Cambridge Commissioning Support (C3R & CSIE) — Christmas 2025 Blockade
Client
ALSTOM / Network Rail (via supply chain partners)
Programme
Cambridge Re-signalling & Control (C3R) and Cambridge South Infrastructure Enhancements (CSIE)
Delivery Period
Year-round commissioning support culminating in a 12-day blockade over Christmas 2025
Project Overview
Deploy provided year-round commissioning support for the Cambridge commissioning programme, supporting the successful delivery and commissioning of Stage 2 of the C3R and CSIE projects during the Christmas 2025 blockade.
Stage 2 represented a major milestone for the programme, delivered through close collaboration between ALSTOM, Network Rail and the wider supply chain. The works formed part of what is recognised as the largest and most complex MCS Infinity installation in the UK, replacing legacy signalling and control infrastructure and enabling future capacity improvements across the Cambridge area.

The Challenge
The Cambridge programme posed multiple delivery challenges, including:
- Complex multi-disciplinary commissioning across a large and live operational rail environment
- A short and fixed-window Christmas blockade, requiring high-intensity mobilisation
- Delivery across 32 route miles, including multiple interfaces and operational constraints
- Ongoing development of the new SmartLock system, resulting in revisions and repeat visits to equipment during the build phase
- The need to maintain the highest safety and quality standards while delivering under significant time pressure
Despite these constraints, Deploy supported successful commissioning and completion of Stage 2 works, replacing an SSI system that had been in place since 1984 with a modern, safe and future-proof solution.
Deploy’s Role
Deploy supported the project at every level, providing qualified, experienced personnel across key commissioning and installation roles, including:
- Engineering Supervisors
- Level Crossing Attendants
- Level Crossing Supervisors
- Signalling Installers
- MOD 5s
- Team Leaders
- Functional Testers
- Testers in Charge
- Possession Planner
- Civils Gangs
- On-site Deploy internal staff
Deploy’s flexible resourcing model allowed the programme to scale rapidly during critical periods, providing robust support throughout both the lead-up phase and the blockade itself.
Key Delivery Highlights
Blockade Mobilisation
The blockade commenced with the successful taking of 45 level crossings on Christmas Eve in just over an hour, improving on the previous year’s performance and setting a strong operational foundation for the remainder of the blockade.
CSIE – Signalling Delivered for Cambridge South Station
Deploy supported delivery of the signalling system in preparation for the planned opening of Cambridge South Station. Outputs included:
- 5x SMIOs
- 8x FSPs
- 33x signals
- 76x axle counters
- 20x AWS and 38x TPWS
- 10x point ends
C3R – Stage 2 Control Systems Package
Deploy supported the successful delivery and commissioning of the Stage 2 control systems package, including:
- 3x new MCS-Infinity workstations (Cambridge South, Cambridge Central and Foxton)
- 1x new LX desk, updated with MCS-Infinity screens and LX pods
- A first-in-class SSM desk, configured to 4x new MCS-Infinity workstations
- Recovery of the existing Henry Williams NX panel, ending 43 years of NX panel operation at Cambridge PSB
- Installation and testing of 9x fringe sites from Liverpool Street IECC to Stansted via Romford ROC
Measured Outputs (Stage 2 & CSIE Build)
The scale of delivery across the Stage 2 and CSIE build is evidenced by the following completed outputs:
- 400,000m of cable installed
- 22 SMIOs built, fitted out and delivered
- 94 signals installed or altered
- 226 axle counters installed
- 150 SMIO DBs built and terminated
- 104 TPWS loops installed
- 63 AWS magnets installed
- 31 LODs installed
- 1 level crossing fully renewed and 7 existing level crossings enabled
- 60 ends of points enabled
In parallel to lineside works, Deploy supported extensive systems installation activity within the PSB and at Foxton Gate Box, including:
- Installation of new signaller control desks
- SmartLock cubicle installations
- Full interface wiring works
- Testing and integration support
These works represented a significant programme in their own right and were completed within a constrained delivery window.
Outcome
Deploy’s support contributed to the successful commissioning and delivery of Stage 2 on the Cambridge programme during the Christmas 2025 blockade. The works delivered a modernised control and signalling system, enabling improved reliability, maintainability and readiness for future enhancement projects in the area.
What’s Next
Following the successful completion of Cambridge Stage 2 and CSIE commissioning, the programme transitions into the next phase: Croxton and Stage 3.








