Moving beyond blanket renewals: embracing condition-based spot solutions for railway signal power systems
April 14, 2025
Blanket renewals, which involve replacing entire systems based on age or estimated lifespan rather than specific non-functioning components, are the usual approach for maintaining safe railway operations. However, blanket renewals fall short in terms of value for money and sustainability, and for minimising service disruption, all of which are critical to meeting Network Rail’s CP7 KPIs. Condition-based spot replacements offer a new solution. Identifying which trackside parts, such as cables or transformers, need to be switched reduces costs and limits operational disruption while maintaining safety and maximising efficiency.
This article explores the downsides of traditional renewal methods, and the opportunities presented by spot renewals within the rail sector.
The downsides of traditional renewal methods
In addition to the challenges already highlighted, traditional renewals are often:
- An inefficient use of human resources – a larger project team is required to replace entire systems
- Logistically complex – executing wholesale signalling power renewals leads to complex logistical challenges, such as widescale track closures and the need to commission specialised machinery
- A missed opportunity for rail asset managers to gather – and benefit from – real-time, data-driven insights
By contrast, spot renewals are resource and cost-efficient and improve safety and efficiency. A system like Viper Innovations’ CableGuardian facilitates spot renewal.
Spot renewals with CableGuardian
CableGuardian enables targeted replacement through advanced diagnostics that proactively monitor degradation over time. It provides early warning of graceful decline as well as detects sudden faults in live signalling power systems. It integrates insulation resistance (core-to-earth) measurement and spread spectrum time domain reflectometry (SSTDR) (core-to-core fault detection).
By pinpointing specific assets that require attention, CableGuardian ensures minimal intervention using a tiered approach – Tier 2 for feeder level insights and Tier 1 for more detailed insights into individual cables and trackside equipment housings or groups of equipment along a feeder. This allows rail engineers to target critical components effectively, improving safety, value for money, sustainability and reducing service disruption.
Rail asset managers can be more proactive around maintenance while leveraging real-time data to improve cost efficiency and reliability.
CableGuardian in the field: cost savings on the Western Route
The Western Route faced repeated issues around the Yatton area. Rail asset managers initially considered a full cable replacement. However, CableGuardian’s precise assessment showed the faults were isolated to specific sections of the system. This meant that repairs need only focus on affected parts, avoiding the cost and disruption of a complete renewal. CableGuardian’s continuous monitoring predicted and prevented issues early, saving costs over the system’s lifecycle. The temporary deployment option allowed for informed decisions without a full upfront investment, supporting budget-friendly decision making.
The successful implementation at Yatton demonstrated how targeted renewals, backed by accurate diagnostics, can replace costly blanket renewals.
How to implement condition-based spot replacement with CableGuardian
Implementing condition-based spot replacement with CableGuardian is simple and can often be planned during less disruptive times, minimising operational impact. The implementation process is as follows:
- Install CableGuardian
Deploy and non-intrusively connect the system without needing to shut down the 650V power supply, ensuring minimal disruption. - Monitor in real time
CableGuardian offers continuous, real-time monitoring with advanced diagnostics that use insulation resistance measurement and SSTDR to locate faults in signalling power systems. - Target repairs
Use insights from CableGuardian to plan and execute targeted interventions at different levels, including Tier 1 and Tier 2 condition-based assessments.
Budget limitations and caution may mean that rail asset managers want to deploy new systems temporarily for condition-based maintenance before committing to a full-scale deployment. Viper Innovations offers a consultation option to address this concern, helping rail asset managers assess the feasibility and potential benefits of CableGuardian in a real-world setting.
Unlike some alternative systems, CableGuardian provides reliable fault detection and accurate diagnostics, offering clear, actionable insights. There is nothing worse than spending valuable time using a system that provides insufficient, unclear or incorrect data, which leads to repeated and unnecessary work, especially in challenging environments like trackside areas. With its wide range of measurements and reliable insights, CableGuardian ensures system condition assessments are made efficiently and are right first time, enabling areas that require spot renewals to be identified effectively. This prevents missed opportunities.
The key benefits of CableGuardian
CableGuardian provides a data-driven approach to capital works on signalling power systems that focuses on safety, efficiency and sustainability. Its continuous monitoring of key parameters, like insulation resistance and voltage drop, help teams find and fix issues while keeping services running. Temporary deployment options allow rail asset managers to use Tier 1 and Tier 2 condition-based assessments to evaluate system performance before committing to a permanently installed CableGuardian system, if they wish.
The benefits of adopting CableGuardian are clear: less disruption, optimised resources and increased reliability. By basing decisions on condition assessments, CableGuardian moves asset managers away from costly blanket renewals to more strategic, budget-friendly solutions.
This new approach to renewals is resource-efficient, enabling teams to do more with less.
