Ruapehu Road rail overbridge replacement

The existing bridge, with components over a century old, was rapidly deteriorating and posed a safety risk; it had become a bottleneck for both local and regional traffic. The aim was to provide a safe and efficient replacement that would not only alleviate the strain on the existing infrastructure but enhance community connectivity and the well-being of the region.

The Ruapehu Road rail overbridge replacement became a pivotal project aimed at replacing an ageing piece of infrastructure that spanned the railway corridor in Ohakune.
The existing structure was limited to handling three and a half tonne loads from its full capacity over a 10-year period, significantly impeding the flow of essential goods and services to the region. The challenge was not only to replace the bridge but also to future proof the needs of the community by ensuring that the new infrastructure would facilitate smooth transportation for heavy loads, allowing access to crucial facilities such as the water treatment plant, carrot processing and the ski fields. Addressing the limitations of the old bridge would enhance the access of the community to recreational activities and drive traffic to the town centre.

GHD worked closely with Ruapehu District Council to devise a robust business case and secure funding for the project, and with KiwiRail throughout the project life to ensure smooth construction across the railway corridor. The rail overbridge required a tailored design and used curved steel beams to accommodate the unique alignment of the bridge, in that one side needed to be lower to accommodate the KiwiRail power supply, while maintaining its structural integrity.

The replacement of the bridge has accommodated for heavier loads and more efficient access to water, agriculture, and recreational facilities and for smoother transportation for events in the region like Mardi Gras, the Carrot Festival and the ski season by enabling a shorter route for travellers. This new asset to the community has opened up new possibilities for local recreational activities and tourism opportunities.

Close engagement with the community and local iwi, Ngati Rangi, were crucial to the smooth progression of the project. Engaging with iwi early on in the project’s life allowed us to better understand the land and waterways surrounding the project and ensuring all cultural and environmental considerations were prioritised. 

Hari Smith, GHD Civil Engineering Technician, said “We were able to engage with them with enough clarity and enough foresight at the right times.” 

Ngāti Rangi led the opening ceremony of the bridge with a karakia and welcomed guests including the Ruapehu District Council CEO, Mayor, councillors, and members of the community onto the bridge. 

While the project marked a significant milestone, there are ongoing plans to further improve the approaches to the bridge in the upcoming construction season, ensuring seamless integration and enhancing overall accessibility.

The overbridge replacement resulted in safer and more efficient infrastructure for the Ruapehu community, allowing for smoother transportation of goods and services, improved access to essential facilities, and better access for tourism and local businesses.
This bridge now provides the Ohakune community better and safer access to the town centre, ski fields and beyond!