Construction company recognised for ‘innovative’ Waitangi Rail Bridge reconstruction

Piles driven 34 metres into the ground with an 11-tonne weight will ensure the load-bearing capacity and flood resilience of the new rail bridge rebuilt near Napier after Cyclone Gabrielle.

Whangārei-based company United Civil received a highly commended award at the Civil Contractors NZ (CCNZ) Hirepool Construction Excellence Awards for the innovative methods they used during the construction of Bridge 217 in Napier.

The original six-span 75m Waitangi rail bridge, ran over the Tūtaekurī River parallel to State Highway 51 near Waitangi Regional Park before it was washed away during Cyclone Gabrielle.

The bridge reopened on September 15 last year, 17 weeks after reconstruction work began and seven months after Cyclone Gabrielle.

CCNZ judges praised United Civil’s use of innovative construction methods to deliver a high-quality project in challenging conditions and the 17-week timeframe.

United Civil managing director Andrew Campbell said piles had to be driven around 34m into the ground before the surrounding soil could support the bridge, the freight trains running over it and the force of the river when it was in full flood.

The piles were 760mm diameter steel tubes which were bottom-driven into the earth with a 100-tonne crawler crane using an 11-tonne drop hammer.

“Usually we would build a temporary structure (staging) on temporary piles, to allow us to advance the pile driving crane. In this case, we went straight into piling the new (permanent) bridge piles and used these piles to support the temporary staging,” Campbell said.

MC Sacha McNeil, left, CCNZ vice president Jeremy Dixon, United Civil senior project manager Jacob Dunn and Hirepool general manager of sales and marketing Gary Richardson. Photo / CCNZ Facebook

“This allowed us to expedite the construction process and reduce the risk associated with the additional piling that would have been needed if we had built a separate temporary structure.”

He said their team worked closely with KiwiRail to optimise the design and find ways to simplify construction and speed up the construction of the replacement bridge.

“This bridge was so important to the economic recovery of the region following the cyclone and it was completed safely, at pace, to a high standard, and in a collaborative manner that is a credit to all involved,” Campbell said.

The project was recognised in Category 3, for projects with a value of between $5 million and $20 million.

The section of the Palmerston North to Gisborne line between Napier and Gisborne has been closed since 2012 due to a washout.

The section between Napier and Wairoa reopened in 2019 for logging, but hopes for the section between Wairoa and Gisborne to reopen were dashed by a slip in 2021.

Damage from Cyclone Gabrielle meant the section of rail line between Napier and Wairoa was closed again last year, and Kiwirail is due to present “detailed costings and options” for reopening the rail line to the Government for it to consider.