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Moving a brittle, 102-year-old building from the edge of a collapsed mine shaft presented more than a few challenges for engineers.
So it was with a huge sense of accomplishment that the team involved in shifting Waihi's historic Cornish Pumphouse watched its 301m, three-month journey come to an end.
"The whole aim was to move the pumphouse in one piece and that has been successful so we're very, very pleased," Newmont Waihi Gold general manager Adriaan van Kersen said.
The mining company, which operates the Coromandel town's Martha Mine, is required to preserve the pumphouse - a heritage building - under its resource consent for mining.
The pumphouse was built to remove water from underground mine shafts, and did so at the rate of 7000 litres a minute until it was decommissioned in 1913.
The decision to move the 2000 tonne, 20m high building was made when the tilt it developed after an adjacent mine shaft collapsed in 1961 started worsening.
Engineers from Wellington firm Dunning Thornton Consultants, which moved the Museum Hotel in 1993 to make way for Te Papa, came up with a unique plan for the move.
Using concrete beams, jacks and teflon pads, they delicately slid the structure 26m to the south, then 270m to the west.
The ground along the way was recontoured and strengthened to take the building's weight.
The digging uncovered more than 5000 relics, including old mining buckets, bottles and tin match boxes from the 19th century.
Workers cast five concrete beams in tunnels cut in the structure's base, and the pumphouse was moved south on these beams, away from the collapsed shaft.
For the second part of the journey west, it travelled on pairs of beams 18m long, laid to form a parallel track.
As the pumphouse cleared one pair of beams, those beams were rejoined to the other end of the track.
Each pair of beams was moved five times throughout the 270m stretch - a "recycling" system that Dunning Thornton director Adam Thornton said was developed for the project.
Also unique were the teflon pads placed on the beams to slide the structure.
Mr Thornton said such pads were sometimes used when sliding new sections of a bridge into place, but they had not been used in this way before.
"It's a first as far as we're concerned," he said.
Flat jacks were another innovation, placed under the pumphouse and on top of the teflon pads to ensure weight was evenly spread at all times.
"It was like a floating mattress," Mr Thornton said.
Compared to the Museum Hotel, which was a modern building better able to withstand movement, the brittle pumphouse was extremely vulnerable to cracks.
But the move had progressed with few hitches, apart from taking a little longer than expected, Mr Thornton said.
The journey ended when Building Solutions contractors moved the pumphouse into its final position overlooking Seddon St.
The project attracted interest from local residents and visitors, including a man who flew from Europe to watch the last days of the move after reading about it on the internet.
The cost of the project was $4.2 million, but the mining company's Mr van Kersen said it was worth every cent.
"We've given the pumphouse the opportunity it deserves to be preserved," he said.
The site, still officially a work site, will open to the public for the day on December 16.
Landscaping and planting will be done before the pumphouse is opened as a tourist attraction in February.
