A temporary fix to a damaged rail bridge over the Rangitata River in Canterbury is on track to be operational by the end of the week.
One of 34 piers on the bridge was washed away by flood waters on April 12 and is yet to be found.
Contractors have been working ever since to get the bridge open again.
"Our staff and contractors have been working hard on temporary repairs to the rail bridge over the Rangitata River and solid progress is being made," KiwiRail chief infrastructure officer André Lovatt said on Monday.
"The pigsty structure, which is making sure the two spans don't sag any further or collapse into the river, was in place on Friday night. This was an important milestone to ensure safety."
Lovatt added that over the weekend workers began using a 250-tonne crane to push four steel caissons deep into the riverbed to form the supports of the temporary pier.
"With this work now complete our next step over the coming days is to lift the sagging spans and slide in a large cross bar (cross head) that will rest on the caissons and keep the bridge up. This will then be welded into place," he said.
The final step will be to replace damaged rail on the bridge.
"There is still a lot to do and, provided conditions stay favourable, we're still aiming to have the line reopened to freight trains by the end of this week," Lovatt said.
"KiwiRail continues to work with our customers to keep their freight moving while the bridge is being repaired."
Work to permanently replace the pier will be done once the line is open.
