EN 13146-6: Railway Applications – Track – Test Methods for Fastening Systems: Effect of Severe Environmental Conditions

What is EN 13146-6?

EN 13146-6 is a specialized testing standard titled “Railway applications – Track – Test methods for fastening systems – Part 6: Effect of severe environmental conditions.” In the Rail Environment, track components are exposed to salt spray, industrial pollutants, high humidity, and biological growth (such as fungi).

This standard provides the Technical Delivery Conditions for simulating these harsh environments in a laboratory setting. The goal is to ensure that the Fastening Systems—the clips, bolts, and baseplates that hold the rail to the sleeper—do not fail prematurely due to corrosion or degradation, which is vital for Operational Safety.

Testing Methodology and Exposure

The standard mandates a specific sequence of exposure to simulate a lifetime of environmental stress in a compressed timeframe. This typically involves:

• Salt Spray Testing: Subjecting the assembly to a continuous neutral salt spray (typically 5% NaCl solution) for a defined period (usually 240 to 480 hours).
• Humidity Cycles: Exposure to high humidity and temperature fluctuations to test the resilience of protective coatings and plastic components.
• Biological Assessment: Evaluating the resistance of non-metallic components (such as rail pads or plastic insulators) to mold and fungal growth that can occur in damp Ballasted Track environments.

Assessment Criteria

After the environmental exposure, the fastening system is evaluated not just on its appearance, but on its continued functionality:

• Dismantling Test: A critical requirement is that the system must still be able to be dismantled and reassembled using standard maintenance tools. If corrosion “seizes” the bolts or clips, the system fails the test.
• Clamping Force: The system must retain its minimum required clamping force (toe load) even after the exposure, ensuring the rail remains securely held.
• Electrical Resistance: For tracks using Slab Track or signaling circuits, the insulation must still function effectively despite any surface contamination or biological growth.

Relevance to Infrastructure Management

For Infrastructure Management, compliance with EN 13146-6 is essential when selecting components for coastal lines, tunnels, or high-pollution industrial zones. It ensures that the lifecycle costs of the track are minimized by preventing frequent replacements due to environmental failure.

Comparison: EN 13146-6 Testing vs. Normal Operating Conditions