Protecting KiwiRail passengers on New Zealand's slopes

The WSP Research Hub in Petone, Wellington, houses a veteran instrumentation and monitoring team with experience assisting asset owners and infrastructure managers. The team sets up data collection processes and then analyzes the material to produce safety and resilience insights, helping clients better understand and manage the risks that their assets face.

KiwiRail chose to work with us after a prior collaboration to create a rail corridor scanner. The success of that project—a LiDAR-based tool attached to Hi-Rail inspection vehicles to help inspectors detect obstructions on the track—led KiwiRail to reach out to WSP about a monitoring solution for the Kāpiti line.

KiwiRail also recognized that while there were sensor solutions available on the market, none of them were properly suited for the project’s specific needs. By working with us, the client was able to co-create a tailored solution that took the area’s unique circumstances into account.

“It’s a strong example of the innovation that clients and suppliers can achieve when they collaborate to develop a solution that is genuinely fit for purpose,” explains Urvaksh. “While similar tools exist in the market, this system stands out for its sophisticated combination of sensors and its seamless integration with the train control network. This integration enables real‑time alerts to be directed immediately to the right response teams, significantly enhancing the effectiveness and timeliness of operational decision‑making.” 

For the Kāpiti line, the team helped KiwiRail set up a combination of slope movement and debris sensors, rain gauges, soil moisture metres and night vision cameras. These instruments monitor the rail line for obstructions on the tracks, which can come in the form of “over-slips,” debris that falls from above onto the tracks and under-slips, which occur below the track. In addition to being real-time, this equipment is sustainable and standalone. No existing infrastructure was required to set up or maintain the network, with all the devices relying on solar power.

With 24/7 coverage, the sensors alert KiwiRail field engineers, train controllers and WSP when slope or debris movements exceed normal parameters. Along with these alerts, we’ve installed real-time live view cameras with 7-day playback and a 6-week time-lapse at each site. Now KiwiRail engineers have a visual overview of the circumstances around an event and can view current site conditions via live coverage, helping them persevere through high-tension weather incidents.

“While the system can’t prevent slips from occurring, it provides KiwiRail with real-time alerts across some of the most remote and expansive stretches of its network—places where no one might be nearby to witness a slip firsthand,” says Mike Lusby, WSP Technical Principal of Instrumentation. “When a weather bomb hits and sensors detect ground movement, the system instantly notifies KiwiRail’s field engineers and train control, pinpointing the exact location. They can then pull up camera footage tied to that specific spot, verify the situation in real-time and dispatch teams with precise geographic coordinates. This ensures a rapid, targeted response before trains encounter the hazard.”

The sensor system also allows KiwiRail to take a more proactive approach to weather events. The real-time monitoring, precise to a 0.075 -degree angle, provides the data to build long-term averages of slope movement. By combining weather data and seasonal forecasts, the teams can predict periods of greater risk and plan accordingly.

The new system has been a major success, guarding 60,000 daily passengers. The project was also recognized with the prestigious ACENZ Silver Innovation award.

“I would say the project is definitely beneficial for us,” Said Urvaksh. “It has made the network safer, and safety is our highest priority. This line is especially critical, so we need it to be quite resilient.”

The technology deployed on the Kāpiti line has numerous other use cases across New Zealand and around the world. WSP is currently working to help install the system on a section of Wellington’s Johnsonville rail line, which KiwiRail also manages. 

Additionally, in October 2025, the client reached out to our Kāpiti project team in response to an emergency at a national park near the rural community of Ongarue. Major rainfall and flooding resulted in geotechnical instability and landslides in the historically unstable area, which is near the site of an infamous 1923 railway disaster where a train collided with a boulder dislodged by a landslide. KiwiRail reached out to the team after hours on a weekend, but even with that short notice, we installed instrumentation across the affected area within a week.

The client is also working to make the solution available throughout the organisation, allowing personnel to request access for their own projects, with plans to integrate the monitoring technology into their new train control solution. In addition to that work, KiwiRail recently awarded us a project to combine all monitoring across their national network into a single WSP dashboard.

And the benefits go beyond the tracks. The team also successfully deployed it for other clients, notably to help the New Zealand Transit Authority repair and maintain the road in the Mangamuka Gorge. In 2022, the 14-kilometre road was heavily damaged by ground movements. The team leveraged lessons and practices developed during their work with Kiwi Rail to help fix the road and guard against future incidents.

The solution has strong potential uses throughout New Zealand, which is particularly vulnerable to landslides due to the country’s geography. But the technology shows promise outside of New Zealand too, especially as our world faces worsening weather conditions due to climate change. 

Jazz Pabla, Chief Innovation Officer and Regional Digital Lead for WSP Canada, recognises the unique importance of this project, “When I heard about KiwiRail, I was super proud that WSP had developed this and then immediately thought, ‘OK, we need to bring this type of technology to our clients and communities in Canada as well.’ I felt just a bit of a wow factor that we had this and that it was something real and had actually saved lives in New Zealand. 

Right now, we're setting up the same instrumentation for a community in British Columbia, in a key area where landslides have occurred. We're quite excited to follow in the Kāpiti Line’s footsteps, it's a strong product and it's great that WSP can show that a true innovation mindset really does exist and more importantly, it exists in the form of a tool that saves lives.”