Two new Rowan drillships are being kitted out with digital acoustic positioning systems delivered by Nautronix.

The drillships, Rowan Relentless and Rowan Reliance, are being fitted with emergency BOP acoustic control systems under a US $10 million contract won by Nautronix.

Under the deal, which is for a total of four rig systems, the contractor will be supplying its NASDrill RS925 and NASeBOP systems. Nautronix says the NASDrill RS925 system, which uses short and long baseline acoustic positioning technology to provide input to dynamic positioning systems, will provide accuracy of 0.15% of slant range in SBL mode, and accuracy of up to 1 metre in LBL mode, independent of water depth.

The benefit of the NASeBOP control system, which also uses acoustic digital signalling technology, is that it offers backup control of BOP functions if primary communication and control systems fail, by providing reliable communication between the surface vessel and subsea device, according to Nautronix.

The company added that the systems are among the first of their kind to meet an ABS Integrated Software Quality Management standard, while the NASeBOP system also meets an ABS Classification of Drilling Systems (CDS) standard, which required the equipment to undergo environmental testing, including shock and vibration tests to ensure its reliability.

Offshore