Oil rig weather

A spell of very favourable weather is required before the stricken Transocean Winner oil rig can be loaded onto a heavy lift ship.

Dave Walls of owners' Transocean attended a public meeting in Stornoway about the damaged platform's removal.

The audience heard of a plan to transfer the listing rig onto the Hawk, one of the biggest heavy lift carrier vessels in the world for its eventual final voyage to a scrap yard in Turkey.

For the crucial 12 hour loading period, a maximum 15 knots wind, 33 centimetre swell and an one knot current is essential, highlighted Mr Walls.

Good weather vital for oil rig removal

14 September 2016

He stressed they would “not take any chances” so everything will wait “for the right weather window.”

He added: “We don’t want any oil spill, no matter how small. Every step will be risked assessed.”

Hugh Shaw, the UK government‘s salvage advisor accepted finding a weather window would be difficult at what “isn‘t the best time of year.”

“We will simply maintain the status quo as long as we have to.”

He said the “worst case scenario” would be getting to the end of year and the rig is still in Lewis.

The rig is sitting 12.5 metres deep in the water but this must be reduced to a 8.6 metre draft or the transfer onto the ship will not proceed.

A propeller thruster unit extending three metres below the rig’s base will be cut off on Wednesday. A similar unit was removed yesterday.

The 65,000 tonne Hawk will first discharge a jack-up rig at Invergordon later this week and is expected at Lewis around 20 September.

By late September, the Transocean Winner will be floated onto the semi-submersible vessel, if autumn gales hold at bay.

Then the rig is expected to be towed into deeper water a mile or two miles north of its present position at Broad Bay.

The rig will then be gently floated onboard and the ship will rise out of the water.

It is proposed for the heavy-lift ship to take the rig towards Stornoway where it will lay-up at an anchorage at the back of Arnish lighthouse, outside just outside harbour limits.

There the 17,600 tonne platform will be welded to the deck of the ship - a process which is set to take up a few days and also requires a period of dry weather - to secure it for the voyage to the Mediterranean in early October.