK

OE | September 2013 118 000_OE1013_geofocus1-gryphon.indd 118 8/19/13 12:14 AM

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