Track renewal machines are complex systems designed to automate the replacement and improvement of track components such as rails, sleepers (ties), and ballast in railway infrastructure. These machines typically have their propulsion systems and can perform multiple functions in an integrated manner. For example, they can sequentially remove existing rails and sleepers, lay new materials, clean and redistribute ballast, and adjust track geometry.

Preparation and Commissioning Process

Before the operation begins, the track renewal machine is positioned appropriately along the rail alignment at the worksite. During this preparation stage:

Hydraulic, pneumatic, and mechanical systems of the machine are checked.
Operators program the systems based on route data, characteristics of the old superstructure, and the type of materials (rails and sleepers) to be renewed.
Safety and signaling measures are implemented.

This phase is critical not only for renewal efficiency but also for worker safety.

Removal of Old Rails and Sleepers

Rail Separation System: Frees the rails by removing fasteners such as clips and spikes.
Sleeper Removal Mechanism: Uses special gripping tools to lift and transport old sleepers.
Rail Transport Conveyor: Transfers removed rails to a storage platform or recycling unit.

Rails must be removed in a controlled manner to avoid bending or deformation.

Ballast Cleaning and Leveling

Ballast Separator/Cleaner: Separates the old ballast from soil and coarse particles via a screening system.
Conveyor Belts: Return reusable ballast to the track bed and direct worn-out ballast to waste compartments.
Surface Leveling Blades: Prepare the subgrade to ensure proper seating of the new sleepers.

During this stage, the track geometry is precisely monitored using GPS and laser measurement systems.

_{Track Renewal Machine (Generated with the Assistance of Artificial Intelligence)}

Installation of New Sleepers

Sleeper Feeding Unit: Sleepers are preloaded onto the machine.
Robotic Placement System: Lays the sleepers on the track bed at exact intervals and positions.
Position Control System: Laser and digital sensors monitor the accuracy of sleeper placement in real time.

Laying and Joining of New Rails

Rail Placement Mechanism: Delivers new rails over the sleepers via a conveyor system.
Fastening Equipment: Secures rails to sleepers using clips or bolts.
Rail Welding and Joining: If long welded rail (LWR) systems are used, rails are joined using thermite welding or mobile welding machines.

Track Geometry Adjustment (Tamping and Stabilization)

Tamping Unit: Adjusts the position of sleepers using hydraulic tampers, ensuring accurate alignment in both horizontal and vertical planes.
Stabilizer Unit: Applies vibrations to stabilize the track and minimize subsequent settlements.
Laser/Infrared Monitoring: Continuously checks alignment using geometry control sensors.

Testing and Measurement Process

The renewed track is temporarily tested using low-speed freight trains.
Laser-based measuring devices (e.g., EM-SAT or EM100) are used to check alignment deviations, superelevation, gradients, and flatness.
If necessary, the machines perform a second pass for corrections along the same route.

Additional Technological Systems

GPS-Based Automatic Navigation: Uses GPS to determine the machine’s position and guide it along predefined alignments with precision.
PLC (Programmable Logic Controller) Control Panel: Enables safe, flexible, and programmable control of machine functions via industrial automation.
Remote Monitoring and Fault Diagnostics: Sends real-time machine operation data to a central unit via network connection, enabling early fault detection.

Advantages of Track Renewal Machines

Time Efficiency: Enables faster renewal compared to manual methods.
Labor Productivity: More work can be accomplished with less manpower.
Safety: Automated systems reduce the risk of workplace accidents.
Quality: Delivers standardized and consistent renewal quality.

Areas of Application

Track renewal machines are particularly preferred on high-speed rail lines and heavily used main lines. These machines ensure that the infrastructure remains durable and safe for long-term service.

Railway track renewal machines, with their integrated multi-function systems, have replaced traditional methods by offering low error rates, high efficiency, and reduced dependence on manual labor. In Türkiye, especially in TCDD’s modernization projects, these machines are widely used both on intercity main lines and high-speed rail corridors.

Railway Track Renewal Machine