The WJ-8 railway fastener system is specially designed for high-speed railway shoulder-barred ballastless tracks. Its scientific and reasonable composition ensures the stability and safety of high-speed railway tracks. The system mainly consists of the following components:
| WJ-8 Rail Fastening System Technical Requirements | |||
| Fastener type | WJ-8 type fastener | ||
| Taxonomy | With iron rail pad (thickness 16mm) | ||
| Withstand lateral force | Sustained by concrete shoulders | ||
| Connection with the foundation | Embedded plastic casing | ||
| Embedded member pull-out resistance | Not less than 60kN | ||
| Buckle | Types of | W1 type | Type X2 |
| Buckle pressure | >9kN | 6kN | |
| Strike | 14mm | 12mm | |
| Fastening method | Bolt fastening | ||
| Tightening torque | About 160Nm | About 110Nm | |
| Rail longitudinal resistance | >9kN | 4kN | |
| iron rail pad fastening torque | -- | ||
| Elastic cushion | Setting | A cushion layer (rubber pad or composite rubber pad) is arranged under the rail, and an elastic cushion layer (thermoplastic elastomer foaming pad) is arranged under the iron rail pad plate. | |
| size | Class A | Class B | |
| Under rail rubber pad: 175 × 156 × 4 | |||
| rail pad under the iron rail pad 285×150×12 | |||
| Under-arc cushion stiffness | >300 kN/mm | ||
| Sub-layer cushion stiffness | 30～40kN/mm | 20~30kN/mm | |
| Rail height | High rail surface | 208 | |
| Adjustment amount | 30mm | ||
| Adjustment method | By adjusting the height of the pad between the rail and the iron rail pad to achieve 10mm adjustment; padding the pad on the sleeper bearing groove to achieve 20mm adjustment. The filling pad can be adjusted steplessly. | ||
| gauge | Adjustment amount | ±10mm | |
| Adjustment method | It is realized by replacing the gauge baffles of different specifications. | ||
| Adjustment level | Level adjustment, level 1mm | ||
| Rail joint treatment | In general, when the general gauge adjustment amount is large, replace the joint gauge baffle. | ||
| Applicable to ballastless track | Armless track structure | ||
| Drawing number and standard | Research Line 0604, Science and Technology Base [2007] 207 | ||
| Application condition | 250km/h | 350km/h passenger line | |
Spiral spikes: divided into S2 type and S3 type. When the fasteners are installed normally or the rail height adjustment does not exceed 15mm, the S2 type is used; if the height adjustment is greater than 15mm, the S3 type is used. It passes through the spring bar, iron pad and other components from top to bottom, and screws into the embedded sleeve to provide a stable buckle pressure for the spring bar.
Flat washers: installed on the spiral spikes, it can increase the contact area, disperse the pressure, prevent the components from loosening and wearing under long-term vibration, and protect the surface of the connected components.
Spring bars: There are two types: W1 and X2. The diameter of the W1 spring bar is 14mm, which is used in general areas; the diameter of the X2 spring bar is 13mm, which is used when small resistance fasteners are used on bridges. The spring bar tightly buckles the rail through its own elastic deformation, ensuring that the rail can still maintain the correct position under the dynamic force of the train.
Insulating gauge block: divided into type I and type II, type I is used in general sections, and type II is used at rail joints. It is set between the spring bar and the rail, which not only ensures the insulation performance of the fastener system, prevents current leakage from affecting the normal operation of the track circuit, but also assists in maintaining the gauge.
Gauge baffle: including WJ8 gauge baffle for general sections and WJ8 joint gauge baffle for rail joints. The WJ8 gauge baffle for general sections has eleven specifications from No. 2 to No. 12, No. 7 is used for standard gauge, of which No. 10, 11, and 12 can be used at rail joints; the WJ8 joint gauge baffle has eight specifications from No. 2 to No. 9, and No. 7 is also used for standard gauge. By replacing gauge baffles of different specifications, the gauge can be adjusted to meet the needs of track laying and later maintenance.
Rail pads: There are rubber pads used in general areas and composite pads that may be used on bridges. Rubber pads have good elasticity and vibration reduction properties, which can effectively buffer the impact of trains on tracks; composite pads are optimized in some performances according to the needs of special areas such as bridges, such as reducing line resistance.
Iron pads: They connect and support other components, and reliably transmit the vertical, lateral and longitudinal forces from the rails to the concrete shoulder or other sub-rail foundation structures. Their structural design enhances the stability of the entire fastener system.
Elastic pads under iron pads: They are divided into two categories, A and B, with a thickness of 12mm. Category A is used for passenger dedicated lines that also take into account freight, and Category B is used for passenger dedicated lines that only run passenger cars. The elastic pad further improves the overall elasticity of the fastener system, effectively absorbs the vibration and impact energy generated by train operation, and extends the service life of track components.
Embedded casing: Positioned in concrete sleepers or track plates, it provides a stable anchoring foundation for spiral spikes, ensuring that the spiral spikes will not loosen or fall off during long-term use, and ensuring the fastening effect of the fastener system.
Fine-adjustment pads under the rail and height adjustment pads under the iron pad: To meet the needs of adjusting the height of the rails, the system is equipped with fine-adjustment pads under the rail and height adjustment pads under the iron pad. The fine-adjustment pads under the rail are divided into four specifications according to thickness: 1mm, 2mm, 5mm and 8mm; the height adjustment pads under the iron pad are divided into two specifications according to thickness: 10mm and 20mm, and are composed of two pieces, which should be used in pairs. By using these pads, the height of the track can be accurately adjusted to adapt to different track laying and maintenance conditions.
The various components of the WJ-8 railway fastener system work together to ensure the stability, insulation, elasticity and flexibility of the high-speed rail track and the flexibility of the gauge and height adjustment from multiple dimensions, laying a solid foundation for the safe and smooth operation of the high-speed rail.