Testing is continuing on a crane barge that will be used to remove more than 1200 containers precariously perched on grounded ship Rena.
Salvors yesterday moored the barge Sea Tow 60 at the stern of the leaning container ship, which has been grounded on the Astrolabe Reef off the Tauranga coast since last month.
A second crane barge is also making its way from Singapore to the Bay of Plenty as the operation shifts focus to the removal of containers, after the weeks-long oil extraction operation wrapped up on Sunday.
The final remnants of oil will continue to be removed where possible, said Maritime New Zealand.
Testing of the ST60's cranes started yesterday and could take one or two days before container removal could begin, said Maritime New Zealand salvage unit manager Arthur Jobard.
"The salvors are taking this time to make sure that all the equipment and systems are ready and working properly before commencing operations.
"They also need good, calm weather to operate effectively, with safety being the top priority,'' he said.
When testing was complete, salvors would be lowered down in a cage to get the containers ready for removal.
But Mr Jobard warned the speed at which the salvage teams could work depended on many different factors.
"This includes weather and how complex it proves to be to access the containers, many of which are badly damaged and in very precarious positions.''
The operation's complexity was compounded by the need to design a container decoupling system, given the difficult lean of the ship and the position of the containers.
"Each set of containers will present its own unique challenges.
"This means it is impossible to predict exactly how long it will take to safely remove all of the containers on board - but realistically, it is likely to take several months of patient and careful work.''
A second barge, Smit Borneo, was making good speed and was expected to arrive in Tauranga by early December.
It was a bigger barge and its cranes have greater reach, so salvors hoped it would speed up container removal operations, said Mr Jobard.
There have been no new reports of fresh oil ashore, said Maritime New Zealand.
An announcement will be made today about lifting existing beach access restrictions in the area.