EN 15220: The Standard for Reliable Railway Brake Status Indicators

What is EN 15220?

EN 15220 is the European Standard that specifies the requirements for the design, testing, and manufacture of brake indicators used on rail vehicles. These devices are essential safety components that provide a visual representation of the current state of the vehicle’s braking system—specifically whether the brakes are “Applied” or “Released.”

In modern railway operations, particularly for long freight trains or passenger coaches with aerodynamic fairings, the actual brake blocks or discs are not always visible to the shunter or driver. EN 15220 ensures that the indicators mounted on the side of the wagon provide a 100% reliable report of the pneumatic or mechanical status of the brake cylinder.

Technical Design Requirements

The standard sets strict criteria for how these indicators must function to prevent false readings, which could lead to “dragging brakes” (resulting in wheel flats or fires) or the mistaken belief that a train is secured. Key requirements include:

• Visual Signaling: Standardized color coding is mandatory—Red indicates the brake is applied, and Green indicates the brake is released.
• Mechanical Reliability: The indicator must be directly linked to the brake cylinder pressure or the mechanical rigging to ensure the display reflects the actual physical state of the brakes.
• Environmental Durability: Since they are mounted externally, indicators must withstand extreme temperatures, vibrations, and high-pressure ballast impact without losing legibility.
• Visibility: The display must be clearly readable from a distance of several meters in both daylight and low-light conditions.

Types of Indicators covered by EN 15220

While the most common indicators are pneumatic (activated by air pressure), EN 15220 also covers electrical and mechanical variants used in different types of rolling stock.

Comparison: Brake Indicator Status vs. Operational Reality

Importance for Maintenance and Safety

Compliance with EN 15220 is a prerequisite for TSI (Technical Specifications for Interoperability) certification. During a “Brake Test” (the procedure performed before a train departs), the inspector walks the length of the train. The indicators serve as the primary source of truth. If an indicator shows green but the brakes are dragging, it indicates a mechanical failure in the rigging; if it shows red when it should be green, it points to a pneumatic release failure.