Rhomberg Sersa Australia (RSA) partnered with Sydney Trains to deliver the Coalcliff Tunnel Track Reconstruction Project, implementing the IVES ballast less track system to improve track performance and long-term maintainability within this critical rail asset.
Constructed in 1888, Coalcliff Tunnel is a historically significant 1,000m-long oviform brick tunnel and remains one of the few single-track constraints on the Illawarra Line. The tunnel environment presents unique operational and construction challenges, including restricted access, low overhead wiring clearances, and ongoing water ingress, requiring a highly planned, engineered solution to deliver reliable long-term performance.
Scope of Works
- Enabling works including temporary lighting, protection measures and tunnel water management systems.
- Established a tunnel deformation/convergence monitoring program across the full 1,000m tunnel length.
- Removed existing ballasted track and prepared the tunnel floor for reconstruction.
- Lowered the tunnel floor using a cold milling machine to achieve design clearances and formation requirements.
- Constructed the asphalt track slab and central drainage channel, including quality control verification.
- Installed and aligned the IVES ballastless track system, completing certification and handback for rail operations.
Innovation, Delivery & Outcomes
DETAILED PLANNING AND CONSTRUCTABILITY
RSA completed meticulous planning and constructability workshops to safely deliver works in a constrained tunnel environment, supported by digital engineering tools for visualisation, clash detection and verification.
MANAGING WATER INGRESS AND TUNNEL CONDITIONS
The tunnel presented persistent water seepage and wet working conditions. RSA implemented temporary water management systems and drainage controls to separate construction water from ongoing seepage, supporting safe access and quality installation.
IMPROVED TRACK PERFORMANCE AND REDUCED MAINTENANCE
The IVES ballastless track solution significantly reduces maintenance demand within the tunnel, increasing track availability and reducing whole-of-life costs. Over time, the improved track quality supports smoother passenger ride quality, reduced rail wear, lower rollingstock maintenance requirements and reduced derailment risk.
