Does EN 50736 cover safety functions?

No. EN 50736 covers the environmental and physical testing (type testing) of the hardware. The functional safety logic (SIL levels) is covered by EN 50126, EN 50128, and EN 50129.

Is EN 50736 mandatory for onboard equipment?

No. Equipment mounted on trains (rolling stock) must comply with EN 50155. EN 50736 is exclusively for trackside (stationary) signalling and telecommunication equipment.

What is the relationship between EN 50736 and EN 50125-3?

EN 50125-3 defines the environmental parameters (e.g., 'What is the maximum wind speed?'). EN 50736 defines the test procedures to prove the equipment can survive those parameters (e.g., 'How long do we vibrate the device?').

The Shield for the Trackside: EN 50736 Standard Explained

The missing link for trackside hardware. EN 50736 defines the environmental test requirements for stationary railway signaling equipment, complementing EN 50155.

December 16, 2025 5:54 am

What is EN 50736?

EN 50736 is the European Standard (CENELEC) titled “Railway applications – Communication, signalling and processing systems – Test requirements for signalling and telecommunication equipment.”

For decades, the railway industry relied on EN 50155 for testing electronic equipment on trains (rolling stock). However, there was no single, unified standard for the testing of stationary trackside equipment (such as axle counter processors, balises, or switch controllers). EN 50736 fills this gap by defining the type testing requirements specifically for trackside hardware, ensuring it can withstand the harsh outdoor railway environment.

Scope and Application

This standard applies to all signaling and telecommunication (S&T) equipment installed along the track or in technical rooms. It focuses on physical and environmental durability rather than functional safety logic.

Target Equipment: Wayside controllers, Radio Block Centers (RBC), Object Controllers, and trackside sensors.
Key Tests: Temperature cycling, vibration, shock, humidity, and electromagnetic compatibility (EMC).
Relation to EN 50125-3: EN 50736 defines how to test compliance against the environmental conditions described in EN 50125-3.

Comparison: EN 50736 vs. EN 50155

It is often helpful to think of EN 50736 as “The EN 50155 for Trackside.” While they share similar testing methodologies, their application environments differ significantly.

Feature	EN 50155	EN 50736
Target Location	Onboard (Rolling Stock)	Trackside (Wayside / Technical Rooms)
Vibration Profile	High (Mobile environment)	Variable (Static, but subject to passing train vibrations)
Temperature Classes	Tx Classes (e.g., T1, T3)	Aligned with EN 50125-3 (Outdoor/Indoor classes)
Primary Focus	Vehicle durability	Infrastructure durability

Why is EN 50736 Important?

Before EN 50736, manufacturers often had to adapt EN 50155 requirements for trackside products, which led to over-engineering (testing for conditions that don’t exist on the ground) or ambiguity in tenders. EN 50736 provides a clear baseline for procurement, ensuring that a signaling computer installed in a cabinet in Sweden or Spain meets a harmonized standard for reliability.