Salvors nearly ready to lift Rena 'house' block

The Rena's wreck on the Astrolabe Reef. Photo/File

Rena salvage operators are preparing for a major milestone in their task of removing the wreck from Astrolabe reef off the Bay of Plenty.

Resolve Salvage & Fire's specialist divers are in the last few days of preparation before they begin to cut and lift the 700-tonne accommodation block from the sunken stern section of the grounded ship.

This stage of the operation marks months of planning and preparation, and will require two separate near-perfect 72-hour weather windows.

There have been more than 200 days this year when salvors were unable to operate on the wreck due to weather and oceanic conditions.

More than 75 days of diving at significant depths have been needed to prepare the "house" structure to be cut and lifted. Divers have just three more days of work to feed the last two of eight lifting chains through before the cutting mechanism can be set up.

Preparations have resulted in two incidents, while diving at depths of up to 46 metres. Both divers received treatment by an Auckland-based hyperbaric specialist doctor before being treated overnight in Tauranga Hospital but sustained no serious injury.

The cut and lift operation will see the deployment of the RMG 280 and the RMG 500 crane barge out to the reef. A specialised chain cutting method will be used due to the stern section's 55 degree list, in order to cut the house into two sections of about 350-tonnes each.

They will be loaded on to a third barge, the RMG 1000, cut into smaller pieces and taken back to the Port of Tauranga for recycling.

The decision to remove the house was made in response to community consultation and concerns.