Rail engineers face the growing challenge of managing the impact of a warmer, wetter climate on infrastructure. Flood events are becoming more frequent, causing significant damage, delay, and disruption. Surface water can damage track as well as signalling, power, and comms infrastructure. It can wash away foundations and remove material from cuttings, leading to collapse and failure. Increasing soil moisture reduces the stability of slopes, causing landslides and debris flows.
Ground drainage is the primary tool used to manage surface and subsurface water movement. While Network Rail has committed to invest in upgrading track drainage, this is a slow and expensive process, so the focus must remain on managing existing assets to optimise their performance and to detect problems before they become critical.
Challenge
Data relating to water level, flow, and silting have traditionally been gained by visual or in-pipe surveys conducted on a periodic basis, providing data that are valid only at a single point in time. Because site conditions can change in a short (sub-hour) time frame, there is a need for more frequent or continuous data updates, with automation of systems to trigger alerts if thresholds are breached. Provision of such systems is challenging because sites are typically remote and without mains power, most drainage infrastructure is hidden below ground and any instruments placed inside catchpits, pipes, or culverts must be extremely rugged and durable.
A new approach to monitoring
Working with Network Rail, engineers at Senceive have developed a modular automated wireless alerting system to provide near real-time data for multiple years with minimal maintenance. Using wireless remote monitoring technology these systems can be integrated with slope movement monitoring instruments. Multi-sensor wireless systems in remote locations provide near real-time, continuous data to support earthworks risk management.
Such a system may include radar- or laser- based water level sensors, weather stations, soil moisture meters and piezometers, and automated cameras. The cameras are smart IoT devices that automatically send images of the site when requested or when triggered by out-of-threshold readings from other sensors. Equipment is battery or solar powered and data transmission uses the cellular network, so no fixed electricity supply or communications infrastructure is needed.
Senceive’s smart wireless solutions are helping engineers to manage growing flood risk.
Case study: drainage monitoring in south London
A track drainage system in South London had been prone to blockage and flooding, presenting risks to a nearby substation. A programme of drainage cleaning and remediation was carried out and Network Rail commissioned monitoring to determine its effectiveness:
- Laser Water Level Monitor inside the manhole chamber to monitor water levels.
- Solar-Powered 4G Camera: Positioned above the manhole for near real-time visual verification of overflow events, day and night.
- 4G Cellular Gateway: To securely transmit data to the WebMonitor cloud-based portal – providing instant access to continuous water level readings and camera images.
The battery-powered, long-life, water level sensor was installed quickly in an inspection chamber, eliminating the need for complex wiring and reducing the need for further opening of the chamber and therefore supported safer working practices. Predefined trigger levels ensured immediate notifications via SMS and email if water levels exceeded safe thresholds. 
This enabled Network Rail to proactively manage drainage risks, providing near real-time alerts and live visual data for informed decision-making. The six-month dataset validated the effectiveness of the drain cleaning and remediation works, ensuring continued protection of a nearby substation.
Image credit: Senceive