This technical guide provides an in-depth look at key CENELEC rail standards as they apply to rail profiles and fastening systems. The focus is on the material specifications, dimensional tolerances, and functional requirements that ensure safety, reliability, and interoperability across European railway networks.
Rail Profile Specifications: EN 13674 Series
The EN 13674 series is the cornerstone for railway rails, detailing the requirements for flat bottom vignole rails with a mass of 46 kg/m and above. This standard is divided into several parts, each addressing a specific aspect of rail manufacturing and quality assurance.
EN 13674-1: Flat Bottom Vignole Rails ≥ 46 kg/m
This part of the standard specifies the technical delivery conditions for rails, covering material properties, dimensional tolerances, and inspection procedures.
Material Properties and Steel Grades
The standard defines several steel grades, each engineered for different operational demands, from conventional lines to high-speed and heavy-haul applications. The primary grades are categorized by their hardness and tensile strength.
|
Grade |
Hardness (HBW) |
Tensile Strength (Rm) MPa |
Chemical Composition Highlights (% max unless specified) |
|
R200 |
200 – 240 |
≥ 680 |
C: 0.40-0.60, Si: ≤ 0.25, Mn: 0.70-1.10 |
|
R220 |
220 – 260 |
≥ 770 |
C: 0.45-0.65, Si: ≤ 0.35, Mn: 0.70-1.20 |
|
R260 |
260 – 300 |
≥ 880 |
C: 0.62-0.80, Si: ≤ 0.50, Mn: 0.80-1.25 |
|
R260Mn |
260 – 300 |
≥ 880 |
C: 0.60-0.82, Si: ≤ 0.50, Mn: 1.30-1.70 |
|
R320Cr |
320 – 360 |
≥ 1080 |
C: 0.60-0.80, Si: ≤ 0.50, Mn: 0.80-1.30, Cr: 0.80-1.20 |
|
R350HT |
350 – 390 |
≥ 1175 |
C: 0.71-0.82, Si: ≤ 0.50, Mn: 0.80-1.25 (Heat Treated) |
|
R350LHT |
350 – 390 |
≥ 1175 |
C: 0.65-0.80, Si: ≤ 0.50, Mn: 0.70-1.10 (Low-Alloy, Heat Treated) |
|
R400HT |
≥ 390 |
≥ 1280 |
C: 0.71-0.82, Si: ≤ 0.50, Mn: 0.80-1.25 (High-Hardness, Heat Treated) |
Note: These are simplified ranges. The standard provides precise limits for other elements like Phosphorus (P), Sulfur (S), and Aluminum (Al) to control weldability and reduce impurities.
Common Rail Profiles and Dimensions
While EN 13674-1 specifies the material and quality, the actual rail profiles are defined by other standards or national specifications that align with CENELEC rail standards principles. The most common profiles used in Europe include the 54E1 (UIC54) and 60E1 (UIC60).
Table of Nominal Dimensions for 60E1 (UIC60) Profile
|
Parameter |
Dimension (mm) |
Description |
|
Height |
172.0 |
Overall vertical dimension of the rail. |
|
Head Width |
72.0 |
Width of the running surface at its widest point. |
|
Base Width |
150.0 |
Overall width of the rail foot. |
|
Web Thickness |
16.5 |
Thickness of the vertical section connecting head and foot. |
|
Mass per Meter |
60.21 kg/m |
Nominal weight, crucial for structural calculations. |
|
Moment of Inertia (Ix) |
3055 cm⁴ |
Resistance to bending around the horizontal axis. |
|
Moment of Inertia (Iy) |
513 cm⁴ |
Resistance to bending around the vertical axis. |
|
Section Modulus (Head) |
335 cm³ |
Measure of the rail head’s resistance to bending stress. |
|
Section Modulus (Base) |
377 cm³ |
Measure of the rail base’s resistance to bending stress. |
EN 13674-2: Switch and Crossing Rails
This part adapts the requirements of EN 13674-1 for rails used in turnouts and complex trackwork. These rails often require tighter dimensional tolerances and specific steel grades to handle the high dynamic forces experienced at switches. They are typically non-heat-treated but can be produced from higher-grade steels like R320Cr to enhance wear resistance.
Rail Clips and Fastening Systems: EN 13481 Series
Rail fastening systems are critical for securing rails to sleepers, maintaining track gauge, and providing electrical insulation. The EN 13481 series outlines the performance requirements and testing procedures for these systems.
EN 13481-2: Fastening Systems for Concrete Sleepers
This standard is essential for modern ballasted track. It specifies the requirements for fastening systems on concrete sleepers, including criteria for longitudinal restraint, clamping force, and dynamic performance.
Rail Clip Functionality and Design
Rail clips, or elastic fastenings, are the primary components responsible for applying a clamping force to the rail foot. This force prevents the rail from moving longitudinally (creep) or rotating. CENELEC-compliant clips are designed to:
- Provide a specific clamping force: Typically between 8 kN and 12 kN per clip, depending on the system and application (e.g., high-speed vs. conventional).
- Maintain elasticity: The clip must be able to deflect under load and return to its original shape, absorbing energy and accommodating rail movements.
- Offer high fatigue life: Clips must withstand millions of load cycles without failure. EN 13481-2 requires testing up to 5 million cycles.
- Be corrosion resistant: Clips are often treated with anti-corrosion coatings to ensure a long service life in harsh environments.
Key Performance Parameters for Fastening Systems
|
Parameter |
Typical Requirement (for Category C systems) |
Description |
|
Clamping Force |
> 9 kN per clip |
The force exerted by the clip onto the rail foot, essential for longitudinal restraint. |
|
Longitudinal Restraint (Single Assembly) |
> 7 kN |
The resistance of the fastening system to rail slip under longitudinal forces (e.g., from braking/acceleration). |
|
Dynamic Stiffness (kdyn) |
< 100 MN/m (variable by application) |
The system’s resistance to vertical deflection under dynamic loads. A lower value |
