What is the primary purpose of the EN 16185-2 standard?

The primary purpose of EN 16185-2 is to define standardized test methods for the braking systems of multiple unit (MU) trains. It provides a consistent framework to verify that a train's braking performance meets the design requirements, ensuring safety, reliability, and interoperability across railway networks.

What is the difference between a 'type test' and a 'routine test' in EN 16185-2?

A type test is a comprehensive set of tests performed once on a new train design to validate its overall performance and safety across all operating conditions. A routine test is a less extensive set of functional checks performed on every unit produced in a series to ensure manufacturing consistency and quality control.

Why is thermal capacity testing important for train brakes?

Thermal capacity testing is crucial to ensure that a train's brakes do not lose their effectiveness (a phenomenon known as 'brake fade') when subjected to high heat from prolonged or repeated use, such as descending a long gradient. The test verifies that the brakes can safely stop the train even after reaching their maximum operational temperature.

Does EN 16185-2 specify the required stopping distances for trains?

No, EN 16185-2 does not specify the performance values like stopping distances. It specifies the *methods* and *procedures* for how to conduct the tests to measure these values. The required performance criteria and stopping distances are defined in other standards, such as EN 16185-1 (Requirements), or in the specific Technical Specifications for Interoperability (TSI).

EN 16185-2: Europe’s Standard for Safer Train Braking

EN 16185-2 defines essential test methods for multiple unit train braking systems. It ensures safety, reliability, and interoperability through rigorous type and routine testing.

December 15, 2024 2:02 am

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Understanding EN 16185-2: The Standard for Testing Multiple Unit Train Braking Systems

EN 16185-2 is a European standard that specifies the essential test methods for the braking systems of multiple unit (MU) trains. Its primary function is to provide a unified framework for verifying that the braking performance of these vehicles meets the design requirements, safety criteria, and operational expectations defined primarily in EN 16185-1.

This standard is critical for ensuring the safety, reliability, and interoperability of modern passenger trains across European networks. By standardizing the testing procedures, EN 16185-2 ensures that all new or modified multiple units are evaluated against a common, rigorous benchmark, regardless of the manufacturer or operator.

Core Objectives of EN 16185-2 Testing

The test methods outlined in the standard are designed to validate several key aspects of the braking system. The ultimate goal is to build confidence in the train’s ability to stop safely and predictably under all foreseeable conditions. Key objectives include:

Performance Verification: To confirm that the train’s actual stopping distances and deceleration rates meet or exceed the calculated values and regulatory requirements.
System Functionality: To ensure all components of the braking system (pneumatic, electric, electro-pneumatic, and dynamic) function correctly, both individually and as an integrated system.
Safety Under Failure: To test the braking system’s performance in degraded modes, such as a loss of primary power or a component failure, ensuring the train can still be brought to a safe stop.
Thermal Capacity Validation: To assess the brake system’s ability to withstand high thermal loads during repeated or prolonged applications without significant performance degradation (brake fade).
Adhesion Management: To verify the effectiveness of the Wheel Slide Protection (WSP) system in optimizing braking effort under low-adhesion conditions, preventing wheel damage and maximizing deceleration.

Key Test Categories Defined in the Standard

EN 16185-2 categorizes tests into two main groups, each serving a distinct purpose in the vehicle’s lifecycle from design validation to series production.

Type Tests

Type tests are comprehensive and exhaustive tests performed on the first train of a new series, or on a train that has undergone significant modifications to its braking system. The purpose of a type test is to fully validate the design and prove its compliance with all performance and safety requirements. These tests are intensive and cover the full operational envelope of the train. Key type tests include:

Stopping Distance Tests: Measuring the actual distance required to stop from various initial speeds using different brake commands (e.g., service brake, emergency brake). These are performed under various load conditions (empty, normal load, exceptional load).
Emergency Braking Tests: Specific tests to verify the performance and response time of the emergency braking system, which is the highest safety-critical function. This includes tests for passenger emergency brake activation.
Thermal Capacity Tests: Simulating a demanding operational scenario, such as descending a long, steep gradient, to heat the brakes to their maximum expected temperature. A subsequent stopping test is performed to ensure performance is not unacceptably degraded.
WSP System Performance Tests: Conducted on track with artificially reduced adhesion (e.g., wetted rails) to verify the WSP system’s ability to control wheel slip and optimize the braking distance.
Response Time Measurement: Measuring the time delay from the moment a brake command is initiated by the driver until a specified brake force is achieved throughout the train.

Routine Tests

Routine tests are performed on every subsequent train unit produced in a series after the design has been validated by the type test. These tests are less extensive and are designed to confirm that the manufacturing and assembly processes are consistent and that each unit’s braking system functions identically to the type-tested unit. The focus is on quality control and functional verification rather than design validation. Examples include:

Functional checks of brake controllers and indicators.
Pneumatic leakage tests to ensure the integrity of the air pipe system.
Basic brake application and release tests to confirm correct operation.
Verification of safety-critical settings and software configurations.

Comparison Table: Type Tests vs. Routine Tests

Aspect	Type Tests	Routine Tests
Purpose	To validate the overall design and performance of the braking system for a new train type.	To ensure manufacturing consistency and functionality for each unit in a series production.
Scope	Comprehensive, exhaustive, and covers all operational and environmental conditions.	Limited to key functional checks and verification of critical parameters.
When Performed	Once, on a pre-series or the first-of-class unit before entering service.	On every single unit produced after the type test has been passed.
Example Tests	Full stopping distance trials, thermal capacity validation, low-adhesion WSP tests.	Brake cylinder pressure checks, system leakage tests, basic functional verification.

The Role of EN 16185-2 in Railway Interoperability and Safety

The importance of EN 16185-2 extends beyond a single vehicle. By creating a standardized set of test procedures, it provides a common language for manufacturers, operators, and regulatory bodies. This harmonization is a cornerstone of the European Technical Specifications for Interoperability (TSI), which allows trains to operate seamlessly across national borders.

From a safety perspective, the standard is paramount. The rigorous testing methodologies it mandates provide objective evidence that a train’s most critical safety system—its brakes—will perform as expected. By testing for performance in normal, degraded, and emergency scenarios, EN 16185-2 directly contributes to minimizing risks and ensuring the protection of passengers, crew, and infrastructure.

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