A portfolio of recent rail bridge replacements

Helping KiwiRail improve rail network resilience and reduce maintenance by replacing decaying timber piers and piles on bridge structures.

Beca has been working alongside KiwiRail to assess options, design, and monitor the construction of bridge replacements in the Bay of Plenty region (Bridge 91 on the East Coast Main Trunk), in the Waikato region (Bridge 229 on the North Island Main Trunk), and in the Wairarapa region (Bridge 63 on the Wairarapa Line). 

We addressed common site constraints such as extensive flood issues and narrow clearances for bridge decks. Online bridge replacement solutions were KiwiRail’s preferred solution to eliminate the need for significant adjustments to the rail alignment. 

The Beca design and construction methodology for replacing the bridges was developed to enable a changeover of existing to new structures in a limited railway line closure period. The team achieved this by carrying out most of the bridge replacement works before the temporary rail track closure, including the substructure with all piling.  

The combined in-situ and precast concrete construction proved advantageous for the online replacement of small span rail bridges. It offered long-term durability, low maintenance, and off-site construction work. 

Our collaboration with KiwiRail and contractors on these various bridge replacements, despite facing common site constraints, resulted in the successful implementation of efficient bridge replacements.