The sensors have all been set with an alert threshold. If triggered by slope or debris movement, a notification is sent to KiwiRail field engineers, train controllers, and WSP. A photograph of each site is taken every 15 minutes. If its sensor threshold is triggered, usually due to slope movement from a heavy weather event, a site photograph is taken every minute.
WSP principal instrumentation engineer Mike Lusby says the monitoring system has been designed to reduce the risk of trains and passengers from being adversely impacted by landslips and ground movement.
“While the system can’t stop slips from happening, it does give KiwiRail warning in real-time, so trains won’t plough into fresh slips, derail and put people’s safety at risk.
“When a weather bomb hits, if the sensors show things are changing, the system will immediately contact KiwiRail’s field engineers and train control, saying ‘there’s been an event, you need to check this out’. They can then look at the camera footage to verify and respond.”
KiwiRail performance manager Shaun Bullard says real-time monitoring of slip-prone sections of rail line is crucial, as slips and ground movement can result in significant damage to the infrastructure, leading to safety issues, service disruptions, delays, and expensive repairs.
“By constantly monitoring the ground conditions of the line, we can detect any changes promptly and take corrective measures before severe damage occurs.
“The system also helps us maintain safe, efficient, and reliable railway services. And as extreme weather conditions, triggered by climate change, become more frequent, this kind of real-time monitoring lets us respond quickly and proactively to minimise the impact of these events on our rail infrastructure.”
The same WSP system is soon to be installed on a section of Wellington’s Johnsonville rail line.