At Sandilands, a critical section of the track had reached the end of its service life. The Switch and Crossing unit was deteriorating, historic slab issues were causing ongoing concern, and the existing drainage was no longer performing as it should. To protect reliability and keep passengers moving safely, a full renewal was essential.
PLS was engaged to deliver the civil engineering elements of the scheme, working in close partnership with VolkerRail, who led the track installation. Together, the teams faced a single, non negotiable constraint: the entire scope had to be completed within a 15 day blockade.
The Challenge
The brief was straightforward on paper but demanding in reality. It required the full removal and replacement of a life expired unit, the rectification of known historic defects in the existing track slab, and a complete modernization of a drainage system that was no longer fully operational. Most importantly, the team had to ensure a zero overrun handback to the railway on time, providing a more resilient asset with minimal future disruption. All of this had to be delivered within a continuous 15 day possession, with multiple disciplines working in tight proximity and no room for programme slippage.
Our Role: The Civils Foundation
PLS was responsible for the civils scope, providing the structural groundwork that underpinned the track installation by VolkerRail. Our focus was on getting the fundamentals right, specifically the structure, drainage, and access.
Our delivery began with precision rail release, involving the saw cutting of approximately 1km of plain line rail to free the existing unit and create clean interfaces for removal. We then moved into strategic breakouts, which included removing concrete shoulders around the old unit and carefully breaking out two specific sections of the stage one slab to address a historic structural fault. This ensured the new unit was not built on a compromised foundation.
To improve drainage resilience, we installed a new 3m deep soakaway chamber to significantly boost local capacity and renewed other drainage elements that were no longer functional. The structural reconstruction followed, where we cast new sections of the stage one slab. Once VolkerRail had installed the new unit to the correct line and level, we cast new concrete shoulders around it to provide robust, long term lateral support. As a finishing touch, we installed new block paving between concrete upstands to create a durable and safe surface for future inspections and maintenance.
Working Within the 15 Day Window
The blockade was the defining feature of this project. With only 15 days on the clock, planning and coordination were everything. Saw cutting, breakout, drainage, slab reconstruction, track installation, and final concreting were all choreographed so that one activity flowed into the next without a second of idle time.
PLS and VolkerRail worked as an integrated partnership, sharing daily progress updates and adjusting sequencing in real time to protect the critical path. Despite the compressed timeline, we maintained rigorous quality control and testing processes for reinforcement, concrete curing, and drainage to ensure the asset would perform for decades to come.
Overcoming the Hidden Issues
A few aspects of the job required expert attention to fix legacy problems. The existing stage one slab had known issues, and rather than building over them, we took the time to break out and reconstruct the affected sections. This added complexity but ensured the new unit was founded on sound concrete.
Water management was another priority. By introducing the 3m soakaway and renewing non functional pipes, we significantly improved how the site handles wet weather, reducing the risk of future track faults. Furthermore, the new concrete shoulders had to support an installation with incredibly tight tolerances, requiring our formwork to be managed with millimetre precision to match the track geometry set by VolkerRail.
The Outcome
By the end of the 15 day blockade, the Sandilands site was transformed. A new unit was successfully installed on a structurally sound, newly cast slab, and upgraded drainage now protects the asset from water related degradation. New concrete shoulders provide the necessary support for high performance rail, while block paved areas offer a clean, safe environment for maintenance teams. Most importantly, the route reopened as planned with an on time handback and no disruption to the wider timetable.
Why It Matters
The Sandilands renewal is a prime example of how PLS approaches complex rail civils. We do not just replace like for like; we fix the underlying issues such as slab faults and drainage to extend asset life. We thrive in high pressure, possession constrained environments and collaborate seamlessly with partners like VolkerRail to deliver a single, integrated solution.
