Critical Mainline Station Fault Finding with CableGuardian
December 7, 2023
CableGuardian demonstrated its effectiveness in preventing significant train disruption on the UK rail network. By enabling staff to quickly identify failing cables before faults occurred, Network Rail avoided a signalling power failure and potentially thousands of minutes of train delays.
The Challenge: Complex Rail Network Requires Proactive Cable Monitoring
A critical mainline station in West England is served by multiple feeders and spans approximately 48 km of cables, switchgear, and related infrastructure. Traditional fault-finding methods are time-consuming and disruptive, often requiring physical testing across long stretches of network before locating faults.
Network Rail needed a solution to monitor insulation resistance (IR) in real time, detect potential failures early, and support proactive maintenance—avoiding costly service disruptions.
The Viper Solution: Tiered Monitoring and Roaming CableGuardian Units
Twelve CableGuardian units were installed permanently in a Tier 2 configuration across existing equipment buildings. This setup continuously monitors the network and trends insulation resistance across feeders, enabling early detection of anomalies.
To complement the permanent system, Network Rail acquired two portable CableGuardian sets with split-core measurement coils. These units allow maintenance teams to rapidly deploy a temporary Tier 1 system, capturing more localized data in areas highlighted by Tier 2 trends. The units are fully supported by Viper Innovations’ Technical Support Team.
A portable CableGuardian unit was deployed along a feeder identified by Tier 2 data as having low IR. The unit immediately detected a cable section with 0.55 MΩ, significantly below expected values. Manual testing confirmed the fault, and isolating the section increased feeder IR to >10 MΩ, preventing a potential power failure.
The portable unit was then redeployed to another feeder flagged by Tier 2 monitoring. Here, a section with <400 kΩ IR was identified, and the unit continued to monitor the cable over several weeks to trend its response to environmental conditions, enabling informed maintenance planning.
Results & Benefits: Fast, Non-Invasive, and Cost-Effective
- 48 km of cables monitored continuously
- Fault identified and confirmed in hours rather than days
- Planned maintenance potentially reduced by up to 80%
- Avoided thousands of minutes of potential train delays
- Non-invasive installation: portable units deploy without disruption
- Early detection supports proactive maintenance, reducing catastrophic failures
CableGuardian provides unmatched visibility of cable health, trending insulation resistance from 1 kΩ up to 10 MΩ, allowing Network Rail to pinpoint risks and intervene long before service is affected.
The Lead Engineer involved in this process stated:
The information provided by CableGuardian, made available by the remote Technical Support of Viper Innovations and the subsequent actions of our Engineers, enabled us to evaluate the performance of specific cables and identify the issues stated within a single morning and without disrupting train services.
Intelligence installed in Action
By combining Tier 2 permanent monitoring with portable Tier 1 deployment, Network Rail transformed what would have been a lengthy, disruptive fault-finding process into a fast, targeted, and non-invasive solution. This case study highlights why CableGuardian is a must-have tool for rail maintainers, enabling early intervention and reducing the risk of service-impacting failures across signalling power networks.