Oil Rig off Perth coast on the move

THE oil rig that has dominated the horizon off City Beach all summer is on the move.

The almost 40,000-tonne Ocean Monarch drilling rig owned by Texas-based Diamond Offshore has been parked off the Perth coast for about three months undergoing maintenance work.

Two SolstadFarstad anchor handling tug supply vessels have taken three days to recover the eight 15-tonne anchors that have been holding the 105m wide deep-water platform in place.

The vessels, the Far Statesman and Far Senator, each with 15 crew aboard, will now take up to 25 days to tow the semi-submersible drilling rig to Bass Strait, where it will be chartered to Cooper Energy.

Far Statesman captain Paul O’Connor said the journey would be at walking pace.

“We expect to tow this rig at about three knots, which is about 5.5km/h,” he said.

“It’s going to be a two-vessel tow, the Far Senator, which is our sister ship, with the primary tow, and we’ll be the secondary tow.

“If something goes on, you’ve got a secondary vessel, especially going into the Great Australian Bight, where it’s so isolated.”

The vessels will have about 1.2km of tow wire between them and the rig as they travel.

But it may not all be smooth sailing along the way.

“One of our sister vessels has just gone across and they were recording 11m swells going through,” Capt. O’Connor said. “That’s three or four storeys high.”

Each vessel is capable of pulling about 250 tonnes static load and can work with anchors in depths of up to 3000m.

The SolstadFarstad vessels will undertake rig support duties when the Ocean Monarch is delivered to Bass Strait.