EN 15427-1-2: Friction Management – Wheel-Rail Contact – Part 1-2: Lubricants

What is EN 15427-1-2?

EN 15427-1-2 is a European Standard titled “Railway applications – Wheel/rail friction management – Part 1-2: Equipment and Application – Lubricants.” While Part 1-1 focuses on the mechanical equipment used for lubrication, Part 1-2 focuses on the chemical and physical characteristics of the Lubricants themselves.

In Infrastructure Management, managing the Wheel-Rail Interface is vital. This standard ensures that the lubricants used to protect the rail flange and the wheel flange are effective, stable, and safe for the environment.

Technical Requirements for Lubricants

Lubricants in the rail environment must perform under extreme pressure and varying temperatures. EN 15427-1-2 mandates specific properties to ensure Friction Management is consistent:

• Friction Characteristics: The lubricant must effectively reduce the friction coefficient specifically at the flange (typically to below 0.1) without migrating to the rail head, where it would compromise Braking Performance.
• Viscosity and Pumpability: Requirements for the lubricant’s behavior across a wide temperature range (e.g., -40°C to +80°C), ensuring it can be sprayed or applied by onboard systems without clogging.
• Adhesion and Persistence: The ability of the lubricant to “stick” to the wheel flange and transfer to the rail gauge corner, remaining effective for several kilometers of travel.

Environmental and Health Standards

Because these lubricants are applied in an open environment, EN 15427-1-2 places heavy emphasis on ecological safety:

• Biodegradability: Mandatory testing to ensure the lubricant breaks down naturally and does not contaminate soil or groundwater.
• Toxicity: Restrictions on heavy metals and hazardous chemicals to protect both maintenance staff and the Rail Environment.
• Compatibility: Ensuring the lubricant does not degrade plastic or rubber components on the Rolling Stock (e.g., brake hoses or seals).

Testing and Quality Assurance

To be certified under EN 15427-1-2, a lubricant must undergo standardized tests:

• 4-Ball Test: A laboratory test to determine the “Weld Point” and wear protection under extreme pressure.
• Sprayability Test: Validating that the lubricant forms a consistent film when applied through the high-pressure nozzles of onboard Flange Lubrication systems.
• Corrosion Protection: Testing the lubricant’s ability to protect the metal surfaces from rust in humid or saline environments.

Comparison: Flange Lubricants vs. Top-of-Rail (TOR) Materials