The rail fastening system is the main part that connects the rail and the sleeper and ensures the reliability and stability of the track. In ballastless track, the elasticity of the track structure depends largely on the fastening system, and the accuracy of the track geometry is adjusted and maintained through the fastening system. For high-speed railways the fastening system has a direct influence on running safety and ride comfort.
Core Functions of the Fastening System
Fastening the steel rail and sleeper together: a fastening system consists of rail clips, rail spikes, rail anchors, tie plates and other fasteners that work together to create a stable and solid track structure
Maintaining the rail gauge: the system keeps the track gauge and prevents vertical and horizontal movement of the steel rails by connecting them tightly to the sleepers
Controlling elasticity and damping: the system provides the required elasticity, absorbs impact and vibration from train loads and protects the sleeper and ballast
Ensuring safety: the stability of the rail, rail joints and fastening system directly determines the safety of trains and vehicles
Wedge-Type Fastening for Timber and Steel Sleepers
The wedge-type fastening is commonly used on timber and steel sleepers for ordinary railways, light rails and low-speed lines. The wedge presses the rail base against the sleeper and is secured by spikes and bolts.
| Component | Quantity | Material |
|---|---|---|
| Wedge clip | 2 | Q235 |
| Screw spike | 2 | Grade 4.6 Q235, grade 5.6 35#, grade 8.8 45# |
| High-strength bolt | 4 | Grade 4.6, 5.6 or 8.8 |
| Hex nut | 2 | Grade 5 35#, grade 8 45# |
| Double coil spring washer | 2 | 65Mn |
Tension Clamp Fastening for Concrete Sleepers
Tension clamp fastening systems are known for excellent fatigue resistance and stability and are widely applied in high-speed railways and urban rail transit on concrete sleepers. The tension clip is driven over the shoulder and presses the rail base onto the rail pad.
| Component | Quantity | Material |
|---|---|---|
| Tension clip | 2 | 60Si2CrA, 38Si7 |
| Screw spike | 2 | Grade 4.6 Q235, grade 5.6 35#, grade 8.8 45# |
| Flat washer | 2 | Q235 |
| Plastic dowel | 2 | HDPE or reinforced nylon 66 |
| Guide plate | 2 | Reinforced nylon 66 |
| Rail pad | 1 | EVA or rubber |
E-Type Fastening for Heavy-Load Lines
The E-type fastening system is one of the most widely used systems for concrete sleepers, suitable for ordinary railways, heavy-load railways and the standard track of high-speed railways. Two elastic clips press the rail base onto the pad through cast shoulders.
| Component | Quantity | Material |
|---|---|---|
| E clip | 2 | 60Si2MnA, 60Si2CrA |
| Shoulder | 2 | QT500-7, QT450-10 |
| Rail pad | 1 | HDPE, rubber or EVA |
| Insulator | 2 | Reinforced nylon 66 |
Selection and Maintenance
Select the fastening system according to sleeper type, rail section, axle load, track speed and whether the line is ballasted or ballastless. During maintenance, check clip toe load, insulator condition, pad wear and spike torque, and replace damaged components promptly to keep the fastening force within specification.
Frequently Asked Questions
What is the main function of a rail fastening system? It fixes the rail to the sleeper or track plate and maintains the gauge and stability of the track.
Which fastening system suits high-speed railways? Tension clamp and E-type fastening systems on concrete sleepers are widely used for high-speed and urban rail lines.
What components make up a fastening system? Typical components are elastic clips, screw spikes, flat washers, plastic dowels, guide plates, rail pads and insulators.
Why is the fastening system important for ballastless track? It provides most of the elasticity and allows the track geometry to be adjusted and maintained accurately.
How often should fasteners be inspected? Fasteners should be inspected at regular maintenance intervals, with clip toe load, pad condition and spike torque checked and corrected.
