The scale of work to remove flood-damaged Te Reinga Bridge near Wairoa this week is unlike anything else Wairoa-based Quality Roading and Services and other contractors have worked on.
The 300-tonne Te Reinga Bridge was collapsed into the river on Monday and has been winched up out of the water.
“The specialist operators overseeing this part of the programme believe it could be the heaviest pull that has ever been done in New Zealand,” QRS construction manager Mike Wilson said.
Te Reinga Bridge was damaged in heavy rain during March 2022 and was closed to heavy traffic. In February of this year the bridge was severely compromised during Cyclone Gabrielle when its middle pier washed away.
With no bridge, Ruakituri residents have had to travel two hours to Wairoa — a trip that would normally take half an hour.
QRS has managed the project to remove the flood-damaged bridge before a temporary Bailey bridge is installed.
Dozens of professionals have been involved in the removal operation this week, including specialist dive teams, demolition experts, towing and crane operators, welders and piling and bridging contractors.
Wairoa District Council has directed the project with guidance from WSP engineers.
“It’s the most complex project many of us have ever been involved in,” Mr Wilson said.
“The pulling was made complex by the sheer weight of the structure, as well as continuously changing load paths, difficult ground conditions and damaged bridge components.”
Mr Wilson said the need to look after people’s safety and the whenua was paramount.
“All of us have worked together well and have taken a shared, careful, measured approach. We’ve created practical, workable solutions for every new situation.”
The bridge is estimated to weigh 300 tonnes — equivalent to a Boeing 747 aircraft.
Contractors had already removed parts of its concrete deck to make the bridge lighter.
Then crews demolished one of its last two remaining piers.
“Remarkably the bridge stayed in place on one pier, with each end still nestled into the bank,” Mr Wilson said.
“It’s testament to the skill of designers and contractors from the 1970s that the bridge required so much force — from cyclones and eventually a hydraulic excavator — to get it down.”
Te Reinga Bridge was successfully collapsed into the riverbed just before lunch on Monday.
“It was an incredible moment,” Mr Wilson said.
By Thursday afternoon, operators in seven tow trucks had successfully winched the bridge up out of the water.
Mr Wilson likened the towing and winching operation to that of an orchestra.
“The heavy machinery operators worked together to make sure the pulling was even and precise. It’s a credit to the professionals involved.”
Gisborne Hiabs were among the crews involved.
“Around 60 people, eight excavators, seven tow trucks, and four bulldozers were on site every day this week,” Mr Wilson said.
“The bridge has been cut into pieces, removed and will be recycled.
“Staging platforms on either side of the river are being built so that a 42-metre Bailey bridge can eventually be constructed across the gap.”
Contractors working onsite recently included Lattey Group, Ward Demolition, Bay Underwater Services, Gisborne Hiabs, Rowe Motors, Ace Heavy Haulage and IBA Engineering.